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1 | <!-- |
2 | ||
3 | lxc: linux Container library | |
4 | ||
5 | (C) Copyright IBM Corp. 2007, 2008 | |
6 | ||
7 | Authors: | |
8 | Daniel Lezcano <daniel.lezcano at free.fr> | |
9 | ||
10 | This library is free software; you can redistribute it and/or | |
11 | modify it under the terms of the GNU Lesser General Public | |
12 | License as published by the Free Software Foundation; either | |
13 | version 2.1 of the License, or (at your option) any later version. | |
14 | ||
15 | This library is distributed in the hope that it will be useful, | |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | Lesser General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU Lesser General Public | |
21 | License along with this library; if not, write to the Free Software | |
22 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
23 | ||
24 | --> | |
25 | ||
26 | <!DOCTYPE refentry PUBLIC @docdtd@ [ | |
27 | ||
28 | <!ENTITY seealso SYSTEM "@builddir@/see_also.sgml"> | |
29 | ]> | |
30 | ||
31 | <refentry> | |
32 | ||
33 | <docinfo><date>@LXC_GENERATE_DATE@</date></docinfo> | |
34 | ||
35 | <refmeta> | |
36 | <refentrytitle>lxc.container.conf</refentrytitle> | |
37 | <manvolnum>5</manvolnum> | |
38 | </refmeta> | |
39 | ||
40 | <refnamediv> | |
41 | <refname>lxc.container.conf</refname> | |
42 | ||
43 | <refpurpose> | |
44 | LXC container configuration file | |
45 | </refpurpose> | |
46 | </refnamediv> | |
47 | ||
48 | <refsect1> | |
49 | <title>Description</title> | |
50 | ||
51 | <para> | |
b9986e43 CB |
52 | LXC is the well-known and heavily tested low-level Linux container |
53 | runtime. It is in active development since 2008 and has proven itself in | |
54 | critical production environments world-wide. Some of its core contributors | |
55 | are the same people that helped to implement various well-known | |
56 | containerization features inside the Linux kernel. | |
55fc19a1 SG |
57 | </para> |
58 | ||
59 | <para> | |
b9986e43 CB |
60 | LXC's main focus is system containers. That is, containers which offer an |
61 | environment as close as possible as the one you'd get from a VM but | |
62 | without the overhead that comes with running a separate kernel and | |
63 | simulating all the hardware. | |
55fc19a1 SG |
64 | </para> |
65 | ||
66 | <para> | |
b9986e43 CB |
67 | This is achieved through a combination of kernel security features such as |
68 | namespaces, mandatory access control and control groups. | |
69 | </para> | |
70 | ||
71 | <para> | |
eb4225a0 | 72 | LXC has support for unprivileged containers. Unprivileged containers are |
b9986e43 CB |
73 | containers that are run without any privilege. This requires support for |
74 | user namespaces in the kernel that the container is run on. LXC was the | |
75 | first runtime to support unprivileged containers after user namespaces | |
76 | were merged into the mainline kernel. | |
77 | </para> | |
78 | ||
79 | <para> | |
80 | In essence, user namespaces isolate given sets of UIDs and GIDs. This is | |
81 | achieved by establishing a mapping between a range of UIDs and GIDs on the | |
82 | host to a different (unprivileged) range of UIDs and GIDs in the | |
83 | container. The kernel will translate this mapping in such a way that | |
84 | inside the container all UIDs and GIDs appear as you would expect from the | |
85 | host whereas on the host these UIDs and GIDs are in fact unprivileged. For | |
86 | example, a process running as UID and GID 0 inside the container might | |
87 | appear as UID and GID 100000 on the host. The implementation and working | |
88 | details can be gathered from the corresponding user namespace man page. | |
bdcbb6b3 | 89 | UID and GID mappings can be defined with the <option>lxc.idmap</option> |
b9986e43 CB |
90 | key. |
91 | </para> | |
92 | ||
93 | <para> | |
94 | Linux containers are defined with a simple configuration file. Each | |
95 | option in the configuration file has the form <command>key = | |
96 | value</command> fitting in one line. The "#" character means the line is a | |
97 | comment. List options, like capabilities and cgroups options, can be used | |
98 | with no value to clear any previously defined values of that option. | |
99 | </para> | |
100 | ||
101 | <para> | |
eb4225a0 | 102 | LXC namespaces configuration keys use single dots. This means complex |
7fa3f2e9 | 103 | configuration keys such as <option>lxc.net.0</option> expose various |
104 | subkeys such as <option>lxc.net.0.type</option>, | |
2e44ae28 | 105 | <option>lxc.net.0.link</option>, <option>lxc.net.0.ipv6.address</option>, and |
b9986e43 | 106 | others for even more fine-grained configuration. |
55fc19a1 SG |
107 | </para> |
108 | ||
109 | <refsect2> | |
110 | <title>Configuration</title> | |
111 | <para> | |
b9986e43 CB |
112 | In order to ease administration of multiple related containers, it is |
113 | possible to have a container configuration file cause another file to be | |
114 | loaded. For instance, network configuration can be defined in one common | |
115 | file which is included by multiple containers. Then, if the containers | |
116 | are moved to another host, only one file may need to be updated. | |
55fc19a1 SG |
117 | </para> |
118 | ||
119 | <variablelist> | |
c464fd7e SG |
120 | <varlistentry> |
121 | <term> | |
122 | <option>lxc.include</option> | |
123 | </term> | |
124 | <listitem> | |
125 | <para> | |
126 | Specify the file to be included. The included file must be | |
127 | in the same valid lxc configuration file format. | |
128 | </para> | |
129 | </listitem> | |
130 | </varlistentry> | |
55fc19a1 SG |
131 | </variablelist> |
132 | </refsect2> | |
133 | ||
134 | <refsect2> | |
135 | <title>Architecture</title> | |
136 | <para> | |
b9986e43 CB |
137 | Allows one to set the architecture for the container. For example, set a |
138 | 32bits architecture for a container running 32bits binaries on a 64bits | |
139 | host. This fixes the container scripts which rely on the architecture to | |
140 | do some work like downloading the packages. | |
55fc19a1 SG |
141 | </para> |
142 | ||
143 | <variablelist> | |
c464fd7e SG |
144 | <varlistentry> |
145 | <term> | |
146 | <option>lxc.arch</option> | |
147 | </term> | |
148 | <listitem> | |
149 | <para> | |
150 | Specify the architecture for the container. | |
151 | </para> | |
152 | <para> | |
b9986e43 | 153 | Some valid options are |
c464fd7e SG |
154 | <option>x86</option>, |
155 | <option>i686</option>, | |
156 | <option>x86_64</option>, | |
157 | <option>amd64</option> | |
158 | </para> | |
159 | </listitem> | |
160 | </varlistentry> | |
55fc19a1 SG |
161 | </variablelist> |
162 | ||
163 | </refsect2> | |
164 | ||
165 | <refsect2> | |
166 | <title>Hostname</title> | |
167 | <para> | |
b9986e43 CB |
168 | The utsname section defines the hostname to be set for the container. |
169 | That means the container can set its own hostname without changing the | |
170 | one from the system. That makes the hostname private for the container. | |
55fc19a1 SG |
171 | </para> |
172 | <variablelist> | |
c464fd7e SG |
173 | <varlistentry> |
174 | <term> | |
b67771bc | 175 | <option>lxc.uts.name</option> |
c464fd7e SG |
176 | </term> |
177 | <listitem> | |
178 | <para> | |
179 | specify the hostname for the container | |
180 | </para> | |
181 | </listitem> | |
182 | </varlistentry> | |
55fc19a1 SG |
183 | </variablelist> |
184 | </refsect2> | |
185 | ||
186 | <refsect2> | |
187 | <title>Halt signal</title> | |
188 | <para> | |
b9986e43 CB |
189 | Allows one to specify signal name or number sent to the container's |
190 | init process to cleanly shutdown the container. Different init systems | |
191 | could use different signals to perform clean shutdown sequence. This | |
192 | option allows the signal to be specified in kill(1) fashion, e.g. | |
193 | SIGPWR, SIGRTMIN+14, SIGRTMAX-10 or plain number. The default signal is | |
194 | SIGPWR. | |
55fc19a1 SG |
195 | </para> |
196 | <variablelist> | |
936762f3 BP |
197 | <varlistentry> |
198 | <term> | |
55c84efc | 199 | <option>lxc.signal.halt</option> |
936762f3 BP |
200 | </term> |
201 | <listitem> | |
202 | <para> | |
203 | specify the signal used to halt the container | |
204 | </para> | |
205 | </listitem> | |
206 | </varlistentry> | |
207 | </variablelist> | |
208 | </refsect2> | |
209 | ||
210 | <refsect2> | |
211 | <title>Reboot signal</title> | |
212 | <para> | |
b9986e43 CB |
213 | Allows one to specify signal name or number to reboot the container. |
214 | This option allows signal to be specified in kill(1) fashion, e.g. | |
215 | SIGTERM, SIGRTMIN+14, SIGRTMAX-10 or plain number. The default signal | |
216 | is SIGINT. | |
936762f3 BP |
217 | </para> |
218 | <variablelist> | |
219 | <varlistentry> | |
220 | <term> | |
55c84efc | 221 | <option>lxc.signal.reboot</option> |
936762f3 BP |
222 | </term> |
223 | <listitem> | |
224 | <para> | |
225 | specify the signal used to reboot the container | |
226 | </para> | |
227 | </listitem> | |
228 | </varlistentry> | |
55fc19a1 SG |
229 | </variablelist> |
230 | </refsect2> | |
231 | ||
232 | <refsect2> | |
233 | <title>Stop signal</title> | |
234 | <para> | |
b9986e43 CB |
235 | Allows one to specify signal name or number to forcibly shutdown the |
236 | container. This option allows signal to be specified in kill(1) fashion, | |
237 | e.g. SIGKILL, SIGRTMIN+14, SIGRTMAX-10 or plain number. The default | |
238 | signal is SIGKILL. | |
936762f3 BP |
239 | </para> |
240 | <variablelist> | |
241 | <varlistentry> | |
242 | <term> | |
55c84efc | 243 | <option>lxc.signal.stop</option> |
936762f3 BP |
244 | </term> |
245 | <listitem> | |
246 | <para> | |
247 | specify the signal used to stop the container | |
248 | </para> | |
249 | </listitem> | |
250 | </varlistentry> | |
55fc19a1 SG |
251 | </variablelist> |
252 | </refsect2> | |
253 | ||
67c660d0 SG |
254 | <refsect2> |
255 | <title>Init command</title> | |
256 | <para> | |
257 | Sets the command to use as the init system for the containers. | |
67c660d0 | 258 | </para> |
5cda27c1 SH |
259 | <variablelist> |
260 | <varlistentry> | |
261 | <term> | |
262 | <option>lxc.execute.cmd</option> | |
263 | </term> | |
264 | <listitem> | |
265 | <para> | |
266 | Absolute path from container rootfs to the binary to run by default. This | |
fcd95ae9 | 267 | mostly makes sense for <command>lxc-execute</command>. |
5cda27c1 SH |
268 | </para> |
269 | </listitem> | |
270 | </varlistentry> | |
271 | </variablelist> | |
67c660d0 | 272 | <variablelist> |
936762f3 BP |
273 | <varlistentry> |
274 | <term> | |
9dcf7b4d | 275 | <option>lxc.init.cmd</option> |
936762f3 BP |
276 | </term> |
277 | <listitem> | |
278 | <para> | |
fcd95ae9 KY |
279 | Absolute path from container rootfs to the binary to use as init. This |
280 | mostly makes sense for <command>lxc-start</command>. Default is <command>/sbin/init</command>. | |
936762f3 BP |
281 | </para> |
282 | </listitem> | |
283 | </varlistentry> | |
67c660d0 SG |
284 | </variablelist> |
285 | </refsect2> | |
286 | ||
3c491553 L |
287 | <refsect2> |
288 | <title>Init working directory</title> | |
289 | <para> | |
290 | Sets the absolute path inside the container as the working directory for the containers. | |
291 | LXC will switch to this directory before executing init. | |
292 | </para> | |
293 | <variablelist> | |
294 | <varlistentry> | |
295 | <term> | |
296 | <option>lxc.init.cwd</option> | |
297 | </term> | |
298 | <listitem> | |
299 | <para> | |
300 | Absolute path inside the container to use as the working directory. | |
301 | </para> | |
302 | </listitem> | |
303 | </varlistentry> | |
304 | </variablelist> | |
305 | </refsect2> | |
306 | ||
dbca9237 PT |
307 | <refsect2> |
308 | <title>Init ID</title> | |
309 | <para> | |
b9986e43 | 310 | Sets the UID/GID to use for the init system, and subsequent commands. |
14a7b0f9 | 311 | Note that using a non-root UID when booting a system container will |
b9986e43 | 312 | likely not work due to missing privileges. Setting the UID/GID is mostly |
14a7b0f9 | 313 | useful when running application containers. |
dbca9237 PT |
314 | |
315 | Defaults to: UID(0), GID(0) | |
316 | </para> | |
317 | <variablelist> | |
318 | <varlistentry> | |
319 | <term> | |
9dcf7b4d | 320 | <option>lxc.init.uid</option> |
dbca9237 PT |
321 | </term> |
322 | <listitem> | |
323 | <para> | |
b9986e43 | 324 | UID to use for init. |
dbca9237 PT |
325 | </para> |
326 | </listitem> | |
327 | </varlistentry> | |
328 | <varlistentry> | |
329 | <term> | |
9dcf7b4d | 330 | <option>lxc.init.gid</option> |
dbca9237 PT |
331 | </term> |
332 | <listitem> | |
333 | <para> | |
b9986e43 | 334 | GID to use for init. |
dbca9237 PT |
335 | </para> |
336 | </listitem> | |
337 | </varlistentry> | |
338 | </variablelist> | |
339 | </refsect2> | |
340 | ||
61d7a733 YT |
341 | <refsect2> |
342 | <title>Proc</title> | |
343 | <para> | |
344 | Configure proc filesystem for the container. | |
345 | </para> | |
346 | <variablelist> | |
347 | <varlistentry> | |
348 | <term> | |
349 | <option>lxc.proc.[proc file name]</option> | |
350 | </term> | |
351 | <listitem> | |
352 | <para> | |
eb4225a0 | 353 | Specify the proc file name to be set. The file names available |
61d7a733 YT |
354 | are those listed under /proc/PID/. |
355 | Example: | |
356 | </para> | |
357 | <programlisting> | |
358 | lxc.proc.oom_score_adj = 10 | |
359 | </programlisting> | |
360 | </listitem> | |
361 | </varlistentry> | |
362 | </variablelist> | |
363 | </refsect2> | |
364 | ||
4e6eb26b CB |
365 | <refsect2> |
366 | <title>Ephemeral</title> | |
367 | <para> | |
368 | Allows one to specify whether a container will be destroyed on shutdown. | |
369 | </para> | |
370 | <variablelist> | |
371 | <varlistentry> | |
372 | <term> | |
373 | <option>lxc.ephemeral</option> | |
374 | </term> | |
375 | <listitem> | |
376 | <para> | |
377 | The only allowed values are 0 and 1. Set this to 1 to destroy a | |
d4a7da46 | 378 | container on shutdown. |
4e6eb26b CB |
379 | </para> |
380 | </listitem> | |
381 | </varlistentry> | |
382 | </variablelist> | |
383 | </refsect2> | |
384 | ||
55fc19a1 SG |
385 | <refsect2> |
386 | <title>Network</title> | |
387 | <para> | |
c464fd7e SG |
388 | The network section defines how the network is virtualized in |
389 | the container. The network virtualization acts at layer | |
390 | two. In order to use the network virtualization, parameters | |
391 | must be specified to define the network interfaces of the | |
392 | container. Several virtual interfaces can be assigned and used | |
393 | in a container even if the system has only one physical | |
394 | network interface. | |
55fc19a1 SG |
395 | </para> |
396 | <variablelist> | |
020104c3 MH |
397 | <varlistentry> |
398 | <term> | |
7fa3f2e9 | 399 | <option>lxc.net</option> |
020104c3 MH |
400 | </term> |
401 | <listitem> | |
402 | <para> | |
403 | may be used without a value to clear all previous network options. | |
404 | </para> | |
405 | </listitem> | |
406 | </varlistentry> | |
c464fd7e SG |
407 | <varlistentry> |
408 | <term> | |
7fa3f2e9 | 409 | <option>lxc.net.[i].type</option> |
c464fd7e SG |
410 | </term> |
411 | <listitem> | |
412 | <para> | |
413 | specify what kind of network virtualization to be used | |
b9986e43 CB |
414 | for the container. |
415 | Multiple networks can be specified by using an additional index | |
416 | <option>i</option> | |
7fa3f2e9 | 417 | after all <option>lxc.net.*</option> keys. For example, |
