]>
Commit | Line | Data |
---|---|---|
55fc19a1 SG |
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> | |
72 | LXC has supports unprivileged containers. Unprivileged containers are | |
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> | |
102 | LXC namespaces configuration keys by using 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. | |
258 | ||
259 | This option is ignored when using lxc-execute. | |
260 | ||
261 | Defaults to: /sbin/init | |
262 | </para> | |
5cda27c1 SH |
263 | <variablelist> |
264 | <varlistentry> | |
265 | <term> | |
266 | <option>lxc.execute.cmd</option> | |
267 | </term> | |
268 | <listitem> | |
269 | <para> | |
270 | Absolute path from container rootfs to the binary to run by default. This | |
271 | mostly makes sense for lxc-execute. | |
272 | </para> | |
273 | </listitem> | |
274 | </varlistentry> | |
275 | </variablelist> | |
67c660d0 | 276 | <variablelist> |
936762f3 BP |
277 | <varlistentry> |
278 | <term> | |
9dcf7b4d | 279 | <option>lxc.init.cmd</option> |
936762f3 BP |
280 | </term> |
281 | <listitem> | |
282 | <para> | |
283 | Absolute path from container rootfs to the binary to use as init. | |
284 | </para> | |
285 | </listitem> | |
286 | </varlistentry> | |
67c660d0 SG |
287 | </variablelist> |
288 | </refsect2> | |
289 | ||
dbca9237 PT |
290 | <refsect2> |
291 | <title>Init ID</title> | |
292 | <para> | |
b9986e43 CB |
293 | Sets the UID/GID to use for the init system, and subsequent commands. |
294 | Note that using a non-root uid when booting a system container will | |
295 | likely not work due to missing privileges. Setting the UID/GID is mostly | |
296 | useful when running application container. | |
dbca9237 PT |
297 | |
298 | Defaults to: UID(0), GID(0) | |
299 | </para> | |
300 | <variablelist> | |
301 | <varlistentry> | |
302 | <term> | |
9dcf7b4d | 303 | <option>lxc.init.uid</option> |
dbca9237 PT |
304 | </term> |
305 | <listitem> | |
306 | <para> | |
b9986e43 | 307 | UID to use for init. |
dbca9237 PT |
308 | </para> |
309 | </listitem> | |
310 | </varlistentry> | |
311 | <varlistentry> | |
312 | <term> | |
9dcf7b4d | 313 | <option>lxc.init.gid</option> |
dbca9237 PT |
314 | </term> |
315 | <listitem> | |
316 | <para> | |
b9986e43 | 317 | GID to use for init. |
dbca9237 PT |
318 | </para> |
319 | </listitem> | |
320 | </varlistentry> | |
321 | </variablelist> | |
322 | </refsect2> | |
323 | ||
4e6eb26b CB |
324 | <refsect2> |
325 | <title>Ephemeral</title> | |
326 | <para> | |
327 | Allows one to specify whether a container will be destroyed on shutdown. | |
328 | </para> | |
329 | <variablelist> | |
330 | <varlistentry> | |
331 | <term> | |
332 | <option>lxc.ephemeral</option> | |
333 | </term> | |
334 | <listitem> | |
335 | <para> | |
336 | The only allowed values are 0 and 1. Set this to 1 to destroy a | |
337 | container on shutdown. | |
338 | </para> | |
339 | </listitem> | |
340 | </varlistentry> | |
341 | </variablelist> | |
342 | </refsect2> | |
343 | ||
55fc19a1 SG |
344 | <refsect2> |
345 | <title>Network</title> | |
346 | <para> | |
c464fd7e SG |
347 | The network section defines how the network is virtualized in |
348 | the container. The network virtualization acts at layer | |
349 | two. In order to use the network virtualization, parameters | |
350 | must be specified to define the network interfaces of the | |
351 | container. Several virtual interfaces can be assigned and used | |
352 | in a container even if the system has only one physical | |
353 | network interface. | |
55fc19a1 SG |
354 | </para> |
355 | <variablelist> | |
020104c3 MH |
356 | <varlistentry> |
357 | <term> | |
7fa3f2e9 | 358 | <option>lxc.net</option> |
020104c3 MH |
359 | </term> |
360 | <listitem> | |
361 | <para> | |
362 | may be used without a value to clear all previous network options. | |
363 | </para> | |
364 | </listitem> | |
365 | </varlistentry> | |
c464fd7e SG |
366 | <varlistentry> |
367 | <term> | |
7fa3f2e9 | 368 | <option>lxc.net.[i].type</option> |
c464fd7e SG |
369 | </term> |
370 | <listitem> | |
371 | <para> | |
372 | specify what kind of network virtualization to be used | |
b9986e43 CB |
373 | for the container. |
374 | Multiple networks can be specified by using an additional index | |
375 | <option>i</option> | |
7fa3f2e9 | 376 | after all <option>lxc.net.*</option> keys. For example, |
377 | <option>lxc.net.0.type = veth</option> and | |
378 | <option>lxc.net.1.type = veth</option> specify two different | |
b9986e43 CB |
379 | networks of the same type. All keys sharing the same index |
380 | <option>i</option> will be treated as belonging to the same | |
7fa3f2e9 | 381 | network. For example, <option>lxc.net.0.link = br0</option> |
382 | will belong to <option>lxc.net.0.type</option>. | |
b9986e43 | 383 | Currently, the different virtualization types can be: |
c464fd7e SG |
384 | </para> |
385 | ||
386 | <para> | |
387 | <option>none:</option> will cause the container to share | |
388 | the host's network namespace. This means the host | |
389 | network devices are usable in the container. It also | |
390 | means that if both the container and host have upstart as | |
391 | init, 'halt' in a container (for instance) will shut down the | |
392 | host. | |
393 | </para> | |
394 | ||
395 | <para> | |
396 | <option>empty:</option> will create only the loopback | |
397 | interface. | |
398 | </para> | |
399 | ||
400 | <para> | |
38005c54 MA |
401 | <option>veth:</option> a virtual ethernet pair |
402 | device is created with one side assigned to the container | |
403 | and the other side attached to a bridge specified by | |
7fa3f2e9 | 404 | the <option>lxc.net.[i].link</option> option. |
38005c54 MA |
405 | If the bridge is not specified, then the veth pair device |
406 | will be created but not attached to any bridge. | |
407 | Otherwise, the bridge has to be created on the system | |
408 | before starting the container. | |
409 | <command>lxc</command> won't handle any | |
410 | configuration outside of the container. | |
411 | By default, <command>lxc</command> chooses a name for the | |
c464fd7e | 412 | network device belonging to the outside of the |
38005c54 MA |
413 | container, but if you wish to handle |
414 | this name yourselves, you can tell <command>lxc</command> | |
c464fd7e | 415 | to set a specific name with |
7fa3f2e9 | 416 | the <option>lxc.net.[i].veth.pair</option> option (except for |
c464fd7e SG |
417 | unprivileged containers where this option is ignored for security |
418 | reasons). | |
419 | </para> | |
420 | ||
421 | <para> | |
422 | <option>vlan:</option> a vlan interface is linked with | |
423 | the interface specified by | |
7fa3f2e9 | 424 | the <option>lxc.net.[i].link</option> and assigned to |
c464fd7e | 425 | the container. The vlan identifier is specified with the |
7fa3f2e9 | 426 | option <option>lxc.net.[i].vlan.id</option>. |
c464fd7e SG |
427 | </para> |
428 | ||
429 | <para> | |
430 | <option>macvlan:</option> a macvlan interface is linked | |
431 | with the interface specified by | |
7fa3f2e9 | 432 | the <option>lxc.net.[i].link</option> and assigned to |
c464fd7e | 433 | the container. |
7fa3f2e9 | 434 | <option>lxc.net.[i].macvlan.mode</option> specifies the |
c464fd7e SG |
435 | mode the macvlan will use to communicate between |
436 | different macvlan on the same upper device. The accepted | |
c15ea607 EL |
437 | modes are <option>private</option>, <option>vepa</option>, |
438 | <option>bridge</option> and <option>passthru</option>. | |
439 | In <option>private</option> mode, the device never | |
440 | communicates with any other device on the same upper_dev (default). | |
441 | In <option>vepa</option> mode, the new Virtual Ethernet Port | |
c464fd7e SG |
442 | Aggregator (VEPA) mode, it assumes that the adjacent |
443 | bridge returns all frames where both source and | |
444 | destination are local to the macvlan port, i.e. the | |
445 | bridge is set up as a reflective relay. Broadcast | |
446 | frames coming in from the upper_dev get flooded to all | |
447 | macvlan interfaces in VEPA mode, local frames are not | |
c15ea607 | 448 | delivered locally. In <option>bridge</option> mode, it |
c464fd7e SG |
449 | provides the behavior of a simple bridge between |
450 | different macvlan interfaces on the same port. Frames | |
451 | from one interface to another one get delivered directly | |
452 | and are not sent out externally. Broadcast frames get | |
453 | flooded to all other bridge ports and to the external | |
454 | interface, but when they come back from a reflective | |
455 | relay, we don't deliver them again. Since we know all | |
456 | the MAC addresses, the macvlan bridge mode does not | |
c15ea607 EL |
457 | require learning or STP like the bridge module does. In |
458 | <option>passthru</option> mode, all frames received by | |
459 | the physical interface are forwarded to the macvlan | |
460 | interface. Only one macvlan interface in <option>passthru</option> | |
461 | mode is possible for one physical interface. | |
c464fd7e SG |
462 | </para> |
463 | ||
464 | <para> | |
465 | <option>phys:</option> an already existing interface | |
7fa3f2e9 | 466 | specified by the <option>lxc.net.[i].link</option> is |
c464fd7e SG |
467 | assigned to the container. |
468 | </para> | |
469 | </listitem> | |
470 | </varlistentry> | |
471 | ||
472 | <varlistentry> | |
473 | <term> | |
7fa3f2e9 | 474 | <option>lxc.net.[i].flags</option> |
c464fd7e SG |
475 | </term> |
