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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> | |
52 | The linux containers (<command>lxc</command>) are always created | |
53 | before being used. This creation defines a set of system | |
54 | resources to be virtualized / isolated when a process is using | |
55 | the container. By default, the pids, sysv ipc and mount points | |
56 | are virtualized and isolated. The other system resources are | |
57 | shared across containers, until they are explicitly defined in | |
58 | the configuration file. For example, if there is no network | |
59 | configuration, the network will be shared between the creator of | |
60 | the container and the container itself, but if the network is | |
61 | specified, a new network stack is created for the container and | |
62 | the container can no longer use the network of its ancestor. | |
63 | </para> | |
64 | ||
65 | <para> | |
66 | The configuration file defines the different system resources to | |
67 | be assigned for the container. At present, the utsname, the | |
68 | network, the mount points, the root file system, the user namespace, | |
69 | and the control groups are supported. | |
70 | </para> | |
71 | ||
72 | <para> | |
73 | Each option in the configuration file has the form <command>key | |
74 | = value</command> fitting in one line. The '#' character means | |
75 | the line is a comment. | |
76 | </para> | |
77 | ||
78 | <refsect2> | |
79 | <title>Configuration</title> | |
80 | <para> | |
c464fd7e SG |
81 | In order to ease administration of multiple related containers, it |
82 | is possible to have a container configuration file cause another | |
83 | file to be loaded. For instance, network configuration | |
84 | can be defined in one common file which is included by multiple | |
85 | containers. Then, if the containers are moved to another host, | |
86 | only one file may need to be updated. | |
55fc19a1 SG |
87 | </para> |
88 | ||
89 | <variablelist> | |
c464fd7e SG |
90 | <varlistentry> |
91 | <term> | |
92 | <option>lxc.include</option> | |
93 | </term> | |
94 | <listitem> | |
95 | <para> | |
96 | Specify the file to be included. The included file must be | |
97 | in the same valid lxc configuration file format. | |
98 | </para> | |
99 | </listitem> | |
100 | </varlistentry> | |
55fc19a1 SG |
101 | </variablelist> |
102 | </refsect2> | |
103 | ||
104 | <refsect2> | |
105 | <title>Architecture</title> | |
106 | <para> | |
c464fd7e SG |
107 | Allows one to set the architecture for the container. For example, |
108 | set a 32bits architecture for a container running 32bits | |
109 | binaries on a 64bits host. This fixes the container scripts | |
110 | which rely on the architecture to do some work like | |
111 | downloading the packages. | |
55fc19a1 SG |
112 | </para> |
113 | ||
114 | <variablelist> | |
c464fd7e SG |
115 | <varlistentry> |
116 | <term> | |
117 | <option>lxc.arch</option> | |
118 | </term> | |
119 | <listitem> | |
120 | <para> | |
121 | Specify the architecture for the container. | |
122 | </para> | |
123 | <para> | |
124 | Valid options are | |
125 | <option>x86</option>, | |
126 | <option>i686</option>, | |
127 | <option>x86_64</option>, | |
128 | <option>amd64</option> | |
129 | </para> | |
130 | </listitem> | |
131 | </varlistentry> | |
55fc19a1 SG |
132 | </variablelist> |
133 | ||
134 | </refsect2> | |
135 | ||
136 | <refsect2> | |
137 | <title>Hostname</title> | |
138 | <para> | |
c464fd7e SG |
139 | The utsname section defines the hostname to be set for the |
140 | container. That means the container can set its own hostname | |
141 | without changing the one from the system. That makes the | |
142 | hostname private for the container. | |
55fc19a1 SG |
143 | </para> |
144 | <variablelist> | |
c464fd7e SG |
145 | <varlistentry> |
146 | <term> | |
147 | <option>lxc.utsname</option> | |
148 | </term> | |
149 | <listitem> | |
150 | <para> | |
151 | specify the hostname for the container | |
152 | </para> | |
153 | </listitem> | |
154 | </varlistentry> | |
55fc19a1 SG |