418 | <option>lxc.net.0.type = veth</option> and | |
419 | <option>lxc.net.1.type = veth</option> specify two different | |
b9986e43 CB |
420 | networks of the same type. All keys sharing the same index |
421 | <option>i</option> will be treated as belonging to the same | |
7fa3f2e9 | 422 | network. For example, <option>lxc.net.0.link = br0</option> |
423 | will belong to <option>lxc.net.0.type</option>. | |
b9986e43 | 424 | Currently, the different virtualization types can be: |
c464fd7e SG |
425 | </para> |
426 | ||
427 | <para> | |
428 | <option>none:</option> will cause the container to share | |
429 | the host's network namespace. This means the host | |
430 | network devices are usable in the container. It also | |
431 | means that if both the container and host have upstart as | |
432 | init, 'halt' in a container (for instance) will shut down the | |
e4b3e369 AK |
433 | host. Note that unprivileged containers do not work with this |
434 | setting due to an inability to mount sysfs. An unsafe workaround | |
435 | would be to bind mount the host's sysfs. | |
c464fd7e SG |
436 | </para> |
437 | ||
438 | <para> | |
439 | <option>empty:</option> will create only the loopback | |
440 | interface. | |
441 | </para> | |
442 | ||
443 | <para> | |
38005c54 MA |
444 | <option>veth:</option> a virtual ethernet pair |
445 | device is created with one side assigned to the container | |
3e5c2e69 | 446 | and the other side on the host. |
447 | <option>lxc.net.[i].veth.mode</option> specifies the | |
448 | mode the veth parent will use on the host. | |
449 | The accepted modes are <option>bridge</option> and <option>router</option>. | |
450 | The mode defaults to bridge if not specified. | |
451 | In <option>bridge</option> mode the host side is attached to a bridge specified by | |
7fa3f2e9 | 452 | the <option>lxc.net.[i].link</option> option. |
3e5c2e69 | 453 | If the bridge link is not specified, then the veth pair device |
38005c54 MA |
454 | will be created but not attached to any bridge. |
455 | Otherwise, the bridge has to be created on the system | |
456 | before starting the container. | |
457 | <command>lxc</command> won't handle any | |
458 | configuration outside of the container. | |
3e5c2e69 | 459 | In <option>router</option> mode static routes are created on the host for the |
460 | container's IP addresses pointing to the host side veth interface. | |
461 | Additionally Proxy ARP and Proxy NDP entries are added on the host side veth interface | |
462 | for the gateway IPs defined in the container to allow the container to reach the host. | |
38005c54 | 463 | By default, <command>lxc</command> chooses a name for the |
c464fd7e | 464 | network device belonging to the outside of the |
38005c54 MA |
465 | container, but if you wish to handle |
466 | this name yourselves, you can tell <command>lxc</command> | |
c464fd7e | 467 | to set a specific name with |
7fa3f2e9 | 468 | the <option>lxc.net.[i].veth.pair</option> option (except for |
c464fd7e SG |
469 | unprivileged containers where this option is ignored for security |
470 | reasons). | |
d4a7da46 | 471 | |
472 | Static routes can be added on the host pointing to the container using the | |
473 | <option>lxc.net.[i].veth.ipv4.route</option> and | |
474 | <option>lxc.net.[i].veth.ipv6.route</option> options. | |
475 | Several lines specify several routes. | |
476 | The route is in format x.y.z.t/m, eg. 192.168.1.0/24. | |
a789ca4c TP |
477 | |
478 | In <option>bridge</option> mode untagged VLAN membership can be set with the | |
479 | <option>lxc.net.[i].veth.vlan.id</option> option. It accepts a special value of 'none' indicating | |
480 | that the container port should be removed from the bridge's default untagged VLAN. | |
481 | The <option>lxc.net.[i].veth.vlan.tagged.id</option> option can be specified multiple times to set | |
482 | the container's bridge port membership to one or more tagged VLANs. | |
c464fd7e SG |
483 | </para> |
484 | ||
485 | <para> | |
486 | <option>vlan:</option> a vlan interface is linked with | |
487 | the interface specified by | |
7fa3f2e9 | 488 | the <option>lxc.net.[i].link</option> and assigned to |
c464fd7e | 489 | the container. The vlan identifier is specified with the |
7fa3f2e9 | 490 | option <option>lxc.net.[i].vlan.id</option>. |
c464fd7e SG |
491 | </para> |
492 | ||
493 | <para> | |
494 | <option>macvlan:</option> a macvlan interface is linked | |
495 | with the interface specified by | |
7fa3f2e9 | 496 | the <option>lxc.net.[i].link</option> and assigned to |
c464fd7e | 497 | the container. |
7fa3f2e9 | 498 | <option>lxc.net.[i].macvlan.mode</option> specifies the |
c464fd7e SG |
499 | mode the macvlan will use to communicate between |
500 | different macvlan on the same upper device. The accepted | |
c15ea607 EL |
501 | modes are <option>private</option>, <option>vepa</option>, |
502 | <option>bridge</option> and <option>passthru</option>. | |
c9f52382 | 503 | In <option>private</option> mode, the device never |
c15ea607 EL |
504 | communicates with any other device on the same upper_dev (default). |
505 | In <option>vepa</option> mode, the new Virtual Ethernet Port | |
c464fd7e SG |
506 | Aggregator (VEPA) mode, it assumes that the adjacent |
507 | bridge returns all frames where both source and | |
508 | destination are local to the macvlan port, i.e. the | |
509 | bridge is set up as a reflective relay. Broadcast | |
510 | frames coming in from the upper_dev get flooded to all | |
511 | macvlan interfaces in VEPA mode, local frames are not | |
c15ea607 | 512 | delivered locally. In <option>bridge</option> mode, it |
c464fd7e SG |
513 | provides the behavior of a simple bridge between |
514 | different macvlan interfaces on the same port. Frames | |
515 | from one interface to another one get delivered directly | |
516 | and are not sent out externally. Broadcast frames get | |
517 | flooded to all other bridge ports and to the external | |
518 | interface, but when they come back from a reflective | |
519 | relay, we don't deliver them again. Since we know all | |
520 | the MAC addresses, the macvlan bridge mode does not | |
c15ea607 EL |
521 | require learning or STP like the bridge module does. In |
522 | <option>passthru</option> mode, all frames received by | |
523 | the physical interface are forwarded to the macvlan | |
524 | interface. Only one macvlan interface in <option>passthru</option> | |
525 | mode is possible for one physical interface. | |
c464fd7e SG |
526 | </para> |
527 | ||
c9f52382 | 528 | <para> |
529 | <option>ipvlan:</option> an ipvlan interface is linked | |
530 | with the interface specified by | |
531 | the <option>lxc.net.[i].link</option> and assigned to | |
532 | the container. | |
533 | <option>lxc.net.[i].ipvlan.mode</option> specifies the | |
534 | mode the ipvlan will use to communicate between | |
535 | different ipvlan on the same upper device. The accepted | |
536 | modes are <option>l3</option>, <option>l3s</option> and | |
537 | <option>l2</option>. It defaults to <option>l3</option> mode. | |
538 | In <option>l3</option> mode TX processing up to L3 happens on the stack instance | |
f1d358b0 CB |
539 | attached to the dependent device and packets are switched to the stack instance of the |
540 | parent device for the L2 processing and routing from that instance will be | |
541 | used before packets are queued on the outbound device. In this mode the dependent devices | |
c9f52382 | 542 | will not receive nor can send multicast / broadcast traffic. |
543 | In <option>l3s</option> mode TX processing is very similar to the L3 mode except that | |
544 | iptables (conn-tracking) works in this mode and hence it is L3-symmetric (L3s). | |
545 | This will have slightly less performance but that shouldn't matter since you are | |
546 | choosing this mode over plain-L3 mode to make conn-tracking work. | |
547 | In <option>l2</option> mode TX processing happens on the stack instance attached to | |
f1d358b0 CB |
548 | the dependent device and packets are switched and queued to the parent device to send devices |
549 | out. In this mode the dependent devices will RX/TX multicast and broadcast (if applicable) as well. | |
c9f52382 | 550 | <option>lxc.net.[i].ipvlan.isolation</option> specifies the isolation mode. |
551 | The accepted isolation values are <option>bridge</option>, | |
552 | <option>private</option> and <option>vepa</option>. | |
553 | It defaults to <option>bridge</option>. | |
f1d358b0 CB |
554 | In <option>bridge</option> isolation mode dependent devices can cross-talk among themselves |
555 | apart from talking through the parent device. | |
c9f52382 | 556 | In <option>private</option> isolation mode the port is set in private mode. |
f1d358b0 | 557 | i.e. port won't allow cross communication between dependent devices. |
c9f52382 | 558 | In <option>vepa</option> isolation mode the port is set in VEPA mode. |
559 | i.e. port will offload switching functionality to the external entity as | |
560 | described in 802.1Qbg. | |
561 | </para> | |
562 | ||
c464fd7e SG |
563 | <para> |
564 | <option>phys:</option> an already existing interface | |
7fa3f2e9 | 565 | specified by the <option>lxc.net.[i].link</option> is |
c464fd7e SG |
566 | assigned to the container. |
567 | </para> | |
568 | </listitem> | |
569 | </varlistentry> | |
570 | ||
571 | <varlistentry> | |
572 | <term> | |
7fa3f2e9 | 573 | <option>lxc.net.[i].flags</option> |
c464fd7e SG |
574 | </term> |
575 | <listitem> | |
576 | <para> | |
b9986e43 | 577 | Specify an action to do for the network. |
c464fd7e SG |
578 | </para> |
579 | ||
580 | <para><option>up:</option> activates the interface. | |
581 | </para> | |
582 | </listitem> | |
583 | </varlistentry> | |
584 | ||
585 | <varlistentry> | |
586 | <term> | |
7fa3f2e9 | 587 | <option>lxc.net.[i].link</option> |
c464fd7e SG |
588 | </term> |
589 | <listitem> | |
590 | <para> | |
b9986e43 CB |
591 | Specify the interface to be used for real network traffic. |
592 | </para> | |
c464fd7e SG |
593 | </listitem> |
594 | </varlistentry> | |
595 | ||
6509154d | 596 | <varlistentry> |
597 | <term> | |
598 | <option>lxc.net.[i].l2proxy</option> | |
599 | </term> | |
600 | <listitem> | |
601 | <para> | |
602 | Controls whether layer 2 IP neighbour proxy entries will be added to the | |
603 | lxc.net.[i].link interface for the IP addresses of the container. | |
604 | Can be set to 0 or 1. Defaults to 0. | |
605 | When used with IPv4 addresses, the following sysctl values need to be set: | |
606 | net.ipv4.conf.[link].forwarding=1 | |
607 | When used with IPv6 addresses, the following sysctl values need to be set: | |
608 | net.ipv6.conf.[link].proxy_ndp=1 | |
609 | net.ipv6.conf.[link].forwarding=1 | |
610 | </para> | |
611 | </listitem> | |
612 | </varlistentry> | |
613 | ||
c464fd7e SG |
614 | <varlistentry> |
615 | <term> | |
7fa3f2e9 | 616 | <option>lxc.net.[i].mtu</option> |
c464fd7e SG |
617 | </term> |
618 | <listitem> | |
619 | <para> | |
b9986e43 | 620 | Specify the maximum transfer unit for this interface. |
c464fd7e SG |
621 | </para> |
622 | </listitem> | |
623 | </varlistentry> | |
624 | ||
625 | <varlistentry> | |
626 | <term> | |
7fa3f2e9 | 627 | <option>lxc.net.[i].name</option> |
c464fd7e SG |
628 | </term> |
629 | <listitem> | |
630 | <para> | |
b9986e43 CB |
631 | The interface name is dynamically allocated, but if another name |
632 | is needed because the configuration files being used by the | |
633 | container use a generic name, eg. eth0, this option will rename | |
634 | the interface in the container. | |
c464fd7e SG |
635 | </para> |
636 | </listitem> | |
637 | </varlistentry> | |
638 | ||
639 | <varlistentry> | |
640 | <term> | |
7fa3f2e9 | 641 | <option>lxc.net.[i].hwaddr</option> |
c464fd7e SG |
642 | </term> |
643 | <listitem> | |
644 | <para> | |
b9986e43 CB |
645 | The interface mac address is dynamically allocated by default to |
646 | the virtual interface, but in some cases, this is needed to | |
647 | resolve a mac address conflict or to always have the same | |
648 | link-local ipv6 address. Any "x" in address will be replaced by | |
649 | random value, this allows setting hwaddr templates. | |
c464fd7e SG |
650 | </para> |
651 | </listitem> | |
652 | </varlistentry> | |
653 | ||
654 | <varlistentry> | |
655 | <term> | |
9ff60df2 | 656 | <option>lxc.net.[i].ipv4.address</option> |
c464fd7e SG |
657 | </term> |
658 | <listitem> | |
659 | <para> | |
b9986e43 CB |
660 | Specify the ipv4 address to assign to the virtualized interface. |
661 | Several lines specify several ipv4 addresses. The address is in | |
662 | format x.y.z.t/m, eg. 192.168.1.123/24. | |
c464fd7e SG |
663 | </para> |
664 | </listitem> | |
665 | </varlistentry> | |
666 | ||
667 | <varlistentry> | |
668 | <term> | |
7fa3f2e9 | 669 | <option>lxc.net.[i].ipv4.gateway</option> |
c464fd7e SG |
670 | </term> |
671 | <listitem> | |
672 | <para> | |
b9986e43 CB |
673 | Specify the ipv4 address to use as the gateway inside the |
674 | container. The address is in format x.y.z.t, eg. 192.168.1.123. | |
c464fd7e SG |
675 | |
676 | Can also have the special value <option>auto</option>, | |
677 | which means to take the primary address from the bridge | |
678 | interface (as specified by the | |
7fa3f2e9 | 679 | <option>lxc.net.[i].link</option> option) and use that as |
c464fd7e | 680 | the gateway. <option>auto</option> is only available when |
6509154d | 681 | using the <option>veth</option>, |
c9f52382 | 682 | <option>macvlan</option> and <option>ipvlan</option> network types. |
a2f9a670 | 683 | Can also have the special value of <option>dev</option>, |
684 | which means to set the default gateway as a device route. | |
685 | This is primarily for use with layer 3 network modes, such as IPVLAN. | |
c464fd7e SG |
686 | </para> |
687 | </listitem> | |
688 | </varlistentry> | |
689 | ||
c464fd7e SG |
690 | <varlistentry> |
691 | <term> | |
2e44ae28 | 692 | <option>lxc.net.[i].ipv6.address</option> |
c464fd7e SG |
693 | </term> |
694 | <listitem> | |
695 | <para> | |
b9986e43 CB |
696 | Specify the ipv6 address to assign to the virtualized |
697 | interface. Several lines specify several ipv6 addresses. The | |
698 | address is in format x::y/m, eg. | |
699 | 2003:db8:1:0:214:1234:fe0b:3596/64 | |
c464fd7e SG |
700 | </para> |
701 | </listitem> | |
702 | </varlistentry> | |
703 | ||
704 | <varlistentry> | |
705 | <term> | |
7fa3f2e9 | 706 | <option>lxc.net.[i].ipv6.gateway</option> |
c464fd7e SG |
707 | </term> |
708 | <listitem> | |
709 | <para> | |
b9986e43 CB |
710 | Specify the ipv6 address to use as the gateway inside the |
711 | container. The address is in format x::y, eg. 2003:db8:1:0::1 | |
c464fd7e SG |
712 | |
713 | Can also have the special value <option>auto</option>, | |
714 | which means to take the primary address from the bridge | |
715 | interface (as specified by the | |
7fa3f2e9 | 716 | <option>lxc.net.[i].link</option> option) and use that as |
c464fd7e | 717 | the gateway. <option>auto</option> is only available when |
c9f52382 | 718 | using the <option>veth</option>, |
719 | <option>macvlan</option> and <option>ipvlan</option> network types. | |
a2f9a670 | 720 | Can also have the special value of <option>dev</option>, |
721 | which means to set the default gateway as a device route. | |
722 | This is primarily for use with layer 3 network modes, such as IPVLAN. | |
c464fd7e SG |
723 | </para> |
724 | </listitem> | |
725 | </varlistentry> | |
726 | ||
727 | <varlistentry> | |
728 | <term> | |