476 | <listitem> | |
477 | <para> | |
b9986e43 | 478 | Specify an action to do for the network. |
c464fd7e SG |
479 | </para> |
480 | ||
481 | <para><option>up:</option> activates the interface. | |
482 | </para> | |
483 | </listitem> | |
484 | </varlistentry> | |
485 | ||
486 | <varlistentry> | |
487 | <term> | |
7fa3f2e9 | 488 | <option>lxc.net.[i].link</option> |
c464fd7e SG |
489 | </term> |
490 | <listitem> | |
491 | <para> | |
b9986e43 CB |
492 | Specify the interface to be used for real network traffic. |
493 | </para> | |
c464fd7e SG |
494 | </listitem> |
495 | </varlistentry> | |
496 | ||
497 | <varlistentry> | |
498 | <term> | |
7fa3f2e9 | 499 | <option>lxc.net.[i].mtu</option> |
c464fd7e SG |
500 | </term> |
501 | <listitem> | |
502 | <para> | |
b9986e43 | 503 | Specify the maximum transfer unit for this interface. |
c464fd7e SG |
504 | </para> |
505 | </listitem> | |
506 | </varlistentry> | |
507 | ||
508 | <varlistentry> | |
509 | <term> | |
7fa3f2e9 | 510 | <option>lxc.net.[i].name</option> |
c464fd7e SG |
511 | </term> |
512 | <listitem> | |
513 | <para> | |
b9986e43 CB |
514 | The interface name is dynamically allocated, but if another name |
515 | is needed because the configuration files being used by the | |
516 | container use a generic name, eg. eth0, this option will rename | |
517 | the interface in the container. | |
c464fd7e SG |
518 | </para> |
519 | </listitem> | |
520 | </varlistentry> | |
521 | ||
522 | <varlistentry> | |
523 | <term> | |
7fa3f2e9 | 524 | <option>lxc.net.[i].hwaddr</option> |
c464fd7e SG |
525 | </term> |
526 | <listitem> | |
527 | <para> | |
b9986e43 CB |
528 | The interface mac address is dynamically allocated by default to |
529 | the virtual interface, but in some cases, this is needed to | |
530 | resolve a mac address conflict or to always have the same | |
531 | link-local ipv6 address. Any "x" in address will be replaced by | |
532 | random value, this allows setting hwaddr templates. | |
c464fd7e SG |
533 | </para> |
534 | </listitem> | |
535 | </varlistentry> | |
536 | ||
537 | <varlistentry> | |
538 | <term> | |
9ff60df2 | 539 | <option>lxc.net.[i].ipv4.address</option> |
c464fd7e SG |
540 | </term> |
541 | <listitem> | |
542 | <para> | |
b9986e43 CB |
543 | Specify the ipv4 address to assign to the virtualized interface. |
544 | Several lines specify several ipv4 addresses. The address is in | |
545 | format x.y.z.t/m, eg. 192.168.1.123/24. | |
c464fd7e SG |
546 | </para> |
547 | </listitem> | |
548 | </varlistentry> | |
549 | ||
550 | <varlistentry> | |
551 | <term> | |
7fa3f2e9 | 552 | <option>lxc.net.[i].ipv4.gateway</option> |
c464fd7e SG |
553 | </term> |
554 | <listitem> | |
555 | <para> | |
b9986e43 CB |
556 | Specify the ipv4 address to use as the gateway inside the |
557 | container. The address is in format x.y.z.t, eg. 192.168.1.123. | |
c464fd7e SG |
558 | |
559 | Can also have the special value <option>auto</option>, | |
560 | which means to take the primary address from the bridge | |
561 | interface (as specified by the | |
7fa3f2e9 | 562 | <option>lxc.net.[i].link</option> option) and use that as |
c464fd7e SG |
563 | the gateway. <option>auto</option> is only available when |
564 | using the <option>veth</option> and | |
565 | <option>macvlan</option> network types. | |
566 | </para> | |
567 | </listitem> | |
568 | </varlistentry> | |
569 | ||
570 | ||
571 | <varlistentry> | |
572 | <term> | |
2e44ae28 | 573 | <option>lxc.net.[i].ipv6.address</option> |
c464fd7e SG |
574 | </term> |
575 | <listitem> | |
576 | <para> | |
b9986e43 CB |
577 | Specify the ipv6 address to assign to the virtualized |
578 | interface. Several lines specify several ipv6 addresses. The | |
579 | address is in format x::y/m, eg. | |
580 | 2003:db8:1:0:214:1234:fe0b:3596/64 | |
c464fd7e SG |
581 | </para> |
582 | </listitem> | |
583 | </varlistentry> | |
584 | ||
585 | <varlistentry> | |
586 | <term> | |
7fa3f2e9 | 587 | <option>lxc.net.[i].ipv6.gateway</option> |
c464fd7e SG |
588 | </term> |
589 | <listitem> | |
590 | <para> | |
b9986e43 CB |
591 | Specify the ipv6 address to use as the gateway inside the |
592 | container. The address is in format x::y, eg. 2003:db8:1:0::1 | |
c464fd7e SG |
593 | |
594 | Can also have the special value <option>auto</option>, | |
595 | which means to take the primary address from the bridge | |
596 | interface (as specified by the | |
7fa3f2e9 | 597 | <option>lxc.net.[i].link</option> option) and use that as |
c464fd7e SG |
598 | the gateway. <option>auto</option> is only available when |
599 | using the <option>veth</option> and | |
600 | <option>macvlan</option> network types. | |
601 | </para> | |
602 | </listitem> | |
603 | </varlistentry> | |
604 | ||
605 | <varlistentry> | |
606 | <term> | |
7fa3f2e9 | 607 | <option>lxc.net.[i].script.up</option> |
c464fd7e SG |
608 | </term> |
609 | <listitem> | |
610 | <para> | |
b9986e43 | 611 | Add a configuration option to specify a script to be |
c464fd7e SG |
612 | executed after creating and configuring the network used |
613 | from the host side. The following arguments are passed | |
614 | to the script: container name and config section name | |
615 | (net) Additional arguments depend on the config section | |
616 | employing a script hook; the following are used by the | |
617 | network system: execution context (up), network type | |
618 | (empty/veth/macvlan/phys), Depending on the network | |
619 | type, other arguments may be passed: | |
620 | veth/macvlan/phys. And finally (host-sided) device name. | |
621 | </para> | |
622 | <para> | |
623 | Standard output from the script is logged at debug level. | |
624 | Standard error is not logged, but can be captured by the | |
625 | hook redirecting its standard error to standard output. | |
626 | </para> | |
627 | </listitem> | |
628 | </varlistentry> | |
629 | ||
630 | <varlistentry> | |
631 | <term> | |
7fa3f2e9 | 632 | <option>lxc.net.[i].script.down</option> |
c464fd7e SG |
633 | </term> |
634 | <listitem> | |
635 | <para> | |
b9986e43 | 636 | Add a configuration option to specify a script to be |
c464fd7e SG |
637 | executed before destroying the network used from the |
638 | host side. The following arguments are passed to the | |
639 | script: container name and config section name (net) | |
640 | Additional arguments depend on the config section | |
641 | employing a script hook; the following are used by the | |
642 | network system: execution context (down), network type | |
643 | (empty/veth/macvlan/phys), Depending on the network | |
644 | type, other arguments may be passed: | |
645 | veth/macvlan/phys. And finally (host-sided) device name. | |
646 | </para> | |
647 | <para> | |
648 | Standard output from the script is logged at debug level. | |
649 | Standard error is not logged, but can be captured by the | |
650 | hook redirecting its standard error to standard output. | |
651 | </para> | |
652 | </listitem> | |
653 | </varlistentry> | |
55fc19a1 SG |
654 | </variablelist> |
655 | </refsect2> | |
656 | ||
657 | <refsect2> | |
658 | <title>New pseudo tty instance (devpts)</title> | |
659 | <para> | |
c464fd7e SG |
660 | For stricter isolation the container can have its own private |
661 | instance of the pseudo tty. | |
55fc19a1 SG |
662 | </para> |
663 | <variablelist> | |
c464fd7e SG |
664 | <varlistentry> |
665 | <term> | |
232763d6 | 666 | <option>lxc.pty.max</option> |
c464fd7e SG |
667 | </term> |
668 | <listitem> | |
669 | <para> | |
670 | If set, the container will have a new pseudo tty | |
671 | instance, making this private to it. The value specifies | |
55fc19a1 SG |
672 | the maximum number of pseudo ttys allowed for a pts |
673 | instance (this limitation is not implemented yet). | |
c464fd7e SG |
674 | </para> |
675 | </listitem> | |
676 | </varlistentry> | |
55fc19a1 SG |
677 | </variablelist> |
678 | </refsect2> | |
679 | ||
680 | <refsect2> | |
681 | <title>Container system console</title> | |
682 | <para> | |
c464fd7e SG |
683 | If the container is configured with a root filesystem and the |
684 | inittab file is setup to use the console, you may want to specify | |
685 | where the output of this console goes. | |
55fc19a1 SG |
686 | </para> |
687 | <variablelist> | |
c464fd7e SG |
688 | <varlistentry> |
689 | <term> | |
690 | <option>lxc.console.logfile</option> | |
691 | </term> | |
692 | <listitem> | |
693 | <para> | |
694 | Specify a path to a file where the console output will | |
695 | be written. | |
696 | </para> | |
697 | </listitem> | |
698 | </varlistentry> | |
699 | <varlistentry> | |
700 | <term> | |
3aed4934 | 701 | <option>lxc.console.path</option> |
c464fd7e SG |
702 | </term> |
703 | <listitem> | |
704 | <para> | |
705 | Specify a path to a device to which the console will be | |
6e3bb289 CB |
706 | attached. The keyword 'none' will simply disable the |
707 | console. Note, when specifying 'none' and creating a device node | |
708 | for the console in the container at /dev/console or bind-mounting | |
709 | the hosts's /dev/console into the container at /dev/console the | |
710 | container will have direct access to the hosts's /dev/console. | |
711 | This is dangerous when the container has write access to the | |
712 | device and should thus be used with caution. | |
c464fd7e SG |
713 | </para> |
714 | </listitem> | |
715 | </varlistentry> | |
55fc19a1 SG |
716 | </variablelist> |
717 | </refsect2> | |
718 | ||
719 | <refsect2> | |