155 | </variablelist> |
156 | </refsect2> | |
157 | ||
158 | <refsect2> | |
159 | <title>Halt signal</title> | |
160 | <para> | |
936762f3 BP |
161 | Allows one to specify signal name or number, sent by lxc-stop to the |
162 | container's init process to cleanly shutdown the container. Different | |
163 | init systems could use different signals to perform clean shutdown | |
164 | sequence. This option allows the signal to be specified in kill(1) | |
165 | fashion, e.g. SIGPWR, SIGRTMIN+14, SIGRTMAX-10 or plain number. The | |
166 | default signal is SIGPWR. | |
55fc19a1 SG |
167 | </para> |
168 | <variablelist> | |
936762f3 BP |
169 | <varlistentry> |
170 | <term> | |
171 | <option>lxc.haltsignal</option> | |
172 | </term> | |
173 | <listitem> | |
174 | <para> | |
175 | specify the signal used to halt the container | |
176 | </para> | |
177 | </listitem> | |
178 | </varlistentry> | |
179 | </variablelist> | |
180 | </refsect2> | |
181 | ||
182 | <refsect2> | |
183 | <title>Reboot signal</title> | |
184 | <para> | |
185 | Allows one to specify signal name or number, sent by lxc-stop to | |
186 | reboot the container. This option allows signal to be specified in | |
187 | kill(1) fashion, e.g. SIGTERM, SIGRTMIN+14, SIGRTMAX-10 or plain number. | |
188 | The default signal is SIGINT. | |
189 | </para> | |
190 | <variablelist> | |
191 | <varlistentry> | |
192 | <term> | |
193 | <option>lxc.rebootsignal</option> | |
194 | </term> | |
195 | <listitem> | |
196 | <para> | |
197 | specify the signal used to reboot the container | |
198 | </para> | |
199 | </listitem> | |
200 | </varlistentry> | |
55fc19a1 SG |
201 | </variablelist> |
202 | </refsect2> | |
203 | ||
204 | <refsect2> | |
205 | <title>Stop signal</title> | |
206 | <para> | |
936762f3 BP |
207 | Allows one to specify signal name or number, sent by lxc-stop to forcibly |
208 | shutdown the container. This option allows signal to be specified in | |
209 | kill(1) fashion, e.g. SIGKILL, SIGRTMIN+14, SIGRTMAX-10 or plain number. | |
210 | The default signal is SIGKILL. | |
211 | </para> | |
212 | <variablelist> | |
213 | <varlistentry> | |
214 | <term> | |
215 | <option>lxc.stopsignal</option> | |
216 | </term> | |
217 | <listitem> | |
218 | <para> | |
219 | specify the signal used to stop the container | |
220 | </para> | |
221 | </listitem> | |
222 | </varlistentry> | |
55fc19a1 SG |
223 | </variablelist> |
224 | </refsect2> | |
225 | ||
67c660d0 SG |
226 | <refsect2> |
227 | <title>Init command</title> | |
228 | <para> | |
229 | Sets the command to use as the init system for the containers. | |
230 | ||
231 | This option is ignored when using lxc-execute. | |
232 | ||
233 | Defaults to: /sbin/init | |
234 | </para> | |
235 | <variablelist> | |
936762f3 BP |
236 | <varlistentry> |
237 | <term> | |
238 | <option>lxc.init_cmd</option> | |
239 | </term> | |
240 | <listitem> | |
241 | <para> | |
242 | Absolute path from container rootfs to the binary to use as init. | |
243 | </para> | |
244 | </listitem> | |
245 | </varlistentry> | |
67c660d0 SG |
246 | </variablelist> |
247 | </refsect2> | |
248 | ||
55fc19a1 SG |
249 | <refsect2> |
250 | <title>Network</title> | |
251 | <para> | |
c464fd7e SG |
252 | The network section defines how the network is virtualized in |
253 | the container. The network virtualization acts at layer | |
254 | two. In order to use the network virtualization, parameters | |
255 | must be specified to define the network interfaces of the | |
256 | container. Several virtual interfaces can be assigned and used | |
257 | in a container even if the system has only one physical | |
258 | network interface. | |
55fc19a1 SG |
259 | </para> |
260 | <variablelist> | |
c464fd7e SG |
261 | <varlistentry> |
262 | <term> | |
263 | <option>lxc.network.type</option> | |
264 | </term> | |
265 | <listitem> | |
266 | <para> | |
267 | specify what kind of network virtualization to be used | |
268 | for the container. Each time | |
269 | a <option>lxc.network.type</option> field is found a new | |
270 | round of network configuration begins. In this way, | |