7fa3f2e9 | 729 | <option>lxc.net.[i].script.up</option> |
c464fd7e SG |
730 | </term> |
731 | <listitem> | |
732 | <para> | |
b9986e43 | 733 | Add a configuration option to specify a script to be |
c464fd7e | 734 | executed after creating and configuring the network used |
14a7b0f9 CB |
735 | from the host side. |
736 | </para> | |
737 | ||
738 | <para> | |
739 | In addition to the information available to all hooks. The | |
740 | following information is provided to the script: | |
741 | <itemizedlist> | |
742 | <listitem> | |
743 | <para> | |
744 | LXC_HOOK_TYPE: the hook type. This is either 'up' or 'down'. | |
745 | </para> | |
746 | </listitem> | |
747 | ||
748 | <listitem> | |
749 | <para> | |
750 | LXC_HOOK_SECTION: the section type 'net'. | |
751 | </para> | |
752 | </listitem> | |
753 | ||
754 | <listitem> | |
755 | <para> | |
756 | LXC_NET_TYPE: the network type. This is one of the valid | |
c9f52382 | 757 | network types listed here (e.g. 'vlan', 'macvlan', 'ipvlan', 'veth'). |
14a7b0f9 CB |
758 | </para> |
759 | </listitem> | |
760 | ||
761 | <listitem> | |
762 | <para> | |
763 | LXC_NET_PARENT: the parent device on the host. This is only | |
764 | set for network types 'mavclan', 'veth', 'phys'. | |
765 | </para> | |
766 | </listitem> | |
767 | ||
768 | <listitem> | |
769 | <para> | |
770 | LXC_NET_PEER: the name of the peer device on the host. This is | |
771 | only set for 'veth' network types. Note that this information | |
772 | is only available when <option>lxc.hook.version</option> is set | |
773 | to 1. | |
774 | </para> | |
775 | </listitem> | |
776 | </itemizedlist> | |
777 | ||
778 | Whether this information is provided in the form of environment | |
779 | variables or as arguments to the script depends on the value of | |
780 | <option>lxc.hook.version</option>. If set to 1 then information is | |
781 | provided in the form of environment variables. If set to 0 | |
782 | information is provided as arguments to the script. | |
c464fd7e | 783 | </para> |
14a7b0f9 | 784 | |
c464fd7e SG |
785 | <para> |
786 | Standard output from the script is logged at debug level. | |
787 | Standard error is not logged, but can be captured by the | |
788 | hook redirecting its standard error to standard output. | |
789 | </para> | |
790 | </listitem> | |
791 | </varlistentry> | |
792 | ||
793 | <varlistentry> | |
794 | <term> | |
7fa3f2e9 | 795 | <option>lxc.net.[i].script.down</option> |
c464fd7e SG |
796 | </term> |
797 | <listitem> | |
798 | <para> | |
b9986e43 | 799 | Add a configuration option to specify a script to be |
c464fd7e | 800 | executed before destroying the network used from the |
14a7b0f9 CB |
801 | host side. |
802 | </para> | |
803 | ||
804 | <para> | |
805 | In addition to the information available to all hooks. The | |
806 | following information is provided to the script: | |
807 | <itemizedlist> | |
808 | <listitem> | |
809 | <para> | |
810 | LXC_HOOK_TYPE: the hook type. This is either 'up' or 'down'. | |
811 | </para> | |
812 | </listitem> | |
813 | ||
814 | <listitem> | |
815 | <para> | |
816 | LXC_HOOK_SECTION: the section type 'net'. | |
817 | </para> | |
818 | </listitem> | |
819 | ||
820 | <listitem> | |
821 | <para> | |
822 | LXC_NET_TYPE: the network type. This is one of the valid | |
c9f52382 | 823 | network types listed here (e.g. 'vlan', 'macvlan', 'ipvlan', 'veth'). |
14a7b0f9 CB |
824 | </para> |
825 | </listitem> | |
826 | ||
827 | <listitem> | |
828 | <para> | |
829 | LXC_NET_PARENT: the parent device on the host. This is only | |
830 | set for network types 'mavclan', 'veth', 'phys'. | |
831 | </para> | |
832 | </listitem> | |
833 | ||
834 | <listitem> | |
835 | <para> | |
836 | LXC_NET_PEER: the name of the peer device on the host. This is | |
837 | only set for 'veth' network types. Note that this information | |
838 | is only available when <option>lxc.hook.version</option> is set | |
839 | to 1. | |
840 | </para> | |
841 | </listitem> | |
842 | </itemizedlist> | |
843 | ||
844 | Whether this information is provided in the form of environment | |
845 | variables or as arguments to the script depends on the value of | |
846 | <option>lxc.hook.version</option>. If set to 1 then information is | |
847 | provided in the form of environment variables. If set to 0 | |
848 | information is provided as arguments to the script. | |
c464fd7e | 849 | </para> |
14a7b0f9 | 850 | |
c464fd7e SG |
851 | <para> |
852 | Standard output from the script is logged at debug level. | |
853 | Standard error is not logged, but can be captured by the | |
854 | hook redirecting its standard error to standard output. | |
855 | </para> | |
856 | </listitem> | |
857 | </varlistentry> | |
55fc19a1 SG |
858 | </variablelist> |
859 | </refsect2> | |
860 | ||
861 | <refsect2> | |
862 | <title>New pseudo tty instance (devpts)</title> | |
863 | <para> | |
c464fd7e SG |
864 | For stricter isolation the container can have its own private |
865 | instance of the pseudo tty. | |
55fc19a1 SG |
866 | </para> |
867 | <variablelist> | |
c464fd7e SG |
868 | <varlistentry> |
869 | <term> | |
232763d6 | 870 | <option>lxc.pty.max</option> |
c464fd7e SG |
871 | </term> |
872 | <listitem> | |
873 | <para> | |
874 | If set, the container will have a new pseudo tty | |
875 | instance, making this private to it. The value specifies | |
55fc19a1 SG |
876 | the maximum number of pseudo ttys allowed for a pts |
877 | instance (this limitation is not implemented yet). | |
c464fd7e SG |
878 | </para> |
879 | </listitem> | |
880 | </varlistentry> | |
55fc19a1 SG |
881 | </variablelist> |
882 | </refsect2> | |
883 | ||
884 | <refsect2> | |
885 | <title>Container system console</title> | |
886 | <para> | |
c464fd7e SG |
887 | If the container is configured with a root filesystem and the |
888 | inittab file is setup to use the console, you may want to specify | |
889 | where the output of this console goes. | |
55fc19a1 SG |
890 | </para> |
891 | <variablelist> | |
28f3b1cd CB |
892 | |
893 | <varlistentry> | |
894 | <term> | |
895 | <option>lxc.console.buffer.size</option> | |
896 | </term> | |
897 | <listitem> | |
898 | <para> | |
899 | Setting this option instructs liblxc to allocate an in-memory | |
900 | ringbuffer. The container's console output will be written to the | |
901 | ringbuffer. Note that ringbuffer must be at least as big as a | |
902 | standard page size. When passed a value smaller than a single page | |
903 | size liblxc will allocate a ringbuffer of a single page size. A page | |
39ebeb72 | 904 | size is usually 4KB. |
28f3b1cd CB |
905 | |
906 | The keyword 'auto' will cause liblxc to allocate a ringbuffer of | |
39ebeb72 | 907 | 128KB. |
28f3b1cd CB |
908 | |
909 | When manually specifying a size for the ringbuffer the value should | |
910 | be a power of 2 when converted to bytes. Valid size prefixes are | |
39ebeb72 | 911 | 'KB', 'MB', 'GB'. (Note that all conversions are based on multiples |
912 | of 1024. That means 'KB' == 'KiB', 'MB' == 'MiB', 'GB' == 'GiB'. | |
6d276edc CB |
913 | Additionally, the case of the suffix is ignored, i.e. 'kB', 'KB' and |
914 | 'Kb' are treated equally.) | |
28f3b1cd CB |
915 | </para> |
916 | </listitem> | |
917 | </varlistentry> | |
918 | ||
861813e5 CB |
919 | <varlistentry> |
920 | <term> | |
921 | <option>lxc.console.size</option> | |
922 | </term> | |
923 | <listitem> | |
924 | <para> | |
925 | Setting this option instructs liblxc to place a limit on the size of | |
926 | the console log file specified in | |
927 | <option>lxc.console.logfile</option>. Note that size of the log file | |
928 | must be at least as big as a standard page size. When passed a value | |
929 | smaller than a single page size liblxc will set the size of log file | |
39ebeb72 | 930 | to a single page size. A page size is usually 4KB. |
861813e5 | 931 | |
39ebeb72 | 932 | The keyword 'auto' will cause liblxc to place a limit of 128KB on |
861813e5 CB |
933 | the log file. |
934 | ||
935 | When manually specifying a size for the log file the value should | |
936 | be a power of 2 when converted to bytes. Valid size prefixes are | |
39ebeb72 | 937 | 'KB', 'MB', 'GB'. (Note that all conversions are based on multiples |
d4a7da46 | 938 | of 1024. That means 'KB' == 'KiB', 'MB' == 'MiB', 'GB' == 'GiB'. |
6d276edc CB |
939 | Additionally, the case of the suffix is ignored, i.e. 'kB', 'KB' and |
940 | 'Kb' are treated equally.) | |
861813e5 CB |
941 | |
942 | If users want to mirror the console ringbuffer on disk they should set | |
943 | <option>lxc.console.size</option> equal to | |
944 | <option>lxc.console.buffer.size</option>. | |
945 | </para> | |
946 | </listitem> | |
947 | </varlistentry> | |
948 | ||
c464fd7e SG |
949 | <varlistentry> |
950 | <term> | |
951 | <option>lxc.console.logfile</option> | |
952 | </term> | |
953 | <listitem> | |
954 | <para> | |
d91adfa6 CB |
955 | Specify a path to a file where the console output will be written. |
956 | Note that in contrast to the on-disk ringbuffer logfile this file | |
957 | will keep growing potentially filling up the users disks if not | |
958 | rotated and deleted. This problem can also be avoided by using the | |
959 | in-memory ringbuffer options | |
960 | <option>lxc.console.buffer.size</option> and | |
961 | <option>lxc.console.buffer.logfile</option>. | |
c464fd7e SG |
962 | </para> |
963 | </listitem> | |
964 | </varlistentry> | |
d91adfa6 CB |
965 | |
966 | <varlistentry> | |
967 | <term> | |
968 | <option>lxc.console.rotate</option> | |
969 | </term> | |
970 | <listitem> | |
971 | <para> | |
972 | Whether to rotate the console logfile specified in | |
973 | <option>lxc.console.logfile</option>. Users can send an API | |
974 | request to rotate the logfile. Note that the old logfile will have | |
975 | the same name as the original with the suffix ".1" appended. | |
976 | ||
977 | Users wishing to prevent the console log file from filling the | |
978 | disk should rotate the logfile and delete it if unneeded. This | |
979 | problem can also be avoided by using the in-memory ringbuffer | |
980 | options <option>lxc.console.buffer.size</option> and | |
981 | <option>lxc.console.buffer.logfile</option>. | |
982 | </para> | |
983 | </listitem> | |
984 | </varlistentry> | |
985 | ||
c464fd7e SG |
986 | <varlistentry> |
987 | <term> | |
3aed4934 | 988 | <option>lxc.console.path</option> |
c464fd7e SG |
989 | </term> |
990 | <listitem> | |
991 | <para> | |
992 | Specify a path to a device to which the console will be | |
6e3bb289 CB |
993 | attached. The keyword 'none' will simply disable the |
994 | console. Note, when specifying 'none' and creating a device node | |
995 | for the console in the container at /dev/console or bind-mounting | |
996 | the hosts's /dev/console into the container at /dev/console the | |
997 | container will have direct access to the hosts's /dev/console. | |
998 | This is dangerous when the container has write access to the | |
999 | device and should thus be used with caution. | |
c464fd7e SG |
1000 | </para> |
1001 | </listitem> | |
1002 | </varlistentry> | |
55fc19a1 SG |
1003 | </variablelist> |
1004 | </refsect2> | |
1005 | ||
1006 | <refsect2> | |
1007 | <title>Console through the ttys</title> | |
1008 | <para> | |
c464fd7e SG |
1009 | This option is useful if the container is configured with a root |
1010 | filesystem and the inittab file is setup to launch a getty on the | |
1011 | ttys. The option specifies the number of ttys to be available for | |
1012 | the container. The number of gettys in the inittab file of the | |
1013 | container should not be greater than the number of ttys specified | |
1014 | in this option, otherwise the excess getty sessions will die and | |
1015 | respawn indefinitely giving annoying messages on the console or in | |
1016 | <filename>/var/log/messages</filename>. | |
55fc19a1 SG |
1017 | </para> |
1018 | <variablelist> | |
c464fd7e SG |
1019 | <varlistentry> |
1020 | <term> | |
fe1c5887 | 1021 | <option>lxc.tty.max</option> |
c464fd7e SG |
1022 | </term> |
1023 | <listitem> | |
1024 | <para> | |
1025 | Specify the number of tty to make available to the | |
1026 | container. | |
1027 | </para> | |
1028 | </listitem> | |
1029 | </varlistentry> | |
55fc19a1 SG |
1030 | </variablelist> |
1031 | </refsect2> | |
1032 | ||
1033 | <refsect2> | |
1034 | <title>Console devices location</title> | |
1035 | <para> | |
1036 | LXC consoles are provided through Unix98 PTYs created on the | |
c464fd7e SG |
1037 | host and bind-mounted over the expected devices in the container. |
1038 | By default, they are bind-mounted over <filename>/dev/console</filename> | |
1039 | and <filename>/dev/ttyN</filename>. This can prevent package upgrades | |
1040 | in the guest. Therefore you can specify a directory location (under | |
1041 | <filename>/dev</filename> under which LXC will create the files and | |
1042 | bind-mount over them. These will then be symbolically linked to | |
1043 | <filename>/dev/console</filename> and <filename>/dev/ttyN</filename>. | |
1044 | A package upgrade can then succeed as it is able to remove and replace | |
1045 | the symbolic links. | |
55fc19a1 SG |
1046 | </para> |
1047 | <variablelist> | |
c464fd7e SG |
1048 | <varlistentry> |
1049 | <term> | |
fe1c5887 | 1050 | <option>lxc.tty.dir</option> |
c464fd7e SG |
1051 | </term> |
1052 | <listitem> | |
1053 | <para> | |
1054 | Specify a directory under <filename>/dev</filename> | |
6e3bb289 CB |
1055 | under which to create the container console devices. Note that LXC |
1056 | will move any bind-mounts or device nodes for /dev/console into | |
1057 | this directory. | |
c464fd7e SG |
1058 | </para> |
1059 | </listitem> | |
1060 | </varlistentry> | |
55fc19a1 SG |
1061 | </variablelist> |
1062 | </refsect2> | |
1063 | ||
1064 | <refsect2> | |
1065 | <title>/dev directory</title> | |
1066 | <para> | |
c464fd7e SG |
1067 | By default, lxc creates a few symbolic links (fd,stdin,stdout,stderr) |
1068 | in the container's <filename>/dev</filename> directory but does not | |
1069 | automatically create device node entries. This allows the container's | |
1070 | <filename>/dev</filename> to be set up as needed in the container | |
1071 | rootfs. If lxc.autodev is set to 1, then after mounting the container's | |
1072 | rootfs LXC will mount a fresh tmpfs under <filename>/dev</filename> | |
63012bdd CK |
1073 | (limited to 500K by default, unless defined in lxc.autodev.tmpfs.size) |
1074 | and fill in a minimal set of initial devices. | |
55fc19a1 SG |
1075 | This is generally required when starting a container containing |
1076 | a "systemd" based "init" but may be optional at other times. Additional | |
1077 | devices in the containers /dev directory may be created through the | |
1078 | use of the <option>lxc.hook.autodev</option> hook. | |
1079 | </para> | |
1080 | <variablelist> | |
c464fd7e SG |
1081 | <varlistentry> |
1082 | <term> | |
1083 | <option>lxc.autodev</option> | |
1084 | </term> | |
1085 | <listitem> | |
1086 | <para> | |
124fa0a8 | 1087 | Set this to 0 to stop LXC from mounting and populating a minimal |
c464fd7e SG |
1088 | <filename>/dev</filename> when starting the container. |
1089 | </para> | |
1090 | </listitem> | |
1091 | </varlistentry> | |
63012bdd CK |
1092 | |
1093 | <varlistentry> | |
1094 | <term> | |
1095 | <option>lxc.autodev.tmpfs.size</option> | |
1096 | </term> | |
1097 | <listitem> | |
1098 | <para> | |
1099 | Set this to define the size of the /dev tmpfs. | |
1100 | The default value is 500000 (500K). If the parameter is used | |