720 | <title>Console through the ttys</title> | |
721 | <para> | |
c464fd7e SG |
722 | This option is useful if the container is configured with a root |
723 | filesystem and the inittab file is setup to launch a getty on the | |
724 | ttys. The option specifies the number of ttys to be available for | |
725 | the container. The number of gettys in the inittab file of the | |
726 | container should not be greater than the number of ttys specified | |
727 | in this option, otherwise the excess getty sessions will die and | |
728 | respawn indefinitely giving annoying messages on the console or in | |
729 | <filename>/var/log/messages</filename>. | |
55fc19a1 SG |
730 | </para> |
731 | <variablelist> | |
c464fd7e SG |
732 | <varlistentry> |
733 | <term> | |
fe1c5887 | 734 | <option>lxc.tty.max</option> |
c464fd7e SG |
735 | </term> |
736 | <listitem> | |
737 | <para> | |
738 | Specify the number of tty to make available to the | |
739 | container. | |
740 | </para> | |
741 | </listitem> | |
742 | </varlistentry> | |
55fc19a1 SG |
743 | </variablelist> |
744 | </refsect2> | |
745 | ||
746 | <refsect2> | |
747 | <title>Console devices location</title> | |
748 | <para> | |
749 | LXC consoles are provided through Unix98 PTYs created on the | |
c464fd7e SG |
750 | host and bind-mounted over the expected devices in the container. |
751 | By default, they are bind-mounted over <filename>/dev/console</filename> | |
752 | and <filename>/dev/ttyN</filename>. This can prevent package upgrades | |
753 | in the guest. Therefore you can specify a directory location (under | |
754 | <filename>/dev</filename> under which LXC will create the files and | |
755 | bind-mount over them. These will then be symbolically linked to | |
756 | <filename>/dev/console</filename> and <filename>/dev/ttyN</filename>. | |
757 | A package upgrade can then succeed as it is able to remove and replace | |
758 | the symbolic links. | |
55fc19a1 SG |
759 | </para> |
760 | <variablelist> | |
c464fd7e SG |
761 | <varlistentry> |
762 | <term> | |
fe1c5887 | 763 | <option>lxc.tty.dir</option> |
c464fd7e SG |
764 | </term> |
765 | <listitem> | |
766 | <para> | |
767 | Specify a directory under <filename>/dev</filename> | |
6e3bb289 CB |
768 | under which to create the container console devices. Note that LXC |
769 | will move any bind-mounts or device nodes for /dev/console into | |
770 | this directory. | |
c464fd7e SG |
771 | </para> |
772 | </listitem> | |
773 | </varlistentry> | |
55fc19a1 SG |
774 | </variablelist> |
775 | </refsect2> | |
776 | ||
777 | <refsect2> | |
778 | <title>/dev directory</title> | |
779 | <para> | |
c464fd7e SG |
780 | By default, lxc creates a few symbolic links (fd,stdin,stdout,stderr) |
781 | in the container's <filename>/dev</filename> directory but does not | |
782 | automatically create device node entries. This allows the container's | |
783 | <filename>/dev</filename> to be set up as needed in the container | |
784 | rootfs. If lxc.autodev is set to 1, then after mounting the container's | |
785 | rootfs LXC will mount a fresh tmpfs under <filename>/dev</filename> | |
c35d2909 | 786 | (limited to 500k) and fill in a minimal set of initial devices. |
55fc19a1 SG |
787 | This is generally required when starting a container containing |
788 | a "systemd" based "init" but may be optional at other times. Additional | |
789 | devices in the containers /dev directory may be created through the | |
790 | use of the <option>lxc.hook.autodev</option> hook. | |
791 | </para> | |
792 | <variablelist> | |
c464fd7e SG |
793 | <varlistentry> |
794 | <term> | |
795 | <option>lxc.autodev</option> | |
796 | </term> | |
797 | <listitem> | |
798 | <para> | |
124fa0a8 | 799 | Set this to 0 to stop LXC from mounting and populating a minimal |
c464fd7e SG |
800 | <filename>/dev</filename> when starting the container. |
801 | </para> | |
802 | </listitem> | |
803 | </varlistentry> | |
55fc19a1 | 804 | </variablelist> |
55fc19a1 SG |
805 | </refsect2> |
806 | ||
807 | <refsect2> | |
808 | <title>Mount points</title> | |
809 | <para> | |
c464fd7e SG |
810 | The mount points section specifies the different places to be |
811 | mounted. These mount points will be private to the container | |
812 | and won't be visible by the processes running outside of the | |
813 | container. This is useful to mount /etc, /var or /home for | |
814 | examples. | |
55fc19a1 | 815 | </para> |
592fd47a SH |
816 | <para> |
817 | NOTE - LXC will generally ensure that mount targets and relative | |
818 | bind-mount sources are properly confined under the container | |
819 | root, to avoid attacks involving over-mounting host directories | |
820 | and files. (Symbolic links in absolute mount sources are ignored) | |
821 | However, if the container configuration first mounts a directory which | |
822 | is under the control of the container user, such as /home/joe, into | |
823 | the container at some <filename>path</filename>, and then mounts | |
824 | under <filename>path</filename>, then a TOCTTOU attack would be | |
825 | possible where the container user modifies a symbolic link under | |
826 | his home directory at just the right time. | |
827 | </para> | |
55fc19a1 | 828 | <variablelist> |
c464fd7e SG |
829 | <varlistentry> |
830 | <term> | |
47148e96 | 831 | <option>lxc.mount.fstab</option> |
c464fd7e SG |
832 | </term> |
833 | <listitem> | |
834 | <para> | |
835 | specify a file location in | |
836 | the <filename>fstab</filename> format, containing the | |
837 | mount information. The mount target location can and in | |
838 | most cases should be a relative path, which will become | |
839 | relative to the mounted container root. For instance, | |
840 | </para> | |
b9986e43 CB |
841 | <programlisting> |
842 | proc proc proc nodev,noexec,nosuid 0 0 | |
843 | </programlisting> | |
c464fd7e SG |
844 | <para> |
845 | Will mount a proc filesystem under the container's /proc, | |
846 | regardless of where the root filesystem comes from. This | |
847 | is resilient to block device backed filesystems as well as | |
848 | container cloning. | |
849 | </para> | |
850 | <para> | |
851 | Note that when mounting a filesystem from an | |
852 | image file or block device the third field (fs_vfstype) | |
853 | cannot be auto as with | |
55fc19a1 | 854 | <citerefentry> |
c464fd7e | 855 | <refentrytitle>mount</refentrytitle> |
55fc19a1 SG |
856 | <manvolnum>8</manvolnum> |
857 | </citerefentry> | |
858 | but must be explicitly specified. | |
c464fd7e SG |
859 | </para> |
860 | </listitem> | |
861 | </varlistentry> | |
862 | ||
863 | <varlistentry> | |
864 | <term> | |
865 | <option>lxc.mount.entry</option> | |
866 | </term> | |
867 | <listitem> | |
868 | <para> | |
869 | specify a mount point corresponding to a line in the | |
870 | fstab format. | |
f5b67b36 NC |
871 | |
872 | Moreover lxc add two options to mount. | |
873 | <option>optional</option> don't fail if mount does not work. | |
874 | <option>create=dir</option> or <option>create=file</option> | |
875 | to create dir (or file) when the point will be mounted. | |
c464fd7e SG |
876 | </para> |
877 | </listitem> | |
878 | </varlistentry> | |
879 | ||
880 | <varlistentry> | |
881 | <term> | |
882 | <option>lxc.mount.auto</option> | |
883 | </term> | |
884 | <listitem> | |
885 | <para> | |
886 | specify which standard kernel file systems should be | |
887 | automatically mounted. This may dramatically simplify | |
888 | the configuration. The file systems are: | |
889 | </para> | |
890 | <itemizedlist> | |
891 | <listitem> | |
892 | <para> | |
893 | <option>proc:mixed</option> (or <option>proc</option>): | |
894 | mount <filename>/proc</filename> as read-write, but | |
895 | remount <filename>/proc/sys</filename> and | |
896 | <filename>/proc/sysrq-trigger</filename> read-only | |
897 | for security / container isolation purposes. | |
898 | </para> | |
899 | </listitem> | |
900 | <listitem> | |
901 | <para> | |
902 | <option>proc:rw</option>: mount | |
903 | <filename>/proc</filename> as read-write | |
904 | </para> | |
905 | </listitem> | |
906 | <listitem> | |
907 | <para> | |
f24a52d5 SG |
908 | <option>sys:mixed</option> (or <option>sys</option>): |
909 | mount <filename>/sys</filename> as read-only but with | |
910 | /sys/devices/virtual/net writable. | |
911 | </para> | |
912 | </listitem> | |
913 | <listitem> | |
914 | <para> | |
915 | <option>sys:ro</option>: | |
c464fd7e SG |
916 | mount <filename>/sys</filename> as read-only |
917 | for security / container isolation purposes. | |
918 | </para> | |
919 | </listitem> | |
920 | <listitem> | |
921 | <para> | |
922 | <option>sys:rw</option>: mount | |
923 | <filename>/sys</filename> as read-write | |
924 | </para> | |
925 | </listitem> | |
926 | <listitem> | |
927 | <para> | |
928 | <option>cgroup:mixed</option>: | |
929 | mount a tmpfs to <filename>/sys/fs/cgroup</filename>, | |
930 | create directories for all hierarchies to which | |
931 | the container is added, create subdirectories | |
932 | there with the name of the cgroup, and bind-mount | |
933 | the container's own cgroup into that directory. | |
934 | The container will be able to write to its own | |
935 | cgroup directory, but not the parents, since they | |
4608594e | 936 | will be remounted read-only. |
c464fd7e SG |
937 | </para> |
938 | </listitem> | |
939 | <listitem> | |
940 | <para> | |
941 | <option>cgroup:ro</option>: similar to | |
942 | <option>cgroup:mixed</option>, but everything will | |