1101 | but without value, the default value is used. | |
1102 | </para> | |
1103 | </listitem> | |
1104 | </varlistentry> | |
55fc19a1 | 1105 | </variablelist> |
55fc19a1 SG |
1106 | </refsect2> |
1107 | ||
1108 | <refsect2> | |
1109 | <title>Mount points</title> | |
1110 | <para> | |
c464fd7e SG |
1111 | The mount points section specifies the different places to be |
1112 | mounted. These mount points will be private to the container | |
1113 | and won't be visible by the processes running outside of the | |
1114 | container. This is useful to mount /etc, /var or /home for | |
1115 | examples. | |
55fc19a1 | 1116 | </para> |
592fd47a SH |
1117 | <para> |
1118 | NOTE - LXC will generally ensure that mount targets and relative | |
1119 | bind-mount sources are properly confined under the container | |
1120 | root, to avoid attacks involving over-mounting host directories | |
1121 | and files. (Symbolic links in absolute mount sources are ignored) | |
1122 | However, if the container configuration first mounts a directory which | |
1123 | is under the control of the container user, such as /home/joe, into | |
1124 | the container at some <filename>path</filename>, and then mounts | |
1125 | under <filename>path</filename>, then a TOCTTOU attack would be | |
1126 | possible where the container user modifies a symbolic link under | |
1127 | his home directory at just the right time. | |
1128 | </para> | |
55fc19a1 | 1129 | <variablelist> |
c464fd7e SG |
1130 | <varlistentry> |
1131 | <term> | |
47148e96 | 1132 | <option>lxc.mount.fstab</option> |
c464fd7e SG |
1133 | </term> |
1134 | <listitem> | |
1135 | <para> | |
1136 | specify a file location in | |
1137 | the <filename>fstab</filename> format, containing the | |
1138 | mount information. The mount target location can and in | |
1139 | most cases should be a relative path, which will become | |
1140 | relative to the mounted container root. For instance, | |
1141 | </para> | |
b9986e43 CB |
1142 | <programlisting> |
1143 | proc proc proc nodev,noexec,nosuid 0 0 | |
1144 | </programlisting> | |
c464fd7e SG |
1145 | <para> |
1146 | Will mount a proc filesystem under the container's /proc, | |
1147 | regardless of where the root filesystem comes from. This | |
1148 | is resilient to block device backed filesystems as well as | |
1149 | container cloning. | |
1150 | </para> | |
1151 | <para> | |
1152 | Note that when mounting a filesystem from an | |
1153 | image file or block device the third field (fs_vfstype) | |
1154 | cannot be auto as with | |
55fc19a1 | 1155 | <citerefentry> |
c464fd7e | 1156 | <refentrytitle>mount</refentrytitle> |
55fc19a1 SG |
1157 | <manvolnum>8</manvolnum> |
1158 | </citerefentry> | |
1159 | but must be explicitly specified. | |
c464fd7e SG |
1160 | </para> |
1161 | </listitem> | |
1162 | </varlistentry> | |
1163 | ||
1164 | <varlistentry> | |
1165 | <term> | |
1166 | <option>lxc.mount.entry</option> | |
1167 | </term> | |
1168 | <listitem> | |
1169 | <para> | |
d840039e | 1170 | Specify a mount point corresponding to a line in the |
c464fd7e | 1171 | fstab format. |
f5b67b36 | 1172 | |
f1d358b0 | 1173 | Moreover lxc supports mount propagation, such as rshared or |
d840039e | 1174 | rprivate, and adds three additional mount options. |
f5b67b36 NC |
1175 | <option>optional</option> don't fail if mount does not work. |
1176 | <option>create=dir</option> or <option>create=file</option> | |
1177 | to create dir (or file) when the point will be mounted. | |
181437fd YT |
1178 | <option>relative</option> source path is taken to be relative to |
1179 | the mounted container root. For instance, | |
1180 | </para> | |
767bd70a RK |
1181 | <programlisting> |
1182 | dev/null proc/kcore none bind,relative 0 0 | |
1183 | </programlisting> | |
181437fd YT |
1184 | <para> |
1185 | Will expand dev/null to ${<option>LXC_ROOTFS_MOUNT</option>}/dev/null, | |
1186 | and mount it to proc/kcore inside the container. | |
1187 | </para> | |
c464fd7e SG |
1188 | </listitem> |
1189 | </varlistentry> | |
1190 | ||
1191 | <varlistentry> | |
1192 | <term> | |
1193 | <option>lxc.mount.auto</option> | |
1194 | </term> | |
1195 | <listitem> | |
1196 | <para> | |
1197 | specify which standard kernel file systems should be | |
1198 | automatically mounted. This may dramatically simplify | |
1199 | the configuration. The file systems are: | |
1200 | </para> | |
1201 | <itemizedlist> | |
1202 | <listitem> | |
1203 | <para> | |
1204 | <option>proc:mixed</option> (or <option>proc</option>): | |
1205 | mount <filename>/proc</filename> as read-write, but | |
1206 | remount <filename>/proc/sys</filename> and | |
1207 | <filename>/proc/sysrq-trigger</filename> read-only | |
1208 | for security / container isolation purposes. | |
1209 | </para> | |
1210 | </listitem> | |
1211 | <listitem> | |
1212 | <para> | |
1213 | <option>proc:rw</option>: mount | |
1214 | <filename>/proc</filename> as read-write | |
1215 | </para> | |
1216 | </listitem> | |
1217 | <listitem> | |
1218 | <para> | |
f24a52d5 SG |
1219 | <option>sys:mixed</option> (or <option>sys</option>): |
1220 | mount <filename>/sys</filename> as read-only but with | |
1221 | /sys/devices/virtual/net writable. | |
1222 | </para> | |
1223 | </listitem> | |
1224 | <listitem> | |
1225 | <para> | |
1226 | <option>sys:ro</option>: | |
c464fd7e SG |
1227 | mount <filename>/sys</filename> as read-only |
1228 | for security / container isolation purposes. | |
1229 | </para> | |
1230 | </listitem> | |
1231 | <listitem> | |
1232 | <para> | |
1233 | <option>sys:rw</option>: mount | |
1234 | <filename>/sys</filename> as read-write | |
1235 | </para> | |
1236 | </listitem> | |
3f69fb12 | 1237 | |
c464fd7e SG |
1238 | <listitem> |
1239 | <para> | |
1240 | <option>cgroup:mixed</option>: | |
3f69fb12 SY |
1241 | Mount a tmpfs to <filename>/sys/fs/cgroup</filename>, |
1242 | create directories for all hierarchies to which the container | |
1243 | is added, create subdirectories in those hierarchies with the | |
1244 | name of the cgroup, and bind-mount the container's own cgroup | |
1245 | into that directory. The container will be able to write to | |
1246 | its own cgroup directory, but not the parents, since they will | |
1247 | be remounted read-only. | |
c464fd7e SG |
1248 | </para> |
1249 | </listitem> | |
3f69fb12 | 1250 | |
c464fd7e SG |
1251 | <listitem> |
1252 | <para> | |
3f69fb12 SY |
1253 | <option>cgroup:mixed:force</option>: |
1254 | The <option>force</option> option will cause LXC to perform | |
1255 | the cgroup mounts for the container under all circumstances. | |
1256 | Otherwise it is similar to <option>cgroup:mixed</option>. | |
1257 | This is mainly useful when the cgroup namespaces are enabled | |
1258 | where LXC will normally leave mounting cgroups to the init | |
1259 | binary of the container since it is perfectly safe to do so. | |
c464fd7e SG |
1260 | </para> |
1261 | </listitem> | |
3f69fb12 SY |
1262 | |
1263 | <listitem> | |
1264 | <para> | |
1265 | <option>cgroup:ro</option>: | |
1266 | similar to <option>cgroup:mixed</option>, but everything will | |
1267 | be mounted read-only. | |
1268 | </para> | |
1269 | </listitem> | |
1270 | ||
1271 | <listitem> | |
1272 | <para> | |
1273 | <option>cgroup:ro:force</option>: | |
1274 | The <option>force</option> option will cause LXC to perform | |
1275 | the cgroup mounts for the container under all circumstances. | |
1276 | Otherwise it is similar to <option>cgroup:ro</option>. | |
1277 | This is mainly useful when the cgroup namespaces are enabled | |
1278 | where LXC will normally leave mounting cgroups to the init | |
1279 | binary of the container since it is perfectly safe to do so. | |
1280 | </para> | |
1281 | </listitem> | |
1282 | ||
c464fd7e SG |
1283 | <listitem> |
1284 | <para> | |
1285 | <option>cgroup:rw</option>: similar to | |
3f69fb12 SY |
1286 | <option>cgroup:mixed</option>, but everything will be mounted |
1287 | read-write. Note that the paths leading up to the container's | |
1288 | own cgroup will be writable, but will not be a cgroup | |
1289 | filesystem but just part of the tmpfs of | |
1290 | <filename>/sys/fs/cgroup</filename> | |
1291 | </para> | |
1292 | </listitem> | |
1293 | ||
1294 | <listitem> | |
1295 | <para> | |
1296 | <option>cgroup:rw:force</option>: | |
1297 | The <option>force</option> option will cause LXC to perform | |
1298 | the cgroup mounts for the container under all circumstances. | |
1299 | Otherwise it is similar to <option>cgroup:rw</option>. | |
1300 | This is mainly useful when the cgroup namespaces are enabled | |
1301 | where LXC will normally leave mounting cgroups to the init | |
1302 | binary of the container since it is perfectly safe to do so. | |
c464fd7e SG |
1303 | </para> |
1304 | </listitem> | |
3f69fb12 | 1305 | |
c464fd7e SG |
1306 | <listitem> |
1307 | <para> | |
1308 | <option>cgroup</option> (without specifier): | |
1309 | defaults to <option>cgroup:rw</option> if the | |
1310 | container retains the CAP_SYS_ADMIN capability, | |
1311 | <option>cgroup:mixed</option> otherwise. | |
1312 | </para> | |
1313 | </listitem> | |
e7806b2e | 1314 | |
c464fd7e SG |
1315 | <listitem> |
1316 | <para> | |
1317 | <option>cgroup-full:mixed</option>: | |
1318 | mount a tmpfs to <filename>/sys/fs/cgroup</filename>, | |
1319 | create directories for all hierarchies to which | |
1320 | the container is added, bind-mount the hierarchies | |
1321 | from the host to the container and make everything | |
1322 | read-only except the container's own cgroup. Note | |
1323 | that compared to <option>cgroup</option>, where | |
1324 | all paths leading up to the container's own cgroup | |
1325 | are just simple directories in the underlying | |
1326 | tmpfs, here | |
1327 | <filename>/sys/fs/cgroup/$hierarchy</filename> | |
1328 | will contain the host's full cgroup hierarchy, | |
1329 | albeit read-only outside the container's own cgroup. | |
1330 | This may leak quite a bit of information into the | |
1331 | container. | |
1332 | </para> | |
1333 | </listitem> | |
e7806b2e CB |
1334 | |
1335 | <listitem> | |
1336 | <para> | |
1337 | <option>cgroup-full:mixed:force</option>: | |
1338 | The <option>force</option> option will cause LXC to perform | |
1339 | the cgroup mounts for the container under all circumstances. | |
1340 | Otherwise it is similar to <option>cgroup-full:mixed</option>. | |
1341 | This is mainly useful when the cgroup namespaces are enabled | |
1342 | where LXC will normally leave mounting cgroups to the init | |
1343 | binary of the container since it is perfectly safe to do so. | |
1344 | </para> | |
1345 | </listitem> | |
1346 | ||
c464fd7e SG |
1347 | <listitem> |
1348 | <para> | |
1349 | <option>cgroup-full:ro</option>: similar to | |
1350 | <option>cgroup-full:mixed</option>, but everything | |
1351 | will be mounted read-only. | |
1352 | </para> | |
1353 | </listitem> | |
e7806b2e CB |
1354 | |
1355 | <listitem> | |
1356 | <para> | |
1357 | <option>cgroup-full:ro:force</option>: | |
1358 | The <option>force</option> option will cause LXC to perform | |
1359 | the cgroup mounts for the container under all circumstances. | |
1360 | Otherwise it is similar to <option>cgroup-full:ro</option>. | |
1361 | This is mainly useful when the cgroup namespaces are enabled | |
1362 | where LXC will normally leave mounting cgroups to the init | |
1363 | binary of the container since it is perfectly safe to do so. | |
1364 | </para> | |
1365 | </listitem> | |
1366 | ||
c464fd7e SG |
1367 | <listitem> |
1368 | <para> | |
1369 | <option>cgroup-full:rw</option>: similar to | |
1370 | <option>cgroup-full:mixed</option>, but everything | |
1371 | will be mounted read-write. Note that in this case, | |
1372 | the container may escape its own cgroup. (Note also | |
1373 | that if the container has CAP_SYS_ADMIN support | |
1374 | and can mount the cgroup filesystem itself, it may | |
1375 | do so anyway.) | |
1376 | </para> | |
1377 | </listitem> | |
e7806b2e CB |
1378 | |
1379 | <listitem> | |
1380 | <para> | |
1381 | <option>cgroup-full:rw:force</option>: | |
1382 | The <option>force</option> option will cause LXC to perform | |
1383 | the cgroup mounts for the container under all circumstances. | |
1384 | Otherwise it is similar to <option>cgroup-full:rw</option>. | |
1385 | This is mainly useful when the cgroup namespaces are enabled | |
1386 | where LXC will normally leave mounting cgroups to the init | |
1387 | binary of the container since it is perfectly safe to do so. | |
1388 | </para> | |
1389 | </listitem> | |
1390 | ||
c464fd7e SG |
1391 | <listitem> |
1392 | <para> | |
1393 | <option>cgroup-full</option> (without specifier): | |
1394 | defaults to <option>cgroup-full:rw</option> if the | |
1395 | container retains the CAP_SYS_ADMIN capability, | |
1396 | <option>cgroup-full:mixed</option> otherwise. | |
1397 | </para> | |
1398 | </listitem> | |
e7806b2e | 1399 | |
c464fd7e | 1400 | </itemizedlist> |
4608594e SH |
1401 | <para> |
1402 | If cgroup namespaces are enabled, then any <option>cgroup</option> | |
1403 | auto-mounting request will be ignored, since the container can | |
1404 | mount the filesystems itself, and automounting can confuse the | |
1405 | container init. | |
1406 | </para> | |
c464fd7e SG |
1407 | <para> |
1408 | Note that if automatic mounting of the cgroup filesystem | |
1409 | is enabled, the tmpfs under | |
1410 | <filename>/sys/fs/cgroup</filename> will always be | |
1411 | mounted read-write (but for the <option>:mixed</option> | |
1412 | and <option>:ro</option> cases, the individual | |
1413 | hierarchies, | |
1414 | <filename>/sys/fs/cgroup/$hierarchy</filename>, will be | |
1415 | read-only). This is in order to work around a quirk in | |
1416 | Ubuntu's | |
b46f0553 | 1417 | <citerefentry> |
c464fd7e | 1418 | <refentrytitle>mountall</refentrytitle> |
b46f0553 CS |
1419 | <manvolnum>8</manvolnum> |
1420 | </citerefentry> | |
c464fd7e SG |
1421 | command that will cause containers to wait for user |
1422 | input at boot if | |
1423 | <filename>/sys/fs/cgroup</filename> is mounted read-only | |
1424 | and the container can't remount it read-write due to a | |
1425 | lack of CAP_SYS_ADMIN. | |
1426 | </para> | |
1427 | <para> | |
1428 | Examples: | |
1429 | </para> | |
1430 | <programlisting> | |
1431 | lxc.mount.auto = proc sys cgroup | |
1432 | lxc.mount.auto = proc:rw sys:rw cgroup-full:rw | |
1433 | </programlisting> | |
1434 | </listitem> | |
1435 | </varlistentry> | |
55fc19a1 SG |
1436 | |
1437 | </variablelist> | |
1438 | </refsect2> | |
1439 | ||
1440 | <refsect2> | |
1441 | <title>Root file system</title> | |
1442 | <para> | |
c464fd7e SG |
1443 | The root file system of the container can be different than that |
1444 | of the host system. | |
55fc19a1 SG |
1445 | </para> |
1446 | <variablelist> | |
c464fd7e SG |
1447 | <varlistentry> |
1448 | <term> | |
7a96a068 | 1449 | <option>lxc.rootfs.path</option> |
c464fd7e SG |
1450 | </term> |
1451 | <listitem> | |
1452 | <para> | |
1453 | specify the root file system for the container. It can | |
1454 | be an image file, a directory or a block device. If not | |
1455 | specified, the container shares its root file system | |
1456 | with the host. | |
1457 | </para> | |
1458 | <para> | |
f1c26f2c SH |
1459 | For directory or simple block-device backed containers, |
1460 | a pathname can be used. If the rootfs is backed by a nbd | |
1461 | device, then <filename>nbd:file:1</filename> specifies that | |
1462 | <filename>file</filename> should be attached to a nbd device, | |
1463 | and partition 1 should be mounted as the rootfs. | |
1464 | <filename>nbd:file</filename> specifies that the nbd device | |
1465 | itself should be mounted. <filename>overlayfs:/lower:/upper</filename> | |
1466 | specifies that the rootfs should be an overlay with <filename>/upper</filename> | |
1467 | being mounted read-write over a read-only mount of <filename>/lower</filename>. | |
12e6ab5d | 1468 | For <filename>overlay</filename> multiple <filename>/lower</filename> |
280d2379 | 1469 | directories can be specified. <filename>loop:/file</filename> tells lxc to attach |
f1c26f2c | 1470 | <filename>/file</filename> to a loop device and mount the loop device. |
c464fd7e SG |
1471 | </para> |
1472 | </listitem> | |
1473 | </varlistentry> | |
1474 | ||
1475 | <varlistentry> | |
1476 | <term> | |
1477 | <option>lxc.rootfs.mount</option> | |
1478 | </term> | |
1479 | <listitem> | |
1480 | <para> | |
7a96a068 | 1481 | where to recursively bind <option>lxc.rootfs.path</option> |
c464fd7e SG |
1482 | before pivoting. This is to ensure success of the |
1483 | <citerefentry> | |
1484 | <refentrytitle><command>pivot_root</command></refentrytitle> | |
1485 | <manvolnum>8</manvolnum> | |
1486 | </citerefentry> | |
1487 | syscall. Any directory suffices, the default should | |
1488 | generally work. | |
1489 | </para> | |
1490 | </listitem> | |
1491 | </varlistentry> | |
1492 | ||
1493 | <varlistentry> | |
1494 | <term> | |
1495 | <option>lxc.rootfs.options</option> | |
1496 | </term> | |
1497 | <listitem> | |
1498 | <para> | |
1499 | extra mount options to use when mounting the rootfs. | |
1500 | </para> | |
1501 | </listitem> | |
1502 | </varlistentry> | |
a17b1e65 | 1503 | |
e3136289 KY |
1504 | <varlistentry> |
1505 | <term> | |
1506 | <option>lxc.rootfs.managed</option> | |
1507 | </term> | |
1508 | <listitem> | |
1509 | <para> | |
1510 | Set this to 0 to indicate that LXC is not managing the | |
1511 | container storage, then LXC will not modify the | |
1512 | container storage. The default is 1. | |
1513 | </para> | |
1514 | </listitem> | |
1515 | </varlistentry> | |
1516 | ||
55fc19a1 SG |
1517 | </variablelist> |
1518 | </refsect2> | |
1519 | ||
1520 | <refsect2> | |
1521 | <title>Control group</title> | |
1522 | <para> | |
c464fd7e SG |
1523 | The control group section contains the configuration for the |
1524 | different subsystem. <command>lxc</command> does not check the | |
1525 | correctness of the subsystem name. This has the disadvantage | |
1526 | of not detecting configuration errors until the container is | |
1527 | started, but has the advantage of permitting any future | |
1528 | subsystem. | |
55fc19a1 SG |
1529 | </para> |
1530 | <variablelist> | |
c464fd7e SG |
1531 | <varlistentry> |
1532 | <term> | |
54860ed0 | 1533 | <option>lxc.cgroup.[controller name]</option> |
c464fd7e SG |
1534 | </term> |
1535 | <listitem> | |
1536 | <para> | |
54860ed0 CB |
1537 | Specify the control group value to be set on a legacy cgroup |
1538 | hierarchy. The controller name is the literal name of the control | |
1539 | group. The permitted names and the syntax of their values is not | |
1540 | dictated by LXC, instead it depends on the features of the Linux | |
1541 | kernel running at the time the container is started, eg. | |
1542 | <option>lxc.cgroup.cpuset.cpus</option> | |
1543 | </para> | |
1544 | </listitem> | |
1545 | </varlistentry> | |
1546 | <varlistentry> | |
1547 | <term> | |
1548 | <option>lxc.cgroup2.[controller name]</option> | |
1549 | </term> | |
1550 | <listitem> | |
1551 | <para> | |
1552 | Specify the control group value to be set on the unified cgroup | |
d0d68468 | 1553 | hierarchy. The controller name is the literal name of the control |
54860ed0 CB |
1554 | group. The permitted names and the syntax of their values is not |
1555 | dictated by LXC, instead it depends on the features of the Linux | |
1556 | kernel running at the time the container is started, eg. | |
1557 | <option>lxc.cgroup2.memory.high</option> | |
c464fd7e SG |
1558 | </para> |
1559 | </listitem> | |
1560 | </varlistentry> | |
bdcbb6b3 CB |
1561 | <varlistentry> |
1562 | <term> | |
1563 | <option>lxc.cgroup.dir</option> | |
1564 | </term> | |
1565 | <listitem> | |
1566 | <para> | |
1567 | specify a directory or path in which the container's cgroup will | |
1568 | be created. For example, setting | |
1569 | <option>lxc.cgroup.dir = my-cgroup/first</option> for a container | |
1570 | named "c1" will create the container's cgroup as a sub-cgroup of | |
1571 | "my-cgroup". For example, if the user's current cgroup "my-user" | |
78be8d75 | 1572 | is located in the root cgroup of the cpuset controller in a |
bdcbb6b3 CB |
1573 | cgroup v1 hierarchy this would create the cgroup |
1574 | "/sys/fs/cgroup/cpuset/my-user/my-cgroup/first/c1" for the | |
1575 | container. Any missing cgroups will be created by LXC. This | |
1576 | presupposes that the user has write access to its current cgroup. | |
1577 | </para> | |
1578 | </listitem> | |
1579 | </varlistentry> | |
a900cbaf WB |
1580 | <varlistentry> |
1581 | <term> | |
1582 | <option>lxc.cgroup.dir.container</option> | |
1583 | </term> | |
1584 | <listitem> | |
1585 | <para> | |
1586 | This is similar to <option>lxc.cgroup.dir</option>, but must be | |
1587 | used together with <option>lxc.cgroup.dir.monitor</option> and | |
1588 | affects only the container's cgroup path. This option is mutually | |
1589 | exclusive with <option>lxc.cgroup.dir</option>. | |
1590 | Note that the final path the container attaches to may be | |
1591 | extended further by the | |
51b07b70 | 1592 | <option>lxc.cgroup.dir.container.inner</option> option. |
a900cbaf WB |
1593 | </para> |
1594 | </listitem> | |
1595 | </varlistentry> | |
1596 | <varlistentry> | |
1597 | <term> | |
1598 | <option>lxc.cgroup.dir.monitor</option> | |
1599 | </term> | |
1600 | <listitem> | |
1601 | <para> | |
1602 | This is the monitor process counterpart to | |
1603 | <option>lxc.cgroup.dir.container</option>. | |
1604 | </para> | |
1605 | </listitem> | |
1606 | </varlistentry> | |
1607 | <varlistentry> | |
1608 | <term> | |
51b07b70 | 1609 | <option>lxc.cgroup.dir.container.inner</option> |
a900cbaf WB |
1610 | </term> |
1611 | <listitem> | |
1612 | <para> | |
1613 | Specify an additional subdirectory where the cgroup namespace | |
1614 | will be created. With this option, the cgroup limits will be | |
1615 | applied to the outer path specified in | |
1616 | <option>lxc.cgroup.dir.container</option>, which is not accessible | |
1617 | from within the container, making it possible to better enforce | |
1618 | limits for privileged containers in a way they cannot override | |
1619 | them. | |
1620 | This only works in conjunction with the | |
1621 | <option>lxc.cgroup.dir.container</option> and | |
1622 | <option>lxc.cgroup.dir.monitor</option> options and has otherwise | |
1623 | no effect. | |
1624 | </para> | |
1625 | </listitem> | |
1626 | </varlistentry> | |
c3b7fd80 KY |
1627 | <varlistentry> |
1628 | <term> | |
1629 | <option>lxc.cgroup.relative</option> | |
1630 | </term> | |
1631 | <listitem> | |
1632 | <para> | |
1633 | Set this to 1 to instruct LXC to never escape to the | |
1634 | root cgroup. This makes it easy for users to adhere to | |
1635 | restrictions enforced by cgroup2 and | |
1636 | systemd. Specifically, this makes it possible to run LXC | |
1637 | containers as systemd services. | |
1638 | </para> | |
1639 | </listitem> | |
1640 | </varlistentry> | |
55fc19a1 SG |
1641 | </variablelist> |
1642 | </refsect2> | |
1643 | ||
1644 | <refsect2> | |
1645 | <title>Capabilities</title> | |
1646 | <para> | |
c464fd7e SG |
1647 | The capabilities can be dropped in the container if this one |
1648 | is run as root. | |
55fc19a1 SG |
1649 | </para> |
1650 | <variablelist> | |
c464fd7e SG |
1651 | <varlistentry> |
1652 | <term> | |
1653 | <option>lxc.cap.drop</option> | |
1654 | </term> | |
1655 | <listitem> | |
1656 | <para> | |
1657 | Specify the capability to be dropped in the container. A | |
1658 | single line defining several capabilities with a space | |
1659 | separation is allowed. The format is the lower case of | |
1660 | the capability definition without the "CAP_" prefix, | |
1661 | eg. CAP_SYS_MODULE should be specified as | |
1662 | sys_module. See | |
1663 | <citerefentry> | |
1664 | <refentrytitle><command>capabilities</command></refentrytitle> | |
1665 | <manvolnum>7</manvolnum> | |
7eff30fd MH |
1666 | </citerefentry>. |
1667 | If used with no value, lxc will clear any drop capabilities | |
1668 | specified up to this point. | |
c464fd7e SG |
1669 | </para> |
1670 | </listitem> | |
1671 | </varlistentry> | |
1672 | <varlistentry> | |
1673 | <term> | |
1674 | <option>lxc.cap.keep</option> | |
1675 | </term> | |
1676 | <listitem> | |
1677 | <para> | |
1678 | Specify the capability to be kept in the container. All other | |
1679 | capabilities will be dropped. When a special value of "none" is | |
1680 | encountered, lxc will clear any keep capabilities specified up | |
1681 | to this point. A value of "none" alone can be used to drop all | |
1682 | capabilities. | |
1683 | </para> | |
1684 | </listitem> | |
1685 | </varlistentry> | |
55fc19a1 SG |
1686 | </variablelist> |
1687 | </refsect2> | |
1688 | ||
f3c9f122 | 1689 | <refsect2> |
46186acd | 1690 | <title>Namespaces</title> |
f3c9f122 | 1691 | <para> |
46186acd CB |
1692 | A namespace can be cloned (<option>lxc.namespace.clone</option>), |
1693 | kept (<option>lxc.namespace.keep</option>) or shared | |
1694 | (<option>lxc.namespace.share.[namespace identifier]</option>). | |
f3c9f122 CB |
1695 | </para> |
1696 | <variablelist> | |
46186acd CB |
1697 | <varlistentry> |
1698 | <term> | |
1699 | <option>lxc.namespace.clone</option> | |
1700 | </term> | |
1701 | <listitem> | |
1702 | <para> | |
1703 | Specify namespaces which the container is supposed to be created | |
1704 | with. The namespaces to create are specified as a space separated | |
1705 | list. Each namespace must correspond to one of the standard | |
1706 | namespace identifiers as seen in the | |
1707 | <filename>/proc/PID/ns</filename> directory. | |
1708 | When <option>lxc.namespace.clone</option> is not explicitly set all | |
1709 | namespaces supported by the kernel and the current configuration | |
1710 | will be used. | |
1711 | </para> | |
1712 | ||
1713 | <para> | |
1714 | To create a new mount, net and ipc namespace set | |
1715 | <option>lxc.namespace.clone=mount net ipc</option>. | |
1716 | </para> | |
1717 | </listitem> | |
1718 | </varlistentry> | |
1719 | ||
1720 | <varlistentry> | |
1721 | <term> | |
1722 | <option>lxc.namespace.keep</option> | |
1723 | </term> | |
1724 | <listitem> | |
1725 | <para> | |
1726 | Specify namespaces which the container is supposed to inherit from | |
1727 | the process that created it. The namespaces to keep are specified as | |
1728 | a space separated list. Each namespace must correspond to one of the | |
1729 | standard namespace identifiers as seen in the | |
1730 | <filename>/proc/PID/ns</filename> directory. | |
1731 | The <option>lxc.namespace.keep</option> is a | |
1732 | blacklist option, i.e. it is useful when enforcing that containers | |
1733 | must keep a specific set of namespaces. | |
1734 | </para> | |
1735 | ||
1736 | <para> | |
1737 | To keep the network, user and ipc namespace set | |
1738 | <option>lxc.namespace.keep=user net ipc</option>. | |
1739 | </para> | |
1740 | ||
1741 | <para> | |
1742 | Note that sharing pid namespaces will likely not work with most init | |
1743 | systems. | |
1744 | </para> | |
1745 | ||
1746 | <para> | |
1747 | Note that if the container requests a new user namespace and the | |
1748 | container wants to inherit the network namespace it needs to inherit | |
1749 | the user namespace as well. | |
1750 | </para> | |
1751 | </listitem> | |
1752 | </varlistentry> | |
1753 | ||
f3c9f122 CB |
1754 | <varlistentry> |
1755 | <term> | |
b074bbf1 | 1756 | <option>lxc.namespace.share.[namespace identifier]</option> |
f3c9f122 CB |
1757 | </term> |
1758 | <listitem> | |
1759 | <para> | |
1760 | Specify a namespace to inherit from another container or process. | |
1761 | The <option>[namespace identifier]</option> suffix needs to be | |
1762 | replaced with one of the namespaces that appear in the | |
1763 | <filename>/proc/PID/ns</filename> directory. | |
1764 | </para> | |
1765 | ||
1766 | <para> | |
1767 | To inherit the namespace from another process set the | |
b074bbf1 CB |
1768 | <option>lxc.namespace.share.[namespace identifier]</option> to the PID of |
1769 | the process, e.g. <option>lxc.namespace.share.net=42</option>. | |
f3c9f122 CB |
1770 | </para> |
1771 | ||
1772 | <para> | |
d4a7da46 | 1773 | To inherit the namespace from another container set the |
b074bbf1 CB |
1774 | <option>lxc.namespace.share.[namespace identifier]</option> to the name of |
1775 | the container, e.g. <option>lxc.namespace.share.pid=c3</option>. | |
f3c9f122 CB |
1776 | </para> |
1777 | ||
1778 | <para> | |
1779 | To inherit the namespace from another container located in a | |
1780 | different path than the standard liblxc path set the | |
b074bbf1 | 1781 | <option>lxc.namespace.share.[namespace identifier]</option> to the full |
f3c9f122 | 1782 | path to the container, e.g. |
b074bbf1 | 1783 | <option>lxc.namespace.share.user=/opt/c3</option>. |
f3c9f122 CB |
1784 | </para> |
1785 | ||
1786 | <para> | |
1787 | In order to inherit namespaces the caller needs to have sufficient | |
1788 | privilege over the process or container. | |
1789 | </para> | |
1790 | ||
1791 | <para> | |
1792 | Note that sharing pid namespaces between system containers will | |
1793 | likely not work with most init systems. | |
1794 | </para> | |
1795 | ||
1796 | <para> | |
1797 | Note that if two processes are in different user namespaces and one | |
1798 | process wants to inherit the other's network namespace it usually | |
1799 | needs to inherit the user namespace as well. | |
1800 | </para> | |
8de90384 TA |
1801 | |
1802 | <para> | |
1803 | Note that without careful additional configuration of an LSM, | |
1804 | sharing user+pid namespaces with a task may allow that task to | |
1805 | escalate privileges to that of the task calling liblxc. | |
1806 | </para> | |
f3c9f122 CB |
1807 | </listitem> |
1808 | </varlistentry> | |
7fb5a8df CB |
1809 | |
1810 | <varlistentry> | |
1811 | <term> | |
1812 | <option>lxc.time.offset.boot</option> | |
1813 | </term> | |
1814 | <listitem> | |
1815 | <para> | |
1816 | Specify a positive or negative offset for the boottime clock. The | |
1817 | format accepts hours (h), minutes (m), seconds (s), | |
1818 | milliseconds (ms), microseconds (us), and nanoseconds (ns). | |
1819 | </para> | |
1820 | </listitem> | |
1821 | </varlistentry> | |
1822 | ||
1823 | <varlistentry> | |
1824 | <term> | |
1825 | <option>lxc.time.offset.monotonic</option> | |
1826 | </term> | |
1827 | <listitem> | |
1828 | <para> | |
bb144af2 | 1829 | Specify a positive or negative offset for the monotonic clock. The |
7fb5a8df CB |
1830 | format accepts hours (h), minutes (m), seconds (s), |
1831 | milliseconds (ms), microseconds (us), and nanoseconds (ns). | |
1832 | </para> | |
1833 | </listitem> | |
1834 | </varlistentry> | |
1835 | ||
f3c9f122 CB |
1836 | </variablelist> |
1837 | </refsect2> | |
1838 | ||
93f9e90d WB |
1839 | <refsect2> |
1840 | <title>Resource limits</title> | |
1841 | <para> | |