943 | be mounted read-only. | |
944 | </para> | |
945 | </listitem> | |
946 | <listitem> | |
947 | <para> | |
948 | <option>cgroup:rw</option>: similar to | |
949 | <option>cgroup:mixed</option>, but everything will | |
950 | be mounted read-write. Note that the paths leading | |
951 | up to the container's own cgroup will be writable, | |
952 | but will not be a cgroup filesystem but just part | |
953 | of the tmpfs of <filename>/sys/fs/cgroup</filename> | |
954 | </para> | |
955 | </listitem> | |
956 | <listitem> | |
957 | <para> | |
958 | <option>cgroup</option> (without specifier): | |
959 | defaults to <option>cgroup:rw</option> if the | |
960 | container retains the CAP_SYS_ADMIN capability, | |
961 | <option>cgroup:mixed</option> otherwise. | |
962 | </para> | |
963 | </listitem> | |
964 | <listitem> | |
965 | <para> | |
966 | <option>cgroup-full:mixed</option>: | |
967 | mount a tmpfs to <filename>/sys/fs/cgroup</filename>, | |
968 | create directories for all hierarchies to which | |
969 | the container is added, bind-mount the hierarchies | |
970 | from the host to the container and make everything | |
971 | read-only except the container's own cgroup. Note | |
972 | that compared to <option>cgroup</option>, where | |
973 | all paths leading up to the container's own cgroup | |
974 | are just simple directories in the underlying | |
975 | tmpfs, here | |
976 | <filename>/sys/fs/cgroup/$hierarchy</filename> | |
977 | will contain the host's full cgroup hierarchy, | |
978 | albeit read-only outside the container's own cgroup. | |
979 | This may leak quite a bit of information into the | |
980 | container. | |
981 | </para> | |
982 | </listitem> | |
983 | <listitem> | |
984 | <para> | |
985 | <option>cgroup-full:ro</option>: similar to | |
986 | <option>cgroup-full:mixed</option>, but everything | |
987 | will be mounted read-only. | |
988 | </para> | |
989 | </listitem> | |
990 | <listitem> | |
991 | <para> | |
992 | <option>cgroup-full:rw</option>: similar to | |
993 | <option>cgroup-full:mixed</option>, but everything | |
994 | will be mounted read-write. Note that in this case, | |
995 | the container may escape its own cgroup. (Note also | |
996 | that if the container has CAP_SYS_ADMIN support | |
997 | and can mount the cgroup filesystem itself, it may | |
998 | do so anyway.) | |
999 | </para> | |
1000 | </listitem> | |
1001 | <listitem> | |
1002 | <para> | |
1003 | <option>cgroup-full</option> (without specifier): | |
1004 | defaults to <option>cgroup-full:rw</option> if the | |
1005 | container retains the CAP_SYS_ADMIN capability, | |
1006 | <option>cgroup-full:mixed</option> otherwise. | |
1007 | </para> | |
1008 | </listitem> | |
1009 | </itemizedlist> | |
4608594e SH |
1010 | <para> |
1011 | If cgroup namespaces are enabled, then any <option>cgroup</option> | |
1012 | auto-mounting request will be ignored, since the container can | |
1013 | mount the filesystems itself, and automounting can confuse the | |
1014 | container init. | |
1015 | </para> | |
c464fd7e SG |
1016 | <para> |
1017 | Note that if automatic mounting of the cgroup filesystem | |
1018 | is enabled, the tmpfs under | |
1019 | <filename>/sys/fs/cgroup</filename> will always be | |
1020 | mounted read-write (but for the <option>:mixed</option> | |
1021 | and <option>:ro</option> cases, the individual | |
1022 | hierarchies, | |
1023 | <filename>/sys/fs/cgroup/$hierarchy</filename>, will be | |
1024 | read-only). This is in order to work around a quirk in | |
1025 | Ubuntu's | |
b46f0553 | 1026 | <citerefentry> |
c464fd7e | 1027 | <refentrytitle>mountall</refentrytitle> |
b46f0553 CS |
1028 | <manvolnum>8</manvolnum> |
1029 | </citerefentry> | |
c464fd7e SG |
1030 | command that will cause containers to wait for user |
1031 | input at boot if | |
1032 | <filename>/sys/fs/cgroup</filename> is mounted read-only | |
1033 | and the container can't remount it read-write due to a | |
1034 | lack of CAP_SYS_ADMIN. | |
1035 | </para> | |
1036 | <para> | |
1037 | Examples: | |
1038 | </para> | |
1039 | <programlisting> | |
1040 | lxc.mount.auto = proc sys cgroup | |
1041 | lxc.mount.auto = proc:rw sys:rw cgroup-full:rw | |
1042 | </programlisting> | |
1043 | </listitem> | |
1044 | </varlistentry> | |
55fc19a1 SG |
1045 | |
1046 | </variablelist> | |
1047 | </refsect2> | |
1048 | ||
1049 | <refsect2> | |
1050 | <title>Root file system</title> | |
1051 | <para> | |
c464fd7e SG |
1052 | The root file system of the container can be different than that |
1053 | of the host system. | |
55fc19a1 SG |
1054 | </para> |
1055 | <variablelist> | |
c464fd7e SG |
1056 | <varlistentry> |
1057 | <term> | |
7a96a068 | 1058 | <option>lxc.rootfs.path</option> |
c464fd7e SG |
1059 | </term> |
1060 | <listitem> | |
1061 | <para> | |
1062 | specify the root file system for the container. It can | |
1063 | be an image file, a directory or a block device. If not | |
1064 | specified, the container shares its root file system | |
1065 | with the host. | |
1066 | </para> | |
1067 | <para> | |
f1c26f2c SH |
1068 | For directory or simple block-device backed containers, |
1069 | a pathname can be used. If the rootfs is backed by a nbd | |
1070 | device, then <filename>nbd:file:1</filename> specifies that | |
1071 | <filename>file</filename> should be attached to a nbd device, | |
1072 | and partition 1 should be mounted as the rootfs. | |
1073 | <filename>nbd:file</filename> specifies that the nbd device | |
1074 | itself should be mounted. <filename>overlayfs:/lower:/upper</filename> | |
1075 | specifies that the rootfs should be an overlay with <filename>/upper</filename> | |
1076 | being mounted read-write over a read-only mount of <filename>/lower</filename>. | |
1077 | <filename>aufs:/lower:/upper</filename> does the same using aufs in place | |
280d2379 CB |
1078 | of overlayfs. For both <filename>overlayfs</filename> and |
1079 | <filename>aufs</filename> multiple <filename>/lower</filename> | |
1080 | directories can be specified. <filename>loop:/file</filename> tells lxc to attach | |
f1c26f2c | 1081 | <filename>/file</filename> to a loop device and mount the loop device. |
c464fd7e SG |
1082 | </para> |
1083 | </listitem> | |
1084 | </varlistentry> | |
1085 | ||
1086 | <varlistentry> | |
1087 | <term> | |
1088 | <option>lxc.rootfs.mount</option> | |
1089 | </term> | |
1090 | <listitem> | |
1091 | <para> | |
7a96a068 | 1092 | where to recursively bind <option>lxc.rootfs.path</option> |
c464fd7e SG |
1093 | before pivoting. This is to ensure success of the |
1094 | <citerefentry> | |
1095 | <refentrytitle><command>pivot_root</command></refentrytitle> | |
1096 | <manvolnum>8</manvolnum> | |
1097 | </citerefentry> | |
1098 | syscall. Any directory suffices, the default should | |
1099 | generally work. | |
1100 | </para> | |
1101 | </listitem> | |
1102 | </varlistentry> | |
1103 | ||
1104 | <varlistentry> | |
1105 | <term> | |
1106 | <option>lxc.rootfs.options</option> | |
1107 | </term> | |
1108 | <listitem> | |
1109 | <para> | |
1110 | extra mount options to use when mounting the rootfs. | |
1111 | </para> | |
1112 | </listitem> | |
1113 | </varlistentry> | |
a17b1e65 | 1114 | |
55fc19a1 SG |
1115 | </variablelist> |
1116 | </refsect2> | |
1117 | ||
1118 | <refsect2> | |
1119 | <title>Control group</title> | |
1120 | <para> | |
c464fd7e SG |
1121 | The control group section contains the configuration for the |
1122 | different subsystem. <command>lxc</command> does not check the | |
1123 | correctness of the subsystem name. This has the disadvantage | |
1124 | of not detecting configuration errors until the container is | |
1125 | started, but has the advantage of permitting any future | |
1126 | subsystem. | |
55fc19a1 SG |
1127 | </para> |
1128 | <variablelist> | |
c464fd7e SG |
1129 | <varlistentry> |
1130 | <term> | |
1131 | <option>lxc.cgroup.[subsystem name]</option> | |
1132 | </term> | |
1133 | <listitem> | |
1134 | <para> | |
1135 | specify the control group value to be set. The | |
1136 | subsystem name is the literal name of the control group | |
1137 | subsystem. The permitted names and the syntax of their | |
1138 | values is not dictated by LXC, instead it depends on the | |
1139 | features of the Linux kernel running at the time the | |
1140 | container is started, | |
1141 | eg. <option>lxc.cgroup.cpuset.cpus</option> | |
1142 | </para> | |
1143 | </listitem> | |
1144 | </varlistentry> | |
bdcbb6b3 CB |
1145 | <varlistentry> |
1146 | <term> | |
1147 | <option>lxc.cgroup.dir</option> | |
1148 | </term> | |
1149 | <listitem> | |
1150 | <para> | |
1151 | specify a directory or path in which the container's cgroup will | |
1152 | be created. For example, setting | |
1153 | <option>lxc.cgroup.dir = my-cgroup/first</option> for a container | |
1154 | named "c1" will create the container's cgroup as a sub-cgroup of | |
1155 | "my-cgroup". For example, if the user's current cgroup "my-user" | |
78be8d75 | 1156 | is located in the root cgroup of the cpuset controller in a |
bdcbb6b3 CB |
1157 | cgroup v1 hierarchy this would create the cgroup |
1158 | "/sys/fs/cgroup/cpuset/my-user/my-cgroup/first/c1" for the | |
1159 | container. Any missing cgroups will be created by LXC. This | |
1160 | presupposes that the user has write access to its current cgroup. | |
1161 | </para> | |
1162 | </listitem> | |
1163 | </varlistentry> | |
55fc19a1 SG |
1164 | </variablelist> |
1165 | </refsect2> | |
1166 | ||