1842 | The soft and hard resource limits for the container can be changed. | |
1843 | Unprivileged containers can only lower them. Resources which are not | |
1844 | explicitly specified will be inherited. | |
1845 | </para> | |
1846 | <variablelist> | |
1847 | <varlistentry> | |
1848 | <term> | |
240d4b74 | 1849 | <option>lxc.prlimit.[limit name]</option> |
93f9e90d WB |
1850 | </term> |
1851 | <listitem> | |
1852 | <para> | |
1853 | Specify the resource limit to be set. A limit is specified as two | |
1854 | colon separated values which are either numeric or the word | |
1855 | 'unlimited'. A single value can be used as a shortcut to set both | |
1856 | soft and hard limit to the same value. The permitted names the | |
1857 | "RLIMIT_" resource names in lowercase without the "RLIMIT_" | |
1858 | prefix, eg. RLIMIT_NOFILE should be specified as "nofile". See | |
1859 | <citerefentry> | |
1860 | <refentrytitle><command>setrlimit</command></refentrytitle> | |
1861 | <manvolnum>2</manvolnum> | |
1862 | </citerefentry>. | |
1863 | If used with no value, lxc will clear the resource limit | |
1864 | specified up to this point. A resource with no explicitly | |
1865 | configured limitation will be inherited from the process starting | |
1866 | up the container. | |
1867 | </para> | |
1868 | </listitem> | |
1869 | </varlistentry> | |
1870 | </variablelist> | |
1871 | </refsect2> | |
1872 | ||
7edd0540 L |
1873 | <refsect2> |
1874 | <title>Sysctl</title> | |
1875 | <para> | |
1876 | Configure kernel parameters for the container. | |
1877 | </para> | |
1878 | <variablelist> | |
1879 | <varlistentry> | |
1880 | <term> | |
1881 | <option>lxc.sysctl.[kernel parameters name]</option> | |
1882 | </term> | |
1883 | <listitem> | |
1884 | <para> | |
d4a7da46 | 1885 | Specify the kernel parameters to be set. The parameters available |
7edd0540 | 1886 | are those listed under /proc/sys/. |
e409b214 | 1887 | Note that not all sysctls are namespaced. Changing Non-namespaced |
7edd0540 L |
1888 | sysctls will cause the system-wide setting to be modified. |
1889 | <citerefentry> | |
1890 | <refentrytitle><command>sysctl</command></refentrytitle> | |
1891 | <manvolnum>8</manvolnum> | |
1892 | </citerefentry>. | |
d4a7da46 | 1893 | If used with no value, lxc will clear the parameters specified up |
7edd0540 L |
1894 | to this point. |
1895 | </para> | |
1896 | </listitem> | |
1897 | </varlistentry> | |
1898 | </variablelist> | |
1899 | </refsect2> | |
1900 | ||
55fc19a1 SG |
1901 | <refsect2> |
1902 | <title>Apparmor profile</title> | |
1903 | <para> | |
c464fd7e SG |
1904 | If lxc was compiled and installed with apparmor support, and the host |
1905 | system has apparmor enabled, then the apparmor profile under which the | |
1906 | container should be run can be specified in the container | |
7a126ae1 SH |
1907 | configuration. The default is <command>lxc-container-default-cgns</command> |
1908 | if the host kernel is cgroup namespace aware, or | |
69e3b3be | 1909 | <command>lxc-container-default</command> otherwise. |
55fc19a1 SG |
1910 | </para> |
1911 | <variablelist> | |
c464fd7e SG |
1912 | <varlistentry> |
1913 | <term> | |
a1d5fdfd | 1914 | <option>lxc.apparmor.profile</option> |
c464fd7e SG |
1915 | </term> |
1916 | <listitem> | |
1917 | <para> | |
1918 | Specify the apparmor profile under which the container should | |
1919 | be run. To specify that the container should be unconfined, | |
1920 | use | |
1921 | </para> | |
a1d5fdfd | 1922 | <programlisting>lxc.apparmor.profile = unconfined</programlisting> |
7a126ae1 SH |
1923 | <para> |
1924 | If the apparmor profile should remain unchanged (i.e. if you | |
1925 | are nesting containers and are already confined), then use | |
1926 | </para> | |
a1d5fdfd | 1927 | <programlisting>lxc.apparmor.profile = unchanged</programlisting> |
8dca2bd3 KY |
1928 | <para> |
1929 | If you instruct LXC to generate the apparmor profile, | |
1930 | then use | |
1931 | </para> | |
1932 | <programlisting>lxc.apparmor.profile = generated</programlisting> | |
c464fd7e SG |
1933 | </listitem> |
1934 | </varlistentry> | |
1935 | <varlistentry> | |
1936 | <term> | |
69e38e00 | 1937 | <option>lxc.apparmor.allow_incomplete</option> |
c464fd7e SG |
1938 | </term> |
1939 | <listitem> | |
1940 | <para> | |
1941 | Apparmor profiles are pathname based. Therefore many file | |
1942 | restrictions require mount restrictions to be effective against | |
1943 | a determined attacker. However, these mount restrictions are not | |
1944 | yet implemented in the upstream kernel. Without the mount | |
1945 | restrictions, the apparmor profiles still protect against accidental | |
1946 | damager. | |
1947 | </para> | |
1948 | <para> | |
1949 | If this flag is 0 (default), then the container will not be | |
1950 | started if the kernel lacks the apparmor mount features, so that a | |
1951 | regression after a kernel upgrade will be detected. To start the | |
1952 | container under partial apparmor protection, set this flag to 1. | |
1953 | </para> | |
1954 | </listitem> | |
1955 | </varlistentry> | |
8dca2bd3 KY |
1956 | |
1957 | <varlistentry> | |
1958 | <term> | |
1959 | <option>lxc.apparmor.allow_nesting</option> | |
1960 | </term> | |
1961 | <listitem> | |
1962 | <para> | |
1963 | If set this to 1, causes the following changes. When | |
1964 | generated apparmor profiles are used, they will contain | |
1965 | the necessary changes to allow creating a nested | |
1966 | container. In addition to the usual mount points, | |
1967 | <filename>/dev/.lxc/proc</filename> | |
1968 | and <filename>/dev/.lxc/sys</filename> will contain | |
1969 | procfs and sysfs mount points without the lxcfs | |
1970 | overlays, which, if generated apparmor profiles are | |
1971 | being used, will not be read/writable directly. | |
1972 | </para> | |
1973 | </listitem> | |
1974 | </varlistentry> | |
1975 | ||
1976 | <varlistentry> | |
1977 | <term> | |
1978 | <option>lxc.apparmor.raw</option> | |
1979 | </term> | |
1980 | <listitem> | |
1981 | <para> | |
1982 | A list of raw AppArmor profile lines to append to the | |
1983 | profile. Only valid when using generated profiles. | |
1984 | </para> | |
1985 | </listitem> | |
1986 | </varlistentry> | |
1987 | ||
55fc19a1 SG |
1988 | </variablelist> |
1989 | </refsect2> | |
1990 | ||
1991 | <refsect2> | |
1992 | <title>SELinux context</title> | |
1993 | <para> | |
c464fd7e SG |
1994 | If lxc was compiled and installed with SELinux support, and the host |
1995 | system has SELinux enabled, then the SELinux context under which the | |
1996 | container should be run can be specified in the container | |
1997 | configuration. The default is <command>unconfined_t</command>, | |
1998 | which means that lxc will not attempt to change contexts. | |
1999 | See @DATADIR@/lxc/selinux/lxc.te for an example policy and more | |
2000 | information. | |
55fc19a1 SG |
2001 | </para> |
2002 | <variablelist> | |
c464fd7e SG |
2003 | <varlistentry> |
2004 | <term> | |
b84702ab | 2005 | <option>lxc.selinux.context</option> |
c464fd7e SG |
2006 | </term> |
2007 | <listitem> | |
2008 | <para> | |
2009 | Specify the SELinux context under which the container should | |
2010 | be run or <command>unconfined_t</command>. For example | |
2011 | </para> | |
b84702ab | 2012 | <programlisting>lxc.selinux.context = system_u:system_r:lxc_t:s0:c22</programlisting> |
c464fd7e SG |
2013 | </listitem> |
2014 | </varlistentry> | |
ad36e96a MB |
2015 | <varlistentry> |
2016 | <term> | |
2017 | <option>lxc.selinux.context.keyring</option> | |
2018 | </term> | |
2019 | <listitem> | |
2020 | <para> | |
2021 | Specify the SELinux context under which the container's keyring | |
2022 | should be created. By default this the same as lxc.selinux.context, or | |
48e3c95a | 2023 | the context lxc is executed under if lxc.selinux.context has not been set. |
ad36e96a MB |
2024 | </para> |
2025 | <programlisting>lxc.selinux.context.keyring = system_u:system_r:lxc_t:s0:c22</programlisting> | |
2026 | </listitem> | |
2027 | </varlistentry> | |
2028 | </variablelist> | |
2029 | </refsect2> | |
2030 | ||
2031 | <refsect2> | |
2032 | <title>Kernel Keyring</title> | |
2033 | <para> | |
2034 | The Linux Keyring facility is primarily a way for various | |
2035 | kernel components to retain or cache security data, authentication | |
2036 | keys, encryption keys, and other data in the kernel. By default lxc | |
2037 | will create a new session keyring for the started application. | |
2038 | </para> | |
2039 | <variablelist> | |
2040 | <varlistentry> | |
2041 | <term> | |
2042 | <option>lxc.keyring.session</option> | |
2043 | </term> | |
2044 | <listitem> | |
2045 | <para> | |
2046 | Disable the creation of new session keyring by lxc. The started | |
2047 | application will then inherit the current session keyring. | |
2048 | By default, or when passing the value 1, a new keyring will be created. | |
2049 | </para> | |
2050 | <programlisting>lxc.keyring.session = 0</programlisting> | |
2051 | </listitem> | |
2052 | </varlistentry> | |
55fc19a1 SG |
2053 | </variablelist> |
2054 | </refsect2> | |
2055 | ||
2056 | <refsect2> | |
2057 | <title>Seccomp configuration</title> | |
2058 | <para> | |
2059 | A container can be started with a reduced set of available | |
c464fd7e SG |
2060 | system calls by loading a seccomp profile at startup. The |
2061 | seccomp configuration file must begin with a version number | |
2062 | on the first line, a policy type on the second line, followed | |
2063 | by the configuration. | |
55fc19a1 | 2064 | </para> |
a7c27357 SH |
2065 | <para> |
2066 | Versions 1 and 2 are currently supported. In version 1, the | |
c464fd7e SG |
2067 | policy is a simple whitelist. The second line therefore must |
2068 | read "whitelist", with the rest of the file containing one (numeric) | |
8927207b | 2069 | syscall number per line. Each syscall number is whitelisted, |
c464fd7e | 2070 | while every unlisted number is blacklisted for use in the container |
a7c27357 SH |
2071 | </para> |
2072 | ||
2073 | <para> | |
2074 | In version 2, the policy may be blacklist or whitelist, | |
2075 | supports per-rule and per-policy default actions, and supports | |
2076 | per-architecture system call resolution from textual names. | |
2077 | </para> | |
2078 | <para> | |
2079 | An example blacklist policy, in which all system calls are | |
2080 | allowed except for mknod, which will simply do nothing and | |
2081 | return 0 (success), looks like: | |
2082 | </para> | |
b9986e43 CB |
2083 | |
2084 | <programlisting> | |
2085 | 2 | |
2086 | blacklist | |
2087 | mknod errno 0 | |
8a643759 | 2088 | ioctl notify |
b9986e43 CB |
2089 | </programlisting> |
2090 | ||
8a643759 CB |
2091 | <para> |
2092 | Specifying "errno" as action will cause LXC to register a seccomp filter | |
7dd6ead9 | 2093 | that will cause a specific errno to be returned to the caller. The errno |
8a643759 CB |
2094 | value can be specified after the "errno" action word. |
2095 | </para> | |
2096 | ||
2097 | <para> | |
2098 | Specifying "notify" as action will cause LXC to register a seccomp | |
2099 | listener and retrieve a listener file descriptor from the kernel. When a | |
2100 | syscall is made that is registered as "notify" the kernel will generate a | |
2101 | poll event and send a message over the file descriptor. The caller can | |
2102 | read this message, inspect the syscalls including its arguments. Based on | |
2103 | this information the caller is expected to send back a message informing | |
2104 | the kernel which action to take. Until that message is sent the kernel | |
2105 | will block the calling process. The format of the messages to read and | |
2106 | sent is documented in seccomp itself. | |
2107 | </para> | |
2108 | ||
55fc19a1 | 2109 | <variablelist> |
c464fd7e SG |
2110 | <varlistentry> |
2111 | <term> | |
0b427da0 | 2112 | <option>lxc.seccomp.profile</option> |
c464fd7e SG |
2113 | </term> |
2114 | <listitem> | |
2115 | <para> | |
2116 | Specify a file containing the seccomp configuration to | |
2117 | load before the container starts. | |
2118 | </para> | |
2119 | </listitem> | |
2120 | </varlistentry> | |
50d86993 CB |
2121 | <varlistentry> |
2122 | <term> | |
2123 | <option>lxc.seccomp.allow_nesting</option> | |
2124 | </term> | |
2125 | <listitem> | |
2126 | <para> | |
2127 | If this flag is set to 1, then seccomp filters will be stacked | |
2128 | regardless of whether a seccomp profile is already loaded. | |
2129 | This allows nested containers to load their own seccomp profile. | |
2130 | The default setting is 0. | |
2131 | </para> | |
2132 | </listitem> | |
2133 | </varlistentry> | |
8a643759 CB |
2134 | <varlistentry> |
2135 | <term> | |
2136 | <option>lxc.seccomp.notify.proxy</option> | |
2137 | </term> | |
2138 | <listitem> | |
2139 | <para> | |
2140 | Specify a unix socket to which LXC will connect and forward | |
214008ee | 2141 | seccomp events to. The path must be in the form |
8a643759 CB |
2142 | unix:/path/to/socket or unix:@socket. The former specifies a |
2143 | path-bound unix domain socket while the latter specifies an | |
2144 | abstract unix domain socket. | |
214008ee WB |
2145 | </para> |
2146 | </listitem> | |
2147 | </varlistentry> | |
2148 | <varlistentry> | |
2149 | <term> | |
2150 | <option>lxc.seccomp.notify.cookie</option> | |
2151 | </term> | |
2152 | <listitem> | |
2153 | <para> | |
2154 | An additional string sent along with proxied seccomp notification | |
2155 | requests. | |
2156 | </para> | |
8a643759 CB |
2157 | </listitem> |
2158 | </varlistentry> | |
55fc19a1 SG |
2159 | </variablelist> |
2160 | </refsect2> | |
2161 | ||
222ddc91 CB |
2162 | <refsect2> |
2163 | <title>PR_SET_NO_NEW_PRIVS</title> | |
2164 | <para> | |
2165 | With PR_SET_NO_NEW_PRIVS active execve() promises not to grant | |
2166 | privileges to do anything that could not have been done without | |
2167 | the execve() call (for example, rendering the set-user-ID and | |
2168 | set-group-ID mode bits, and file capabilities non-functional). | |
2169 | Once set, this bit cannot be unset. The setting of this bit is | |
2170 | inherited by children created by fork() and clone(), and preserved | |
2171 | across execve(). | |
2172 | Note that PR_SET_NO_NEW_PRIVS is applied after the container has | |
2173 | changed into its intended AppArmor profile or SElinux context. | |
2174 | </para> | |
2175 | <variablelist> | |
2176 | <varlistentry> | |
2177 | <term> | |
2178 | <option>lxc.no_new_privs</option> | |
2179 | </term> | |
2180 | <listitem> | |
2181 | <para> | |
2182 | Specify whether the PR_SET_NO_NEW_PRIVS flag should be set for the | |
2183 | container. Set to 1 to activate. | |
2184 | </para> | |
2185 | </listitem> | |
2186 | </varlistentry> | |
2187 | </variablelist> | |
2188 | </refsect2> | |
2189 | ||
55fc19a1 SG |
2190 | <refsect2> |
2191 | <title>UID mappings</title> | |
2192 | <para> | |
2193 | A container can be started in a private user namespace with | |
c464fd7e SG |
2194 | user and group id mappings. For instance, you can map userid |
2195 | 0 in the container to userid 200000 on the host. The root | |
2196 | user in the container will be privileged in the container, | |
2197 | but unprivileged on the host. Normally a system container | |
2198 | will want a range of ids, so you would map, for instance, | |
2199 | user and group ids 0 through 20,000 in the container to the | |
2200 | ids 200,000 through 220,000. | |
55fc19a1 SG |
2201 | </para> |
2202 | <variablelist> | |
c464fd7e SG |
2203 | <varlistentry> |
2204 | <term> | |
bdcbb6b3 | 2205 | <option>lxc.idmap</option> |
c464fd7e SG |
2206 | </term> |
2207 | <listitem> | |
2208 | <para> | |
2209 | Four values must be provided. First a character, either | |
2210 | 'u', or 'g', to specify whether user or group ids are | |
2211 | being mapped. Next is the first userid as seen in the | |
2212 | user namespace of the container. Next is the userid as | |
2213 | seen on the host. Finally, a range indicating the number | |
2214 | of consecutive ids to map. | |
2215 | </para> | |
2216 | </listitem> | |
2217 | </varlistentry> | |
55fc19a1 SG |
2218 | </variablelist> |
2219 | </refsect2> | |
2220 | ||
2221 | <refsect2> | |
2222 | <title>Container hooks</title> | |
2223 | <para> | |
2224 | Container hooks are programs or scripts which can be executed | |
c464fd7e | 2225 | at various times in a container's lifetime. |
55fc19a1 SG |
2226 | </para> |
2227 | <para> | |
44ae0fb6 CB |
2228 | When a container hook is executed, additional information is passed |
2229 | along. The <option>lxc.hook.version</option> argument can be used to | |
2230 | determine if the following arguments are passed as command line | |
2231 | arguments or through environment variables. The arguments are: | |
c464fd7e SG |
2232 | <itemizedlist> |
2233 | <listitem><para> Container name. </para></listitem> | |
2234 | <listitem><para> Section (always 'lxc'). </para></listitem> | |
2235 | <listitem><para> The hook type (i.e. 'clone' or 'pre-mount'). </para></listitem> | |
0a2b5ab1 | 2236 | <listitem><para> Additional arguments. In the |
a9145d62 CB |
2237 | case of the clone hook, any extra arguments passed will appear as |
2238 | further arguments to the hook. In the case of the stop hook, paths to | |
2239 | filedescriptors for each of the container's namespaces along with | |
2240 | their types are passed. </para></listitem> | |
c464fd7e SG |
2241 | </itemizedlist> |
2242 | The following environment variables are set: | |
2243 | <itemizedlist> | |
44ae0fb6 CB |
2244 | <listitem><para> LXC_CGNS_AWARE: indicator whether the container is |
2245 | cgroup namespace aware. </para></listitem> | |
2246 | <listitem><para> LXC_CONFIG_FILE: the path to the container | |
2247 | configuration file. </para></listitem> | |
2248 | <listitem><para> LXC_HOOK_TYPE: the hook type (e.g. 'clone', 'mount', | |
2249 | 'pre-mount'). Note that the existence of this environment variable is | |
2250 | conditional on the value of <option>lxc.hook.version</option>. If it | |
2251 | is set to 1 then LXC_HOOK_TYPE will be set. | |
2252 | </para></listitem> | |
2253 | <listitem><para> LXC_HOOK_SECTION: the section type (e.g. 'lxc', | |
2254 | 'net'). Note that the existence of this environment variable is | |
2255 | conditional on the value of <option>lxc.hook.version</option>. If it | |
2256 | is set to 1 then LXC_HOOK_SECTION will be set. | |
2257 | </para></listitem> | |
a2c09be0 CB |
2258 | <listitem><para> LXC_HOOK_VERSION: the version of the hooks. This |
2259 | value is identical to the value of the container's | |
2260 | <option>lxc.hook.version</option> config item. If it is set to 0 then | |
2261 | old-style hooks are used. If it is set to 1 then new-style hooks are | |
2262 | used. </para></listitem> | |
44ae0fb6 | 2263 | <listitem><para> LXC_LOG_LEVEL: the container's log level. </para></listitem> |
c464fd7e | 2264 | <listitem><para> LXC_NAME: is the container's name. </para></listitem> |
18b3b9c1 CB |
2265 | <listitem><para> LXC_[NAMESPACE IDENTIFIER]_NS: path under |
2266 | /proc/PID/fd/ to a file descriptor referring to the container's | |
2267 | namespace. For each preserved namespace type there will be a separate | |
2268 | environment variable. These environment variables will only be set if | |
2269 | <option>lxc.hook.version</option> is set to 1. </para></listitem> | |
c464fd7e | 2270 | <listitem><para> LXC_ROOTFS_MOUNT: the path to the mounted root filesystem. </para></listitem> |
44ae0fb6 CB |
2271 | <listitem><para> LXC_ROOTFS_PATH: this is the lxc.rootfs.path entry |
2272 | for the container. Note this is likely not where the mounted rootfs is | |
2273 | to be found, use LXC_ROOTFS_MOUNT for that. </para></listitem> | |
2274 | <listitem><para> LXC_SRC_NAME: in the case of the clone hook, this is | |
2275 | the original container's name. </para></listitem> | |
c464fd7e | 2276 | </itemizedlist> |
55fc19a1 SG |
2277 | </para> |
2278 | <para> | |
2279 | Standard output from the hooks is logged at debug level. | |
2280 | Standard error is not logged, but can be captured by the | |
2281 | hook redirecting its standard error to standard output. | |
2282 | </para> | |
2283 | <variablelist> | |
44ae0fb6 CB |
2284 | <varlistentry> |
2285 | <term> | |
2286 | <option>lxc.hook.version</option> | |
2287 | </term> | |
2288 | <listitem> | |
2289 | <para> | |
2290 | To pass the arguments in new style via environment variables set to | |
2291 | 1 otherwise set to 0 to pass them as arguments. | |
2292 | This setting affects all hooks arguments that were traditionally | |
2293 | passed as arguments to the script. Specifically, it affects the | |
2294 | container name, section (e.g. 'lxc', 'net') and hook type (e.g. | |
2295 | 'clone', 'mount', 'pre-mount') arguments. If new-style hooks are | |
2296 | used then the arguments will be available as environment variables. | |
2297 | The container name will be set in LXC_NAME. (This is set | |
2298 | independently of the value used for this config item.) The section | |
2299 | will be set in LXC_HOOK_SECTION and the hook type will be set in | |
2300 | LXC_HOOK_TYPE. | |
18b3b9c1 CB |
2301 | It also affects how the paths to file descriptors referring to the |
2302 | container's namespaces are passed. If set to 1 then for each | |
2303 | namespace a separate environment variable LXC_[NAMESPACE | |
2304 | IDENTIFIER]_NS will be set. If set to 0 then the paths will be | |
2305 | passed as arguments to the stop hook. | |
44ae0fb6 CB |
2306 | </para> |
2307 | </listitem> | |
2308 | </varlistentry> | |
2309 | </variablelist> | |
2310 | <variablelist> | |
c464fd7e SG |
2311 | <varlistentry> |
2312 | <term> | |
2313 | <option>lxc.hook.pre-start</option> | |
2314 | </term> | |
2315 | <listitem> | |
2316 | <para> | |
2317 | A hook to be run in the host's namespace before the | |
2318 | container ttys, consoles, or mounts are up. | |
2319 | </para> | |
2320 | </listitem> | |
2321 | </varlistentry> | |
55fc19a1 SG |
2322 | </variablelist> |
2323 | <variablelist> | |
c464fd7e SG |
2324 | <varlistentry> |
2325 | <term> | |
2326 | <option>lxc.hook.pre-mount</option> | |
2327 | </term> | |
2328 | <listitem> | |
2329 | <para> | |
2330 | A hook to be run in the container's fs namespace but before | |
2331 | the rootfs has been set up. This allows for manipulation | |
2332 | of the rootfs, i.e. to mount an encrypted filesystem. Mounts | |
2333 | done in this hook will not be reflected on the host (apart from | |
2334 | mounts propagation), so they will be automatically cleaned up | |
2335 | when the container shuts down. | |
2336 | </para> | |
2337 | </listitem> | |
2338 | </varlistentry> | |
55fc19a1 SG |
2339 | </variablelist> |
2340 | <variablelist> | |
c464fd7e SG |
2341 | <varlistentry> |
2342 | <term> | |
2343 | <option>lxc.hook.mount</option> | |
2344 | </term> | |
2345 | <listitem> | |
2346 | <para> | |
2347 | A hook to be run in the container's namespace after | |
2348 | mounting has been done, but before the pivot_root. | |
2349 | </para> | |
2350 | </listitem> | |
2351 | </varlistentry> | |
55fc19a1 SG |
2352 | </variablelist> |
2353 | <variablelist> | |
c464fd7e SG |
2354 | <varlistentry> |
2355 | <term> | |
2356 | <option>lxc.hook.autodev</option> | |
2357 | </term> | |
2358 | <listitem> | |
2359 | <para> | |
2360 | A hook to be run in the container's namespace after | |
2361 | mounting has been done and after any mount hooks have | |
2362 | run, but before the pivot_root, if | |
2363 | <option>lxc.autodev</option> == 1. | |
2364 | The purpose of this hook is to assist in populating the | |
2365 | /dev directory of the container when using the autodev | |
2366 | option for systemd based containers. The container's /dev | |
2367 | directory is relative to the | |
2368 | ${<option>LXC_ROOTFS_MOUNT</option>} environment | |
2369 | variable available when the hook is run. | |
2370 | </para> | |
2371 | </listitem> | |
2372 | </varlistentry> | |
55fc19a1 | 2373 | </variablelist> |
08dd2805 SH |
2374 | <variablelist> |
2375 | <varlistentry> | |
2376 | <term> | |
2377 | <option>lxc.hook.start-host</option> | |
2378 | </term> | |
2379 | <listitem> | |
2380 | <para> | |
2381 | A hook to be run in the host's namespace after the | |
2382 | container has been setup, and immediately before starting | |
2383 | the container init. | |
2384 | </para> | |
2385 | </listitem> | |
2386 | </varlistentry> | |
2387 | </variablelist> | |
55fc19a1 | 2388 | <variablelist> |
c464fd7e SG |
2389 | <varlistentry> |
2390 | <term> | |
2391 | <option>lxc.hook.start</option> | |
2392 | </term> | |
2393 | <listitem> | |
2394 | <para> | |
2395 | A hook to be run in the container's namespace immediately | |
2396 | before executing the container's init. This requires the | |
2397 | program to be available in the container. | |
2398 | </para> | |
2399 | </listitem> | |
2400 | </varlistentry> | |
55fc19a1 | 2401 | </variablelist> |
0a2b5ab1 WB |
2402 | <variablelist> |
2403 | <varlistentry> | |
2404 | <term> | |
2405 | <option>lxc.hook.stop</option> | |
2406 | </term> | |
2407 | <listitem> | |
2408 | <para> | |
2409 | A hook to be run in the host's namespace with references | |
2410 | to the container's namespaces after the container has been shut | |
2411 | down. For each namespace an extra argument is passed to the hook | |
2412 | containing the namespace's type and a filename that can be used to | |
2413 | obtain a file descriptor to the corresponding namespace, separated | |
2414 | by a colon. The type is the name as it would appear in the | |
2415 | <filename>/proc/PID/ns</filename> directory. | |
2416 | For instance for the mount namespace the argument usually looks | |
2417 | like <filename>mnt:/proc/PID/fd/12</filename>. | |
2418 | </para> | |
2419 | </listitem> | |
2420 | </varlistentry> | |
2421 | </variablelist> | |
55fc19a1 | 2422 | <variablelist> |
c464fd7e SG |
2423 | <varlistentry> |
2424 | <term> | |
2425 | <option>lxc.hook.post-stop</option> | |
2426 | </term> | |
2427 | <listitem> | |
2428 | <para> | |
2429 | A hook to be run in the host's namespace after the | |
2430 | container has been shut down. | |
2431 | </para> | |
2432 | </listitem> | |
2433 | </varlistentry> | |
55fc19a1 SG |
2434 | </variablelist> |
2435 | <variablelist> | |
c464fd7e SG |
2436 | <varlistentry> |
2437 | <term> | |
2438 | <option>lxc.hook.clone</option> | |
2439 | </term> | |
2440 | <listitem> | |
2441 | <para> | |
2442 | A hook to be run when the container is cloned to a new one. | |
2443 | See <citerefentry><refentrytitle><command>lxc-clone</command></refentrytitle> | |
2444 | <manvolnum>1</manvolnum></citerefentry> for more information. | |
2445 | </para> | |
2446 | </listitem> | |
2447 | </varlistentry> | |
55fc19a1 | 2448 | </variablelist> |
37cf711b SY |
2449 | <variablelist> |
2450 | <varlistentry> | |
2451 | <term> | |
2452 | <option>lxc.hook.destroy</option> | |
2453 | </term> | |
2454 | <listitem> | |
2455 | <para> | |
2456 | A hook to be run when the container is destroyed. | |
2457 | </para> | |
2458 | </listitem> | |
2459 | </varlistentry> | |
2460 | </variablelist> | |
55fc19a1 SG |
2461 | </refsect2> |
2462 | ||
2463 | <refsect2> | |
2464 | <title>Container hooks Environment Variables</title> | |
2465 | <para> | |
2466 | A number of environment variables are made available to the startup | |
2467 | hooks to provide configuration information and assist in the | |
2468 | functioning of the hooks. Not all variables are valid in all | |
2469 | contexts. In particular, all paths are relative to the host system | |
2470 | and, as such, not valid during the <option>lxc.hook.start</option> hook. | |
2471 | </para> | |
2472 | <variablelist> | |
c464fd7e SG |
2473 | <varlistentry> |
2474 | <term> | |
2475 | <option>LXC_NAME</option> | |
2476 | </term> | |
2477 | <listitem> | |
2478 | <para> | |
2479 | The LXC name of the container. Useful for logging messages | |
2480 | in common log environments. [<option>-n</option>] | |
2481 | </para> | |
2482 | </listitem> | |
2483 | </varlistentry> | |
55fc19a1 SG |
2484 | </variablelist> |
2485 | <variablelist> | |
c464fd7e SG |
2486 | <varlistentry> |
2487 | <term> | |
2488 | <option>LXC_CONFIG_FILE</option> | |
2489 | </term> | |
2490 | <listitem> | |
2491 | <para> | |
2492 | Host relative path to the container configuration file. This | |
2493 | gives the container to reference the original, top level, | |
2494 | configuration file for the container in order to locate any | |
2495 | additional configuration information not otherwise made | |
2496 | available. [<option>-f</option>] | |
2497 | </para> | |
2498 | </listitem> | |
2499 | </varlistentry> | |
55fc19a1 SG |
2500 | </variablelist> |
2501 | <variablelist> | |
c464fd7e SG |
2502 | <varlistentry> |
2503 | <term> | |
2504 | <option>LXC_CONSOLE</option> | |
2505 | </term> | |
2506 | <listitem> | |
2507 | <para> | |
2508 | The path to the console output of the container if not NULL. | |
3aed4934 | 2509 | [<option>-c</option>] [<option>lxc.console.path</option>] |
c464fd7e SG |
2510 | </para> |
2511 | </listitem> | |
2512 | </varlistentry> | |
55fc19a1 SG |
2513 | </variablelist> |
2514 | <variablelist> | |
c464fd7e SG |
2515 | <varlistentry> |
2516 | <term> | |
2517 | <option>LXC_CONSOLE_LOGPATH</option> | |
2518 | </term> | |
2519 | <listitem> | |
2520 | <para> | |
2521 | The path to the console log output of the container if not NULL. | |
2522 | [<option>-L</option>] | |
2523 | </para> | |
2524 | </listitem> | |
2525 | </varlistentry> | |
55fc19a1 SG |
2526 | </variablelist> |
2527 | <variablelist> | |
c464fd7e SG |
2528 | <varlistentry> |
2529 | <term> | |
2530 | <option>LXC_ROOTFS_MOUNT</option> | |
2531 | </term> | |
2532 | <listitem> | |
2533 | <para> | |
2534 | The mount location to which the container is initially bound. | |
2535 | This will be the host relative path to the container rootfs | |
2536 | for the container instance being started and is where changes | |
2537 | should be made for that instance. | |
2538 | [<option>lxc.rootfs.mount</option>] | |
2539 | </para> | |
2540 | </listitem> | |
2541 | </varlistentry> | |
55fc19a1 SG |
2542 | </variablelist> |
2543 | <variablelist> | |
c464fd7e SG |
2544 | <varlistentry> |
2545 | <term> | |
2546 | <option>LXC_ROOTFS_PATH</option> | |
2547 | </term> | |
2548 | <listitem> | |
2549 | <para> | |
2550 | The host relative path to the container root which has been | |
2551 | mounted to the rootfs.mount location. | |
7a96a068 | 2552 | [<option>lxc.rootfs.path</option>] |
c464fd7e SG |
2553 | </para> |
2554 | </listitem> | |
2555 | </varlistentry> | |
55fc19a1 | 2556 | </variablelist> |
07945418 KY |
2557 | <variablelist> |
2558 | <varlistentry> | |
2559 | <term> | |
2560 | <option>LXC_SRC_NAME</option> | |
2561 | </term> | |
2562 | <listitem> | |
2563 | <para> | |
2564 | Only for the clone hook. Is set to the original container name. | |
2565 | </para> | |
2566 | </listitem> | |
2567 | </varlistentry> | |
2568 | </variablelist> | |
c154af98 SG |
2569 | <variablelist> |
2570 | <varlistentry> | |