1167 | <refsect2> | |
1168 | <title>Capabilities</title> | |
1169 | <para> | |
c464fd7e SG |
1170 | The capabilities can be dropped in the container if this one |
1171 | is run as root. | |
55fc19a1 SG |
1172 | </para> |
1173 | <variablelist> | |
c464fd7e SG |
1174 | <varlistentry> |
1175 | <term> | |
1176 | <option>lxc.cap.drop</option> | |
1177 | </term> | |
1178 | <listitem> | |
1179 | <para> | |
1180 | Specify the capability to be dropped in the container. A | |
1181 | single line defining several capabilities with a space | |
1182 | separation is allowed. The format is the lower case of | |
1183 | the capability definition without the "CAP_" prefix, | |
1184 | eg. CAP_SYS_MODULE should be specified as | |
1185 | sys_module. See | |
1186 | <citerefentry> | |
1187 | <refentrytitle><command>capabilities</command></refentrytitle> | |
1188 | <manvolnum>7</manvolnum> | |
7eff30fd MH |
1189 | </citerefentry>. |
1190 | If used with no value, lxc will clear any drop capabilities | |
1191 | specified up to this point. | |
c464fd7e SG |
1192 | </para> |
1193 | </listitem> | |
1194 | </varlistentry> | |
1195 | <varlistentry> | |
1196 | <term> | |
1197 | <option>lxc.cap.keep</option> | |
1198 | </term> | |
1199 | <listitem> | |
1200 | <para> | |
1201 | Specify the capability to be kept in the container. All other | |
1202 | capabilities will be dropped. When a special value of "none" is | |
1203 | encountered, lxc will clear any keep capabilities specified up | |
1204 | to this point. A value of "none" alone can be used to drop all | |
1205 | capabilities. | |
1206 | </para> | |
1207 | </listitem> | |
1208 | </varlistentry> | |
55fc19a1 SG |
1209 | </variablelist> |
1210 | </refsect2> | |
1211 | ||
93f9e90d WB |
1212 | <refsect2> |
1213 | <title>Resource limits</title> | |
1214 | <para> | |
1215 | The soft and hard resource limits for the container can be changed. | |
1216 | Unprivileged containers can only lower them. Resources which are not | |
1217 | explicitly specified will be inherited. | |
1218 | </para> | |
1219 | <variablelist> | |
1220 | <varlistentry> | |
1221 | <term> | |
240d4b74 | 1222 | <option>lxc.prlimit.[limit name]</option> |
93f9e90d WB |
1223 | </term> |
1224 | <listitem> | |
1225 | <para> | |
1226 | Specify the resource limit to be set. A limit is specified as two | |
1227 | colon separated values which are either numeric or the word | |
1228 | 'unlimited'. A single value can be used as a shortcut to set both | |
1229 | soft and hard limit to the same value. The permitted names the | |
1230 | "RLIMIT_" resource names in lowercase without the "RLIMIT_" | |
1231 | prefix, eg. RLIMIT_NOFILE should be specified as "nofile". See | |
1232 | <citerefentry> | |
1233 | <refentrytitle><command>setrlimit</command></refentrytitle> | |
1234 | <manvolnum>2</manvolnum> | |
1235 | </citerefentry>. | |
1236 | If used with no value, lxc will clear the resource limit | |
1237 | specified up to this point. A resource with no explicitly | |
1238 | configured limitation will be inherited from the process starting | |
1239 | up the container. | |
1240 | </para> | |
1241 | </listitem> | |
1242 | </varlistentry> | |
1243 | </variablelist> | |
1244 | </refsect2> | |
1245 | ||
55fc19a1 SG |
1246 | <refsect2> |
1247 | <title>Apparmor profile</title> | |
1248 | <para> | |
c464fd7e SG |
1249 | If lxc was compiled and installed with apparmor support, and the host |
1250 | system has apparmor enabled, then the apparmor profile under which the | |
1251 | container should be run can be specified in the container | |
7a126ae1 SH |
1252 | configuration. The default is <command>lxc-container-default-cgns</command> |
1253 | if the host kernel is cgroup namespace aware, or | |
1254 | <command>lxc-container-default</command> othewise. | |
55fc19a1 SG |
1255 | </para> |
1256 | <variablelist> | |
c464fd7e SG |
1257 | <varlistentry> |
1258 | <term> | |
a1d5fdfd | 1259 | <option>lxc.apparmor.profile</option> |
c464fd7e SG |
1260 | </term> |
1261 | <listitem> | |
1262 | <para> | |
1263 | Specify the apparmor profile under which the container should | |
1264 | be run. To specify that the container should be unconfined, | |
1265 | use | |
1266 | </para> | |
a1d5fdfd | 1267 | <programlisting>lxc.apparmor.profile = unconfined</programlisting> |
7a126ae1 SH |
1268 | <para> |
1269 | If the apparmor profile should remain unchanged (i.e. if you | |
1270 | are nesting containers and are already confined), then use | |
1271 | </para> | |
a1d5fdfd | 1272 | <programlisting>lxc.apparmor.profile = unchanged</programlisting> |
c464fd7e SG |
1273 | </listitem> |
1274 | </varlistentry> | |
1275 | <varlistentry> | |
1276 | <term> | |
69e38e00 | 1277 | <option>lxc.apparmor.allow_incomplete</option> |
c464fd7e SG |
1278 | </term> |
1279 | <listitem> | |
1280 | <para> | |
1281 | Apparmor profiles are pathname based. Therefore many file | |
1282 | restrictions require mount restrictions to be effective against | |
1283 | a determined attacker. However, these mount restrictions are not | |
1284 | yet implemented in the upstream kernel. Without the mount | |
1285 | restrictions, the apparmor profiles still protect against accidental | |
1286 | damager. | |
1287 | </para> | |
1288 | <para> | |
1289 | If this flag is 0 (default), then the container will not be | |
1290 | started if the kernel lacks the apparmor mount features, so that a | |
1291 | regression after a kernel upgrade will be detected. To start the | |
1292 | container under partial apparmor protection, set this flag to 1. | |
1293 | </para> | |
1294 | </listitem> | |
1295 | </varlistentry> | |
55fc19a1 SG |
1296 | </variablelist> |
1297 | </refsect2> | |
1298 | ||
1299 | <refsect2> | |
1300 | <title>SELinux context</title> | |
1301 | <para> | |
c464fd7e SG |
1302 | If lxc was compiled and installed with SELinux support, and the host |
1303 | system has SELinux enabled, then the SELinux context under which the | |
1304 | container should be run can be specified in the container | |
1305 | configuration. The default is <command>unconfined_t</command>, | |
1306 | which means that lxc will not attempt to change contexts. | |
1307 | See @DATADIR@/lxc/selinux/lxc.te for an example policy and more | |
1308 | information. | |
55fc19a1 SG |
1309 | </para> |
1310 | <variablelist> | |
c464fd7e SG |
1311 | <varlistentry> |
1312 | <term> | |
b84702ab | 1313 | <option>lxc.selinux.context</option> |
c464fd7e SG |
1314 | </term> |
1315 | <listitem> | |
1316 | <para> | |
1317 | Specify the SELinux context under which the container should | |
1318 | be run or <command>unconfined_t</command>. For example | |
1319 | </para> | |
b84702ab | 1320 | <programlisting>lxc.selinux.context = system_u:system_r:lxc_t:s0:c22</programlisting> |
c464fd7e SG |
1321 | </listitem> |
1322 | </varlistentry> | |
55fc19a1 SG |
1323 | </variablelist> |
1324 | </refsect2> | |
1325 | ||
1326 | <refsect2> | |
1327 | <title>Seccomp configuration</title> | |
1328 | <para> | |
1329 | A container can be started with a reduced set of available | |
c464fd7e SG |
1330 | system calls by loading a seccomp profile at startup. The |
1331 | seccomp configuration file must begin with a version number | |
1332 | on the first line, a policy type on the second line, followed | |
1333 | by the configuration. | |
55fc19a1 | 1334 | </para> |
a7c27357 SH |
1335 | <para> |
1336 | Versions 1 and 2 are currently supported. In version 1, the | |
c464fd7e SG |
1337 | policy is a simple whitelist. The second line therefore must |
1338 | read "whitelist", with the rest of the file containing one (numeric) | |
1339 | sycall number per line. Each syscall number is whitelisted, | |
1340 | while every unlisted number is blacklisted for use in the container | |
a7c27357 SH |
1341 | </para> |
1342 | ||
1343 | <para> | |
1344 | In version 2, the policy may be blacklist or whitelist, | |
1345 | supports per-rule and per-policy default actions, and supports | |
1346 | per-architecture system call resolution from textual names. | |
1347 | </para> | |
1348 | <para> | |
1349 | An example blacklist policy, in which all system calls are | |
1350 | allowed except for mknod, which will simply do nothing and | |
1351 | return 0 (success), looks like: | |
1352 | </para> | |
b9986e43 CB |
1353 | |
1354 | <programlisting> | |
1355 | 2 | |
1356 | blacklist | |
1357 | mknod errno 0 | |
1358 | </programlisting> | |
1359 | ||
55fc19a1 | 1360 | <variablelist> |
c464fd7e SG |
1361 | <varlistentry> |
1362 | <term> | |
0b427da0 | 1363 | <option>lxc.seccomp.profile</option> |
c464fd7e SG |
1364 | </term> |
1365 | <listitem> | |
1366 | <para> | |
1367 | Specify a file containing the seccomp configuration to | |
1368 | load before the container starts. | |
1369 | </para> | |
1370 | </listitem> | |
1371 | </varlistentry> | |
55fc19a1 SG |
1372 | </variablelist> |
1373 | </refsect2> | |
1374 | ||
222ddc91 CB |
1375 | <refsect2> |
1376 | <title>PR_SET_NO_NEW_PRIVS</title> | |
1377 | <para> | |
1378 | With PR_SET_NO_NEW_PRIVS active execve() promises not to grant | |
1379 | privileges to do anything that could not have been done without | |
1380 | the execve() call (for example, rendering the set-user-ID and | |
1381 | set-group-ID mode bits, and file capabilities non-functional). | |
1382 | Once set, this bit cannot be unset. The setting of this bit is | |
1383 | inherited by children created by fork() and clone(), and preserved | |
1384 | across execve(). | |
1385 | Note that PR_SET_NO_NEW_PRIVS is applied after the container has | |
1386 | changed into its intended AppArmor profile or SElinux context. | |
1387 | </para> | |
1388 | <variablelist> | |
1389 | <varlistentry> | |
1390 | <term> | |
1391 | <option>lxc.no_new_privs</option> | |
1392 | </term> | |
1393 | <listitem> | |
1394 | <para> | |
1395 | Specify whether the PR_SET_NO_NEW_PRIVS flag should be set for the | |
1396 | container. Set to 1 to activate. | |
1397 | </para> | |
1398 | </listitem> | |
1399 | </varlistentry> | |
1400 | </variablelist> | |
1401 | </refsect2> | |
1402 | ||
55fc19a1 SG |
1403 | <refsect2> |
1404 | <title>UID mappings</title> | |
1405 | <para> | |
1406 | A container can be started in a private user namespace with | |
c464fd7e SG |
1407 | user and group id mappings. For instance, you can map userid |
1408 | 0 in the container to userid 200000 on the host. The root | |
1409 | user in the container will be privileged in the container, | |
1410 | but unprivileged on the host. Normally a system container | |
1411 | will want a range of ids, so you would map, for instance, | |
1412 | user and group ids 0 through 20,000 in the container to the | |
1413 | ids 200,000 through 220,000. | |
55fc19a1 SG |
1414 | </para> |
1415 | <variablelist> | |
c464fd7e SG |
1416 | <varlistentry> |
1417 | <term> | |
bdcbb6b3 | 1418 | <option>lxc.idmap</option> |
c464fd7e SG |
1419 | </term> |
1420 | <listitem> | |
1421 | <para> | |
1422 | Four values must be provided. First a character, either | |
1423 | 'u', or 'g', to specify whether user or group ids are | |
1424 | being mapped. Next is the first userid as seen in the | |
1425 | user namespace of the container. Next is the userid as | |
1426 | seen on the host. Finally, a range indicating the number | |
1427 | of consecutive ids to map. | |
1428 | </para> | |
1429 | </listitem> | |
1430 | </varlistentry> | |
55fc19a1 SG |
1431 | </variablelist> |
1432 | </refsect2> | |
1433 | ||
1434 | <refsect2> | |
1435 | <title>Container hooks</title> | |
1436 | <para> | |
1437 | Container hooks are programs or scripts which can be executed | |
c464fd7e | 1438 | at various times in a container's lifetime. |
55fc19a1 SG |
1439 | </para> |
1440 | <para> | |
1441 | When a container hook is executed, information is passed both | |
c464fd7e SG |
1442 | as command line arguments and through environment variables. |
1443 | The arguments are: | |
1444 | <itemizedlist> | |
1445 | <listitem><para> Container name. </para></listitem> | |
1446 | <listitem><para> Section (always 'lxc'). </para></listitem> | |
1447 | <listitem><para> The hook type (i.e. 'clone' or 'pre-mount'). </para></listitem> | |
0a2b5ab1 | 1448 | <listitem><para> Additional arguments. In the |
c464fd7e | 1449 | case of the clone hook, any extra arguments passed to |
0a2b5ab1 WB |
1450 | lxc-clone will appear as further arguments to the hook. |
1451 | In the case of the stop hook, paths to filedescriptors | |
1452 | for each of the container's namespaces along with their types | |
1453 | are passed. </para></listitem> | |
c464fd7e SG |
1454 | </itemizedlist> |
1455 | The following environment variables are set: | |
1456 | <itemizedlist> | |
1457 | <listitem><para> LXC_NAME: is the container's name. </para></listitem> | |
1458 | <listitem><para> LXC_ROOTFS_MOUNT: the path to the mounted root filesystem. </para></listitem> | |
1459 | <listitem><para> LXC_CONFIG_FILE: the path to the container configuration file. </para></listitem> | |
1460 | <listitem><para> LXC_SRC_NAME: in the case of the clone hook, this is the original container's name. </para></listitem> | |
7a96a068 | 1461 | <listitem><para> LXC_ROOTFS_PATH: this is the lxc.rootfs.path entry for the container. Note this is likely not where the mounted rootfs is to be found, use LXC_ROOTFS_MOUNT for that. </para></listitem> |
b68c6a71 CB |
1462 | <listitem><para> LXC_CGNS_AWARE: indicated whether the container is cgroup namespace aware. </para></listitem> |
1463 | <listitem><para> LXC_LOG_LEVEL: the container's log level. </para></listitem> | |
c464fd7e | 1464 | </itemizedlist> |
55fc19a1 SG |
1465 | </para> |
1466 | <para> | |
1467 | Standard output from the hooks is logged at debug level. | |
1468 | Standard error is not logged, but can be captured by the | |
1469 | hook redirecting its standard error to standard output. | |
1470 | </para> | |
1471 | <variablelist> | |
c464fd7e SG |
1472 | <varlistentry> |
1473 | <term> | |
1474 | <option>lxc.hook.pre-start</option> | |
1475 | </term> | |
1476 | <listitem> | |
1477 | <para> | |
1478 | A hook to be run in the host's namespace before the | |
1479 | container ttys, consoles, or mounts are up. | |
1480 | </para> | |
1481 | </listitem> | |
1482 | </varlistentry> | |
55fc19a1 SG |
1483 | </variablelist> |
1484 | <variablelist> | |
c464fd7e SG |
1485 | <varlistentry> |
1486 | <term> | |
1487 | <option>lxc.hook.pre-mount</option> | |
1488 | </term> | |
1489 | <listitem> | |
1490 | <para> | |
1491 | A hook to be run in the container's fs namespace but before | |
1492 | the rootfs has been set up. This allows for manipulation | |
1493 | of the rootfs, i.e. to mount an encrypted filesystem. Mounts | |
1494 | done in this hook will not be reflected on the host (apart from | |
1495 | mounts propagation), so they will be automatically cleaned up | |
1496 | when the container shuts down. | |
1497 | </para> | |
1498 | </listitem> | |
1499 | </varlistentry> | |
55fc19a1 SG |
1500 | </variablelist> |
1501 | <variablelist> | |
c464fd7e SG |
1502 | <varlistentry> |
1503 | <term> | |
1504 | <option>lxc.hook.mount</option> | |
1505 | </term> | |
1506 | <listitem> | |
1507 | <para> | |
1508 | A hook to be run in the container's namespace after | |
1509 | mounting has been done, but before the pivot_root. | |
1510 | </para> | |
1511 | </listitem> | |
1512 | </varlistentry> | |
55fc19a1 SG |
1513 | </variablelist> |
1514 | <variablelist> | |
c464fd7e SG |
1515 | <varlistentry> |
1516 | <term> | |
1517 | <option>lxc.hook.autodev</option> | |
1518 | </term> | |
1519 | <listitem> | |
1520 | <para> | |
1521 | A hook to be run in the container's namespace after | |
1522 | mounting has been done and after any mount hooks have | |
1523 | run, but before the pivot_root, if | |
1524 | <option>lxc.autodev</option> == 1. | |
1525 | The purpose of this hook is to assist in populating the | |
1526 | /dev directory of the container when using the autodev | |
1527 | option for systemd based containers. The container's /dev | |
1528 | directory is relative to the | |
1529 | ${<option>LXC_ROOTFS_MOUNT</option>} environment | |
1530 | variable available when the hook is run. | |
1531 | </para> | |
1532 | </listitem> | |
1533 | </varlistentry> | |
55fc19a1 | 1534 | </variablelist> |
08dd2805 SH |
1535 | <variablelist> |
1536 | <varlistentry> | |
1537 | <term> | |
1538 | <option>lxc.hook.start-host</option> | |
1539 | </term> | |
1540 | <listitem> | |
1541 | <para> | |
1542 | A hook to be run in the host's namespace after the | |
1543 | container has been setup, and immediately before starting | |
1544 | the container init. | |
1545 | </para> | |
1546 | </listitem> | |
1547 | </varlistentry> | |
1548 | </variablelist> | |
55fc19a1 | 1549 | <variablelist> |
c464fd7e SG |
1550 | <varlistentry> |
1551 | <term> | |
1552 | <option>lxc.hook.start</option> | |
1553 | </term> | |
1554 | <listitem> | |
1555 | <para> | |
1556 | A hook to be run in the container's namespace immediately | |
1557 | before executing the container's init. This requires the | |
1558 | program to be available in the container. | |
1559 | </para> | |
1560 | </listitem> | |
1561 | </varlistentry> | |
55fc19a1 | 1562 | </variablelist> |
0a2b5ab1 WB |
1563 | <variablelist> |
1564 | <varlistentry> | |
1565 | <term> | |
1566 | <option>lxc.hook.stop</option> | |
1567 | </term> | |
1568 | <listitem> | |
1569 | <para> | |
1570 | A hook to be run in the host's namespace with references | |
1571 | to the container's namespaces after the container has been shut | |
1572 | down. For each namespace an extra argument is passed to the hook | |
1573 | containing the namespace's type and a filename that can be used to | |
1574 | obtain a file descriptor to the corresponding namespace, separated | |
1575 | by a colon. The type is the name as it would appear in the | |
1576 | <filename>/proc/PID/ns</filename> directory. | |
1577 | For instance for the mount namespace the argument usually looks | |
1578 | like <filename>mnt:/proc/PID/fd/12</filename>. | |
1579 | </para> | |
1580 | </listitem> | |
1581 | </varlistentry> | |
1582 | </variablelist> | |
55fc19a1 | 1583 | <variablelist> |
c464fd7e SG |
1584 | <varlistentry> |
1585 | <term> | |
1586 | <option>lxc.hook.post-stop</option> | |
1587 | </term> | |
1588 | <listitem> | |
1589 | <para> | |
1590 | A hook to be run in the host's namespace after the | |
1591 | container has been shut down. | |
1592 | </para> | |
1593 | </listitem> | |
1594 | </varlistentry> | |
55fc19a1 SG |
1595 | </variablelist> |
1596 | <variablelist> | |
c464fd7e SG |
1597 | <varlistentry> |
1598 | <term> | |
1599 | <option>lxc.hook.clone</option> | |
1600 | </term> | |
1601 | <listitem> | |
1602 | <para> | |
1603 | A hook to be run when the container is cloned to a new one. | |
1604 | See <citerefentry><refentrytitle><command>lxc-clone</command></refentrytitle> | |
1605 | <manvolnum>1</manvolnum></citerefentry> for more information. | |
1606 | </para> | |
1607 | </listitem> | |