2571 | <term> | |
2572 | <option>LXC_TARGET</option> | |
2573 | </term> | |
2574 | <listitem> | |
2575 | <para> | |
2576 | Only for the stop hook. Is set to "stop" for a container | |
2577 | shutdown or "reboot" for a container reboot. | |
2578 | </para> | |
2579 | </listitem> | |
2580 | </varlistentry> | |
c4cafa08 SH |
2581 | </variablelist> |
2582 | <variablelist> | |
2583 | <varlistentry> | |
2584 | <term> | |
2585 | <option>LXC_CGNS_AWARE</option> | |
2586 | </term> | |
2587 | <listitem> | |
2588 | <para> | |
2589 | If unset, then this version of lxc is not aware of cgroup | |
2590 | namespaces. If set, it will be set to 1, and lxc is aware | |
2591 | of cgroup namespaces. Note this does not guarantee that | |
2592 | cgroup namespaces are enabled in the kernel. This is used | |
2593 | by the lxcfs mount hook. | |
2594 | </para> | |
2595 | </listitem> | |
2596 | </varlistentry> | |
c154af98 | 2597 | </variablelist> |
55fc19a1 SG |
2598 | </refsect2> |
2599 | <refsect2> | |
2600 | <title>Logging</title> | |
2601 | <para> | |
2602 | Logging can be configured on a per-container basis. By default, | |
2603 | depending upon how the lxc package was compiled, container startup | |
2604 | is logged only at the ERROR level, and logged to a file named after | |
2605 | the container (with '.log' appended) either under the container path, | |
2606 | or under @LOGPATH@. | |
2607 | </para> | |
2608 | <para> | |
2609 | Both the default log level and the log file can be specified in the | |
2610 | container configuration file, overriding the default behavior. Note | |
2611 | that the configuration file entries can in turn be overridden by the | |
2612 | command line options to <command>lxc-start</command>. | |
2613 | </para> | |
2614 | <variablelist> | |
c464fd7e SG |
2615 | <varlistentry> |
2616 | <term> | |
46cc906d | 2617 | <option>lxc.log.level</option> |
c464fd7e SG |
2618 | </term> |
2619 | <listitem> | |
2620 | <para> | |
2621 | The level at which to log. The log level is an integer in | |
2622 | the range of 0..8 inclusive, where a lower number means more | |
2623 | verbose debugging. In particular 0 = trace, 1 = debug, 2 = | |
2624 | info, 3 = notice, 4 = warn, 5 = error, 6 = critical, 7 = | |
2625 | alert, and 8 = fatal. If unspecified, the level defaults | |
2626 | to 5 (error), so that only errors and above are logged. | |
2627 | </para> | |
2628 | <para> | |
2629 | Note that when a script (such as either a hook script or a | |
2630 | network interface up or down script) is called, the script's | |
2631 | standard output is logged at level 1, debug. | |
2632 | </para> | |
2633 | </listitem> | |
2634 | </varlistentry> | |
2635 | <varlistentry> | |
2636 | <term> | |
5757588f | 2637 | <option>lxc.log.file</option> |
c464fd7e SG |
2638 | </term> |
2639 | <listitem> | |
2640 | <para> | |
2641 | The file to which logging info should be written. | |
2642 | </para> | |
2643 | </listitem> | |
2644 | </varlistentry> | |
204dfdf2 BD |
2645 | <varlistentry> |
2646 | <term> | |
46cc906d | 2647 | <option>lxc.log.syslog</option> |
204dfdf2 BD |
2648 | </term> |
2649 | <listitem> | |
2650 | <para> | |
2651 | Send logging info to syslog. It respects the log level defined in | |
46cc906d | 2652 | <command>lxc.log.level</command>. The argument should be the syslog |
204dfdf2 | 2653 | facility to use, valid ones are: daemon, local0, local1, local2, |
917420dd | 2654 | local3, local4, local5, local5, local6, local7. |
204dfdf2 BD |
2655 | </para> |
2656 | </listitem> | |
2657 | </varlistentry> | |
55fc19a1 SG |
2658 | </variablelist> |
2659 | </refsect2> | |
2660 | ||
2661 | <refsect2> | |
2662 | <title>Autostart</title> | |
2663 | <para> | |
2664 | The autostart options support marking which containers should be | |
2665 | auto-started and in what order. These options may be used by LXC tools | |
2666 | directly or by external tooling provided by the distributions. | |
2667 | </para> | |
2668 | ||
2669 | <variablelist> | |
2670 | <varlistentry> | |
2671 | <term> | |
2672 | <option>lxc.start.auto</option> | |
2673 | </term> | |
2674 | <listitem> | |
2675 | <para> | |
2676 | Whether the container should be auto-started. | |
2677 | Valid values are 0 (off) and 1 (on). | |
2678 | </para> | |
2679 | </listitem> | |
2680 | </varlistentry> | |
2681 | <varlistentry> | |
2682 | <term> | |
2683 | <option>lxc.start.delay</option> | |
2684 | </term> | |
2685 | <listitem> | |
2686 | <para> | |
2687 | How long to wait (in seconds) after the container is | |
2688 | started before starting the next one. | |
2689 | </para> | |
2690 | </listitem> | |
2691 | </varlistentry> | |
2692 | <varlistentry> | |
2693 | <term> | |
2694 | <option>lxc.start.order</option> | |
2695 | </term> | |
2696 | <listitem> | |
2697 | <para> | |
2698 | An integer used to sort the containers when auto-starting | |
0684250f LJ |
2699 | a series of containers at once. A lower value means an |
2700 | earlier start. | |
55fc19a1 SG |
2701 | </para> |
2702 | </listitem> | |
2703 | </varlistentry> | |
a8dfe4e0 WB |
2704 | <varlistentry> |
2705 | <term> | |
2706 | <option>lxc.monitor.unshare</option> | |
2707 | </term> | |
2708 | <listitem> | |
2709 | <para> | |
2710 | If not zero the mount namespace will be unshared from the host | |
2711 | before initializing the container (before running any pre-start | |
6039eaa2 WB |
2712 | hooks). This requires the CAP_SYS_ADMIN capability at startup. |
2713 | Default is 0. | |
a8dfe4e0 WB |
2714 | </para> |
2715 | </listitem> | |
2716 | </varlistentry> | |
258f8051 CB |
2717 | <varlistentry> |
2718 | <term> | |
2719 | <option>lxc.monitor.signal.pdeath</option> | |
2720 | </term> | |
2721 | <listitem> | |
2722 | <para> | |
2723 | Set the signal to be sent to the container's init when the lxc | |
2724 | monitor exits. By default it is set to SIGKILL which will cause | |
2725 | all container processes to be killed when the lxc monitor process | |
2726 | dies. | |
2727 | To ensure that containers stay alive even if lxc monitor dies set | |
2728 | this to 0. | |
2729 | </para> | |
2730 | </listitem> | |
2731 | </varlistentry> | |
55fc19a1 SG |
2732 | <varlistentry> |
2733 | <term> | |
2734 | <option>lxc.group</option> | |
2735 | </term> | |
2736 | <listitem> | |
2737 | <para> | |
2738 | A multi-value key (can be used multiple times) to put the | |
2739 | container in a container group. Those groups can then be | |
2740 | used (amongst other things) to start a series of related | |
2741 | containers. | |
2742 | </para> | |
2743 | </listitem> | |
2744 | </varlistentry> | |
2745 | </variablelist> | |
2746 | </refsect2> | |
015f0dd7 MW |
2747 | |
2748 | <refsect2> | |
2749 | <title>Autostart and System Boot</title> | |
2750 | <para> | |
2751 | Each container can be part of any number of groups or no group at all. | |
2752 | Two groups are special. One is the NULL group, i.e. the container does | |
2753 | not belong to any group. The other group is the "onboot" group. | |
2754 | </para> | |
2755 | ||
2756 | <para> | |
2757 | When the system boots with the LXC service enabled, it will first | |
2758 | attempt to boot any containers with lxc.start.auto == 1 that is a member | |
2759 | of the "onboot" group. The startup will be in order of lxc.start.order. | |
2760 | If an lxc.start.delay has been specified, that delay will be honored | |
2761 | before attempting to start the next container to give the current | |
2762 | container time to begin initialization and reduce overloading the host | |
2763 | system. After starting the members of the "onboot" group, the LXC system | |
2764 | will proceed to boot containers with lxc.start.auto == 1 which are not | |
2765 | members of any group (the NULL group) and proceed as with the onboot | |
2766 | group. | |
2767 | </para> | |
2768 | ||
2769 | </refsect2> | |
7c661726 MP |
2770 | |
2771 | <refsect2> | |
2772 | <title>Container Environment</title> | |
2773 | <para> | |
c464fd7e SG |
2774 | If you want to pass environment variables into the container (that |
2775 | is, environment variables which will be available to init and all of | |
2776 | its descendents), you can use <command>lxc.environment</command> | |
2777 | parameters to do so. Be careful that you do not pass in anything | |
2778 | sensitive; any process in the container which doesn't have its | |
2779 | environment scrubbed will have these variables available to it, and | |
2780 | environment variables are always available via | |
2781 | <command>/proc/PID/environ</command>. | |
7c661726 MP |
2782 | </para> |
2783 | ||
2784 | <para> | |
2785 | This configuration parameter can be specified multiple times; once | |
2786 | for each environment variable you wish to configure. | |
2787 | </para> | |
2788 | ||
2789 | <variablelist> | |
c464fd7e SG |
2790 | <varlistentry> |
2791 | <term> | |
2792 | <option>lxc.environment</option> | |
2793 | </term> | |
2794 | <listitem> | |
2795 | <para> | |
2796 | Specify an environment variable to pass into the container. | |
2797 | Example: | |
2798 | </para> | |
2799 | <programlisting> | |
2800 | lxc.environment = APP_ENV=production | |
2801 | lxc.environment = SYSLOG_SERVER=192.0.2.42 | |
2802 | </programlisting> | |
5eab47bc CB |
2803 | <para> |
2804 | It is possible to inherit host environment variables by setting the | |
2805 | name of the variable without a "=" sign. For example: | |
2806 | </para> | |
2807 | <programlisting> | |
2808 | lxc.environment = PATH | |
2809 | </programlisting> | |
c464fd7e SG |
2810 | </listitem> |
2811 | </varlistentry> | |
7c661726 MP |
2812 | </variablelist> |
2813 | </refsect2> | |
2814 | ||
55fc19a1 SG |
2815 | </refsect1> |
2816 | ||
2817 | <refsect1> | |
2818 | <title>Examples</title> | |
2819 | <para> | |
c464fd7e SG |
2820 | In addition to the few examples given below, you will find |
2821 | some other examples of configuration file in @DOCDIR@/examples | |
55fc19a1 SG |
2822 | </para> |
2823 | <refsect2> | |
2824 | <title>Network</title> | |
2825 | <para>This configuration sets up a container to use a veth pair | |
c464fd7e SG |
2826 | device with one side plugged to a bridge br0 (which has been |
2827 | configured before on the system by the administrator). The | |
2828 | virtual network device visible in the container is renamed to | |
2829 | eth0.</para> | |
55fc19a1 | 2830 | <programlisting> |
b67771bc | 2831 | lxc.uts.name = myhostname |
7fa3f2e9 | 2832 | lxc.net.0.type = veth |
2833 | lxc.net.0.flags = up | |
2834 | lxc.net.0.link = br0 | |
2835 | lxc.net.0.name = eth0 | |
2836 | lxc.net.0.hwaddr = 4a:49:43:49:79:bf | |
9ff60df2 | 2837 | lxc.net.0.ipv4.address = 10.2.3.5/24 10.2.3.255 |
2e44ae28 | 2838 | lxc.net.0.ipv6.address = 2003:db8:1:0:214:1234:fe0b:3597 |
55fc19a1 SG |
2839 | </programlisting> |
2840 | </refsect2> | |
2841 | ||
2842 | <refsect2> | |
2843 | <title>UID/GID mapping</title> | |
2844 | <para>This configuration will map both user and group ids in the | |
2845 | range 0-9999 in the container to the ids 100000-109999 on the host. | |
2846 | </para> | |
2847 | <programlisting> | |
bdcbb6b3 CB |
2848 | lxc.idmap = u 0 100000 10000 |
2849 | lxc.idmap = g 0 100000 10000 | |
55fc19a1 SG |
2850 | </programlisting> |
2851 | </refsect2> | |
2852 | ||
2853 | <refsect2> | |
2854 | <title>Control group</title> | |
2855 | <para>This configuration will setup several control groups for | |
2856 | the application, cpuset.cpus restricts usage of the defined cpu, | |
2857 | cpus.share prioritize the control group, devices.allow makes | |
2858 | usable the specified devices.</para> | |
2859 | <programlisting> | |
c464fd7e SG |
2860 | lxc.cgroup.cpuset.cpus = 0,1 |
2861 | lxc.cgroup.cpu.shares = 1234 | |
2862 | lxc.cgroup.devices.deny = a | |
2863 | lxc.cgroup.devices.allow = c 1:3 rw | |
2864 | lxc.cgroup.devices.allow = b 8:0 rw | |
55fc19a1 SG |
2865 | </programlisting> |
2866 | </refsect2> | |
2867 | ||
2868 | <refsect2> | |
2869 | <title>Complex configuration</title> | |
2870 | <para>This example show a complex configuration making a complex | |
2871 | network stack, using the control groups, setting a new hostname, | |
2872 | mounting some locations and a changing root file system.</para> | |
2873 | <programlisting> | |
b67771bc | 2874 | lxc.uts.name = complex |
7fa3f2e9 | 2875 | lxc.net.0.type = veth |
2876 | lxc.net.0.flags = up | |
2877 | lxc.net.0.link = br0 | |
2878 | lxc.net.0.hwaddr = 4a:49:43:49:79:bf | |
9ff60df2 | 2879 | lxc.net.0.ipv4.address = 10.2.3.5/24 10.2.3.255 |
2e44ae28 CB |
2880 | lxc.net.0.ipv6.address = 2003:db8:1:0:214:1234:fe0b:3597 |
2881 | lxc.net.0.ipv6.address = 2003:db8:1:0:214:5432:feab:3588 | |
7fa3f2e9 | 2882 | lxc.net.1.type = macvlan |
2883 | lxc.net.1.flags = up | |
2884 | lxc.net.1.link = eth0 | |
2885 | lxc.net.1.hwaddr = 4a:49:43:49:79:bd | |
9ff60df2 CB |
2886 | lxc.net.1.ipv4.address = 10.2.3.4/24 |
2887 | lxc.net.1.ipv4.address = 192.168.10.125/24 | |
2e44ae28 | 2888 | lxc.net.1.ipv6.address = 2003:db8:1:0:214:1234:fe0b:3596 |
7fa3f2e9 | 2889 | lxc.net.2.type = phys |
2890 | lxc.net.2.flags = up | |
2891 | lxc.net.2.link = dummy0 | |
2892 | lxc.net.2.hwaddr = 4a:49:43:49:79:ff | |
9ff60df2 | 2893 | lxc.net.2.ipv4.address = 10.2.3.6/24 |
2e44ae28 | 2894 | lxc.net.2.ipv6.address = 2003:db8:1:0:214:1234:fe0b:3297 |
c464fd7e SG |
2895 | lxc.cgroup.cpuset.cpus = 0,1 |
2896 | lxc.cgroup.cpu.shares = 1234 | |
2897 | lxc.cgroup.devices.deny = a | |
2898 | lxc.cgroup.devices.allow = c 1:3 rw | |
2899 | lxc.cgroup.devices.allow = b 8:0 rw | |
47148e96 | 2900 | lxc.mount.fstab = /etc/fstab.complex |
c464fd7e | 2901 | lxc.mount.entry = /lib /root/myrootfs/lib none ro,bind 0 0 |
7a96a068 | 2902 | lxc.rootfs.path = dir:/mnt/rootfs.complex |
c464fd7e SG |
2903 | lxc.cap.drop = sys_module mknod setuid net_raw |
2904 | lxc.cap.drop = mac_override | |
55fc19a1 SG |
2905 | </programlisting> |
2906 | </refsect2> | |
2907 | ||
2908 | </refsect1> | |
2909 | ||
2910 | <refsect1> | |
2911 | <title>See Also</title> | |
2912 | <simpara> | |
2913 | <citerefentry> | |
c464fd7e SG |
2914 | <refentrytitle><command>chroot</command></refentrytitle> |
2915 | <manvolnum>1</manvolnum> | |
55fc19a1 SG |
2916 | </citerefentry>, |
2917 | ||
2918 | <citerefentry> | |
c464fd7e SG |
2919 | <refentrytitle><command>pivot_root</command></refentrytitle> |
2920 | <manvolnum>8</manvolnum> | |
55fc19a1 SG |
2921 | </citerefentry>, |
2922 | ||
2923 | <citerefentry> | |
c464fd7e SG |
2924 | <refentrytitle><filename>fstab</filename></refentrytitle> |
2925 | <manvolnum>5</manvolnum> | |
55fc19a1 SG |
2926 | </citerefentry>, |
2927 | ||
2928 | <citerefentry> | |
c464fd7e SG |
2929 | <refentrytitle><filename>capabilities</filename></refentrytitle> |
2930 | <manvolnum>7</manvolnum> | |
55fc19a1 SG |
2931 | </citerefentry> |
2932 | </simpara> | |
2933 | </refsect1> | |
2934 | ||
2935 | &seealso; | |
2936 | ||
2937 | <refsect1> | |
2938 | <title>Author</title> | |
2939 | <para>Daniel Lezcano <email>daniel.lezcano@free.fr</email></para> | |
2940 | </refsect1> | |
2941 | ||
2942 | </refentry> | |
2943 | ||
2944 | <!-- Keep this comment at the end of the file | |
2945 | Local variables: | |
2946 | mode: sgml | |
2947 | sgml-omittag:t | |
2948 | sgml-shorttag:t | |
2949 | sgml-minimize-attributes:nil | |
2950 | sgml-always-quote-attributes:t | |
2951 | sgml-indent-step:2 | |
2952 | sgml-indent-data:t | |
2953 | sgml-parent-document:nil | |
2954 | sgml-default-dtd-file:nil | |
2955 | sgml-exposed-tags:nil | |
2956 | sgml-local-catalogs:nil | |
2957 | sgml-local-ecat-files:nil | |
2958 | End: | |
2959 | --> |