1608 | </varlistentry> | |
55fc19a1 | 1609 | </variablelist> |
37cf711b SY |
1610 | <variablelist> |
1611 | <varlistentry> | |
1612 | <term> | |
1613 | <option>lxc.hook.destroy</option> | |
1614 | </term> | |
1615 | <listitem> | |
1616 | <para> | |
1617 | A hook to be run when the container is destroyed. | |
1618 | </para> | |
1619 | </listitem> | |
1620 | </varlistentry> | |
1621 | </variablelist> | |
55fc19a1 SG |
1622 | </refsect2> |
1623 | ||
1624 | <refsect2> | |
1625 | <title>Container hooks Environment Variables</title> | |
1626 | <para> | |
1627 | A number of environment variables are made available to the startup | |
1628 | hooks to provide configuration information and assist in the | |
1629 | functioning of the hooks. Not all variables are valid in all | |
1630 | contexts. In particular, all paths are relative to the host system | |
1631 | and, as such, not valid during the <option>lxc.hook.start</option> hook. | |
1632 | </para> | |
1633 | <variablelist> | |
c464fd7e SG |
1634 | <varlistentry> |
1635 | <term> | |
1636 | <option>LXC_NAME</option> | |
1637 | </term> | |
1638 | <listitem> | |
1639 | <para> | |
1640 | The LXC name of the container. Useful for logging messages | |
1641 | in common log environments. [<option>-n</option>] | |
1642 | </para> | |
1643 | </listitem> | |
1644 | </varlistentry> | |
55fc19a1 SG |
1645 | </variablelist> |
1646 | <variablelist> | |
c464fd7e SG |
1647 | <varlistentry> |
1648 | <term> | |
1649 | <option>LXC_CONFIG_FILE</option> | |
1650 | </term> | |
1651 | <listitem> | |
1652 | <para> | |
1653 | Host relative path to the container configuration file. This | |
1654 | gives the container to reference the original, top level, | |
1655 | configuration file for the container in order to locate any | |
1656 | additional configuration information not otherwise made | |
1657 | available. [<option>-f</option>] | |
1658 | </para> | |
1659 | </listitem> | |
1660 | </varlistentry> | |
55fc19a1 SG |
1661 | </variablelist> |
1662 | <variablelist> | |
c464fd7e SG |
1663 | <varlistentry> |
1664 | <term> | |
1665 | <option>LXC_CONSOLE</option> | |
1666 | </term> | |
1667 | <listitem> | |
1668 | <para> | |
1669 | The path to the console output of the container if not NULL. | |
3aed4934 | 1670 | [<option>-c</option>] [<option>lxc.console.path</option>] |
c464fd7e SG |
1671 | </para> |
1672 | </listitem> | |
1673 | </varlistentry> | |
55fc19a1 SG |
1674 | </variablelist> |
1675 | <variablelist> | |
c464fd7e SG |
1676 | <varlistentry> |
1677 | <term> | |
1678 | <option>LXC_CONSOLE_LOGPATH</option> | |
1679 | </term> | |
1680 | <listitem> | |
1681 | <para> | |
1682 | The path to the console log output of the container if not NULL. | |
1683 | [<option>-L</option>] | |
1684 | </para> | |
1685 | </listitem> | |
1686 | </varlistentry> | |
55fc19a1 SG |
1687 | </variablelist> |
1688 | <variablelist> | |
c464fd7e SG |
1689 | <varlistentry> |
1690 | <term> | |
1691 | <option>LXC_ROOTFS_MOUNT</option> | |
1692 | </term> | |
1693 | <listitem> | |
1694 | <para> | |
1695 | The mount location to which the container is initially bound. | |
1696 | This will be the host relative path to the container rootfs | |
1697 | for the container instance being started and is where changes | |
1698 | should be made for that instance. | |
1699 | [<option>lxc.rootfs.mount</option>] | |
1700 | </para> | |
1701 | </listitem> | |
1702 | </varlistentry> | |
55fc19a1 SG |
1703 | </variablelist> |
1704 | <variablelist> | |
c464fd7e SG |
1705 | <varlistentry> |
1706 | <term> | |
1707 | <option>LXC_ROOTFS_PATH</option> | |
1708 | </term> | |
1709 | <listitem> | |
1710 | <para> | |
1711 | The host relative path to the container root which has been | |
1712 | mounted to the rootfs.mount location. | |
7a96a068 | 1713 | [<option>lxc.rootfs.path</option>] |
c464fd7e SG |
1714 | </para> |
1715 | </listitem> | |
1716 | </varlistentry> | |
55fc19a1 | 1717 | </variablelist> |
07945418 KY |
1718 | <variablelist> |
1719 | <varlistentry> | |
1720 | <term> | |
1721 | <option>LXC_SRC_NAME</option> | |
1722 | </term> | |
1723 | <listitem> | |
1724 | <para> | |
1725 | Only for the clone hook. Is set to the original container name. | |
1726 | </para> | |
1727 | </listitem> | |
1728 | </varlistentry> | |
1729 | </variablelist> | |
c154af98 SG |
1730 | <variablelist> |
1731 | <varlistentry> | |
1732 | <term> | |
1733 | <option>LXC_TARGET</option> | |
1734 | </term> | |
1735 | <listitem> | |
1736 | <para> | |
1737 | Only for the stop hook. Is set to "stop" for a container | |
1738 | shutdown or "reboot" for a container reboot. | |
1739 | </para> | |
1740 | </listitem> | |
1741 | </varlistentry> | |
c4cafa08 SH |
1742 | </variablelist> |
1743 | <variablelist> | |
1744 | <varlistentry> | |
1745 | <term> | |
1746 | <option>LXC_CGNS_AWARE</option> | |
1747 | </term> | |
1748 | <listitem> | |
1749 | <para> | |
1750 | If unset, then this version of lxc is not aware of cgroup | |
1751 | namespaces. If set, it will be set to 1, and lxc is aware | |
1752 | of cgroup namespaces. Note this does not guarantee that | |
1753 | cgroup namespaces are enabled in the kernel. This is used | |
1754 | by the lxcfs mount hook. | |
1755 | </para> | |
1756 | </listitem> | |
1757 | </varlistentry> | |
c154af98 | 1758 | </variablelist> |
55fc19a1 SG |
1759 | </refsect2> |
1760 | <refsect2> | |
1761 | <title>Logging</title> | |
1762 | <para> | |
1763 | Logging can be configured on a per-container basis. By default, | |
1764 | depending upon how the lxc package was compiled, container startup | |
1765 | is logged only at the ERROR level, and logged to a file named after | |
1766 | the container (with '.log' appended) either under the container path, | |
1767 | or under @LOGPATH@. | |
1768 | </para> | |
1769 | <para> | |
1770 | Both the default log level and the log file can be specified in the | |
1771 | container configuration file, overriding the default behavior. Note | |
1772 | that the configuration file entries can in turn be overridden by the | |
1773 | command line options to <command>lxc-start</command>. | |
1774 | </para> | |
1775 | <variablelist> | |
c464fd7e SG |
1776 | <varlistentry> |
1777 | <term> | |
46cc906d | 1778 | <option>lxc.log.level</option> |
c464fd7e SG |
1779 | </term> |
1780 | <listitem> | |
1781 | <para> | |
1782 | The level at which to log. The log level is an integer in | |
1783 | the range of 0..8 inclusive, where a lower number means more | |
1784 | verbose debugging. In particular 0 = trace, 1 = debug, 2 = | |
1785 | info, 3 = notice, 4 = warn, 5 = error, 6 = critical, 7 = | |
1786 | alert, and 8 = fatal. If unspecified, the level defaults | |
1787 | to 5 (error), so that only errors and above are logged. | |
1788 | </para> | |
1789 | <para> | |
1790 | Note that when a script (such as either a hook script or a | |
1791 | network interface up or down script) is called, the script's | |
1792 | standard output is logged at level 1, debug. | |
1793 | </para> | |
1794 | </listitem> | |
1795 | </varlistentry> | |
1796 | <varlistentry> | |
1797 | <term> | |
46cc906d | 1798 | <option>lxc.log</option> |
c464fd7e SG |
1799 | </term> |
1800 | <listitem> | |
1801 | <para> | |
1802 | The file to which logging info should be written. | |
1803 | </para> | |
1804 | </listitem> | |
1805 | </varlistentry> | |
204dfdf2 BD |
1806 | <varlistentry> |
1807 | <term> | |
46cc906d | 1808 | <option>lxc.log.syslog</option> |
204dfdf2 BD |
1809 | </term> |
1810 | <listitem> | |
1811 | <para> | |
1812 | Send logging info to syslog. It respects the log level defined in | |
46cc906d | 1813 | <command>lxc.log.level</command>. The argument should be the syslog |
204dfdf2 | 1814 | facility to use, valid ones are: daemon, local0, local1, local2, |
917420dd | 1815 | local3, local4, local5, local5, local6, local7. |
204dfdf2 BD |
1816 | </para> |
1817 | </listitem> | |
1818 | </varlistentry> | |
55fc19a1 SG |
1819 | </variablelist> |
1820 | </refsect2> | |
1821 | ||
1822 | <refsect2> | |
1823 | <title>Autostart</title> | |
1824 | <para> | |
1825 | The autostart options support marking which containers should be | |
1826 | auto-started and in what order. These options may be used by LXC tools | |
1827 | directly or by external tooling provided by the distributions. | |
1828 | </para> | |
1829 | ||
1830 | <variablelist> | |
1831 | <varlistentry> | |
1832 | <term> | |
1833 | <option>lxc.start.auto</option> | |
1834 | </term> | |
1835 | <listitem> | |
1836 | <para> | |
1837 | Whether the container should be auto-started. | |
1838 | Valid values are 0 (off) and 1 (on). | |
1839 | </para> | |
1840 | </listitem> | |
1841 | </varlistentry> | |
1842 | <varlistentry> | |
1843 | <term> | |
1844 | <option>lxc.start.delay</option> | |
1845 | </term> | |
1846 | <listitem> | |
1847 | <para> | |
1848 | How long to wait (in seconds) after the container is | |
1849 | started before starting the next one. | |
1850 | </para> | |
1851 | </listitem> | |
1852 | </varlistentry> | |
1853 | <varlistentry> | |
1854 | <term> | |
1855 | <option>lxc.start.order</option> | |
1856 | </term> | |
1857 | <listitem> | |
1858 | <para> | |
1859 | An integer used to sort the containers when auto-starting | |
1860 | a series of containers at once. | |
1861 | </para> | |
1862 | </listitem> | |
1863 | </varlistentry> | |
a8dfe4e0 WB |
1864 | <varlistentry> |
1865 | <term> | |
1866 | <option>lxc.monitor.unshare</option> | |
1867 | </term> | |
1868 | <listitem> | |
1869 | <para> | |
1870 | If not zero the mount namespace will be unshared from the host | |
1871 | before initializing the container (before running any pre-start | |
6039eaa2 WB |
1872 | hooks). This requires the CAP_SYS_ADMIN capability at startup. |
1873 | Default is 0. | |
a8dfe4e0 WB |
1874 | </para> |
1875 | </listitem> | |
1876 | </varlistentry> | |
55fc19a1 SG |
1877 | <varlistentry> |
1878 | <term> | |
1879 | <option>lxc.group</option> | |
1880 | </term> | |
1881 | <listitem> | |
1882 | <para> | |
1883 | A multi-value key (can be used multiple times) to put the | |
1884 | container in a container group. Those groups can then be | |
1885 | used (amongst other things) to start a series of related | |
1886 | containers. | |
1887 | </para> | |
1888 | </listitem> | |
1889 | </varlistentry> | |
1890 | </variablelist> | |
1891 | </refsect2> | |
015f0dd7 MW |
1892 | |
1893 | <refsect2> | |
1894 | <title>Autostart and System Boot</title> | |
1895 | <para> | |
1896 | Each container can be part of any number of groups or no group at all. | |
1897 | Two groups are special. One is the NULL group, i.e. the container does | |
1898 | not belong to any group. The other group is the "onboot" group. | |
1899 | </para> | |
1900 | ||
1901 | <para> | |
1902 | When the system boots with the LXC service enabled, it will first | |
1903 | attempt to boot any containers with lxc.start.auto == 1 that is a member | |
1904 | of the "onboot" group. The startup will be in order of lxc.start.order. | |
1905 | If an lxc.start.delay has been specified, that delay will be honored | |
1906 | before attempting to start the next container to give the current | |
1907 | container time to begin initialization and reduce overloading the host | |
1908 | system. After starting the members of the "onboot" group, the LXC system | |
1909 | will proceed to boot containers with lxc.start.auto == 1 which are not | |
1910 | members of any group (the NULL group) and proceed as with the onboot | |
1911 | group. | |
1912 | </para> | |
1913 | ||
1914 | </refsect2> | |
7c661726 MP |
1915 | |
1916 | <refsect2> | |
1917 | <title>Container Environment</title> | |
1918 | <para> | |
c464fd7e SG |
1919 | If you want to pass environment variables into the container (that |
1920 | is, environment variables which will be available to init and all of | |
1921 | its descendents), you can use <command>lxc.environment</command> | |
1922 | parameters to do so. Be careful that you do not pass in anything | |
1923 | sensitive; any process in the container which doesn't have its | |
1924 | environment scrubbed will have these variables available to it, and | |
1925 | environment variables are always available via | |
1926 | <command>/proc/PID/environ</command>. | |
7c661726 MP |
1927 | </para> |
1928 | ||
1929 | <para> | |
1930 | This configuration parameter can be specified multiple times; once | |
1931 | for each environment variable you wish to configure. | |
1932 | </para> | |
1933 | ||
1934 | <variablelist> | |
c464fd7e SG |
1935 | <varlistentry> |
1936 | <term> | |
1937 | <option>lxc.environment</option> | |
1938 | </term> | |
1939 | <listitem> | |
1940 | <para> | |
1941 | Specify an environment variable to pass into the container. | |
1942 | Example: | |
1943 | </para> | |
1944 | <programlisting> | |
1945 | lxc.environment = APP_ENV=production | |
1946 | lxc.environment = SYSLOG_SERVER=192.0.2.42 | |
1947 | </programlisting> | |
1948 | </listitem> | |
1949 | </varlistentry> | |
7c661726 MP |
1950 | </variablelist> |
1951 | </refsect2> | |
1952 | ||
55fc19a1 SG |
1953 | </refsect1> |
1954 | ||
1955 | <refsect1> | |
1956 | <title>Examples</title> | |
1957 | <para> | |
c464fd7e SG |
1958 | In addition to the few examples given below, you will find |
1959 | some other examples of configuration file in @DOCDIR@/examples | |
55fc19a1 SG |
1960 | </para> |
1961 | <refsect2> | |
1962 | <title>Network</title> | |
1963 | <para>This configuration sets up a container to use a veth pair | |
c464fd7e SG |
1964 | device with one side plugged to a bridge br0 (which has been |
1965 | configured before on the system by the administrator). The | |
1966 | virtual network device visible in the container is renamed to | |
1967 | eth0.</para> | |
55fc19a1 | 1968 | <programlisting> |
b67771bc | 1969 | lxc.uts.name = myhostname |
7fa3f2e9 | 1970 | lxc.net.0.type = veth |
1971 | lxc.net.0.flags = up | |
1972 | lxc.net.0.link = br0 | |
1973 | lxc.net.0.name = eth0 | |
1974 | lxc.net.0.hwaddr = 4a:49:43:49:79:bf | |
9ff60df2 | 1975 | lxc.net.0.ipv4.address = 10.2.3.5/24 10.2.3.255 |
2e44ae28 | 1976 | lxc.net.0.ipv6.address = 2003:db8:1:0:214:1234:fe0b:3597 |
55fc19a1 SG |
1977 | </programlisting> |
1978 | </refsect2> | |
1979 | ||
1980 | <refsect2> | |
1981 | <title>UID/GID mapping</title> | |
1982 | <para>This configuration will map both user and group ids in the | |
1983 | range 0-9999 in the container to the ids 100000-109999 on the host. | |
1984 | </para> | |
1985 | <programlisting> | |
bdcbb6b3 CB |
1986 | lxc.idmap = u 0 100000 10000 |
1987 | lxc.idmap = g 0 100000 10000 | |
55fc19a1 SG |
1988 | </programlisting> |
1989 | </refsect2> | |
1990 | ||
1991 | <refsect2> | |
1992 | <title>Control group</title> | |
1993 | <para>This configuration will setup several control groups for | |
1994 | the application, cpuset.cpus restricts usage of the defined cpu, | |
1995 | cpus.share prioritize the control group, devices.allow makes | |
1996 | usable the specified devices.</para> | |
1997 | <programlisting> | |
c464fd7e SG |
1998 | lxc.cgroup.cpuset.cpus = 0,1 |
1999 | lxc.cgroup.cpu.shares = 1234 | |
2000 | lxc.cgroup.devices.deny = a | |
2001 | lxc.cgroup.devices.allow = c 1:3 rw | |
2002 | lxc.cgroup.devices.allow = b 8:0 rw | |
55fc19a1 SG |
2003 | </programlisting> |
2004 | </refsect2> | |
2005 | ||
2006 | <refsect2> | |
2007 | <title>Complex configuration</title> | |
2008 | <para>This example show a complex configuration making a complex | |
2009 | network stack, using the control groups, setting a new hostname, | |
2010 | mounting some locations and a changing root file system.</para> | |
2011 | <programlisting> | |
b67771bc | 2012 | lxc.uts.name = complex |
7fa3f2e9 | 2013 | lxc.net.0.type = veth |
2014 | lxc.net.0.flags = up | |
2015 | lxc.net.0.link = br0 | |
2016 | lxc.net.0.hwaddr = 4a:49:43:49:79:bf | |
9ff60df2 | 2017 | lxc.net.0.ipv4.address = 10.2.3.5/24 10.2.3.255 |
2e44ae28 CB |
2018 | lxc.net.0.ipv6.address = 2003:db8:1:0:214:1234:fe0b:3597 |
2019 | lxc.net.0.ipv6.address = 2003:db8:1:0:214:5432:feab:3588 | |
7fa3f2e9 | 2020 | lxc.net.1.type = macvlan |
2021 | lxc.net.1.flags = up | |
2022 | lxc.net.1.link = eth0 | |
2023 | lxc.net.1.hwaddr = 4a:49:43:49:79:bd | |
9ff60df2 CB |
2024 | lxc.net.1.ipv4.address = 10.2.3.4/24 |
2025 | lxc.net.1.ipv4.address = 192.168.10.125/24 | |
2e44ae28 | 2026 | lxc.net.1.ipv6.address = 2003:db8:1:0:214:1234:fe0b:3596 |
7fa3f2e9 | 2027 | lxc.net.2.type = phys |
2028 | lxc.net.2.flags = up | |
2029 | lxc.net.2.link = dummy0 | |
2030 | lxc.net.2.hwaddr = 4a:49:43:49:79:ff | |
9ff60df2 | 2031 | lxc.net.2.ipv4.address = 10.2.3.6/24 |
2e44ae28 | 2032 | lxc.net.2.ipv6.address = 2003:db8:1:0:214:1234:fe0b:3297 |
c464fd7e SG |
2033 | lxc.cgroup.cpuset.cpus = 0,1 |
2034 | lxc.cgroup.cpu.shares = 1234 | |
2035 | lxc.cgroup.devices.deny = a | |
2036 | lxc.cgroup.devices.allow = c 1:3 rw | |
2037 | lxc.cgroup.devices.allow = b 8:0 rw | |
47148e96 | 2038 | lxc.mount.fstab = /etc/fstab.complex |
c464fd7e | 2039 | lxc.mount.entry = /lib /root/myrootfs/lib none ro,bind 0 0 |
7a96a068 | 2040 | lxc.rootfs.path = dir:/mnt/rootfs.complex |
c464fd7e SG |
2041 | lxc.cap.drop = sys_module mknod setuid net_raw |
2042 | lxc.cap.drop = mac_override | |
55fc19a1 SG |
2043 | </programlisting> |
2044 | </refsect2> | |
2045 | ||
2046 | </refsect1> | |
2047 | ||
2048 | <refsect1> | |
2049 | <title>See Also</title> | |
2050 | <simpara> | |
2051 | <citerefentry> | |
c464fd7e SG |
2052 | <refentrytitle><command>chroot</command></refentrytitle> |
2053 | <manvolnum>1</manvolnum> | |
55fc19a1 SG |
2054 | </citerefentry>, |
2055 | ||
2056 | <citerefentry> | |
c464fd7e SG |
2057 | <refentrytitle><command>pivot_root</command></refentrytitle> |
2058 | <manvolnum>8</manvolnum> | |
55fc19a1 SG |
2059 | </citerefentry>, |
2060 | ||
2061 | <citerefentry> | |
c464fd7e SG |
2062 | <refentrytitle><filename>fstab</filename></refentrytitle> |
2063 | <manvolnum>5</manvolnum> | |
55fc19a1 SG |
2064 | </citerefentry>, |
2065 | ||
2066 | <citerefentry> | |
c464fd7e SG |
2067 | <refentrytitle><filename>capabilities</filename></refentrytitle> |
2068 | <manvolnum>7</manvolnum> | |
55fc19a1 SG |
2069 | </citerefentry> |
2070 | </simpara> | |
2071 | </refsect1> | |
2072 | ||
2073 | &seealso; | |
2074 | ||
2075 | <refsect1> | |
2076 | <title>Author</title> | |
2077 | <para>Daniel Lezcano <email>daniel.lezcano@free.fr</email></para> | |
2078 | </refsect1> | |
2079 | ||
2080 | </refentry> | |
2081 | ||
2082 | <!-- Keep this comment at the end of the file | |
2083 | Local variables: | |
2084 | mode: sgml | |
2085 | sgml-omittag:t | |
2086 | sgml-shorttag:t | |
2087 | sgml-minimize-attributes:nil | |
2088 | sgml-always-quote-attributes:t | |
2089 | sgml-indent-step:2 | |
2090 | sgml-indent-data:t | |
2091 | sgml-parent-document:nil | |
2092 | sgml-default-dtd-file:nil | |
2093 | sgml-exposed-tags:nil | |
2094 | sgml-local-catalogs:nil | |
2095 | sgml-local-ecat-files:nil | |
2096 | End: | |
2097 | --> |