271 | several network virtualization types can be specified | |
272 | for the same container, as well as assigning several | |
273 | network interfaces for one container. The different | |
274 | virtualization types can be: | |
275 | </para> | |
276 | ||
277 | <para> | |
278 | <option>none:</option> will cause the container to share | |
279 | the host's network namespace. This means the host | |
280 | network devices are usable in the container. It also | |
281 | means that if both the container and host have upstart as | |
282 | init, 'halt' in a container (for instance) will shut down the | |
283 | host. | |
284 | </para> | |
285 | ||
286 | <para> | |
287 | <option>empty:</option> will create only the loopback | |
288 | interface. | |
289 | </para> | |
290 | ||
291 | <para> | |
38005c54 MA |
292 | <option>veth:</option> a virtual ethernet pair |
293 | device is created with one side assigned to the container | |
294 | and the other side attached to a bridge specified by | |
295 | the <option>lxc.network.link</option> option. | |
296 | If the bridge is not specified, then the veth pair device | |
297 | will be created but not attached to any bridge. | |
298 | Otherwise, the bridge has to be created on the system | |
299 | before starting the container. | |
300 | <command>lxc</command> won't handle any | |
301 | configuration outside of the container. | |
302 | By default, <command>lxc</command> chooses a name for the | |
c464fd7e | 303 | network device belonging to the outside of the |
38005c54 MA |
304 | container, but if you wish to handle |
305 | this name yourselves, you can tell <command>lxc</command> | |
c464fd7e SG |
306 | to set a specific name with |
307 | the <option>lxc.network.veth.pair</option> option (except for | |
308 | unprivileged containers where this option is ignored for security | |
309 | reasons). | |
310 | </para> | |
311 | ||
312 | <para> | |
313 | <option>vlan:</option> a vlan interface is linked with | |
314 | the interface specified by | |
315 | the <option>lxc.network.link</option> and assigned to | |
316 | the container. The vlan identifier is specified with the | |
317 | option <option>lxc.network.vlan.id</option>. | |
318 | </para> | |
319 | ||
320 | <para> | |
321 | <option>macvlan:</option> a macvlan interface is linked | |
322 | with the interface specified by | |
323 | the <option>lxc.network.link</option> and assigned to | |
324 | the container. | |
325 | <option>lxc.network.macvlan.mode</option> specifies the | |
326 | mode the macvlan will use to communicate between | |
327 | different macvlan on the same upper device. The accepted | |
328 | modes are <option>private</option>, the device never | |
329 | communicates with any other device on the same upper_dev (default), | |
330 | <option>vepa</option>, the new Virtual Ethernet Port | |
331 | Aggregator (VEPA) mode, it assumes that the adjacent | |
332 | bridge returns all frames where both source and | |
333 | destination are local to the macvlan port, i.e. the | |
334 | bridge is set up as a reflective relay. Broadcast | |
335 | frames coming in from the upper_dev get flooded to all | |
336 | macvlan interfaces in VEPA mode, local frames are not | |
337 | delivered locally, or <option>bridge</option>, it | |
338 | provides the behavior of a simple bridge between | |
339 | different macvlan interfaces on the same port. Frames | |
340 | from one interface to another one get delivered directly | |
341 | and are not sent out externally. Broadcast frames get | |
342 | flooded to all other bridge ports and to the external | |
343 | interface, but when they come back from a reflective | |
344 | relay, we don't deliver them again. Since we know all | |
345 | the MAC addresses, the macvlan bridge mode does not | |
346 | require learning or STP like the bridge module does. | |
347 | </para> | |
348 | ||
349 | <para> | |
350 | <option>phys:</option> an already existing interface | |
351 | specified by the <option>lxc.network.link</option> is | |
352 | assigned to the container. | |
353 | </para> | |
354 | </listitem> | |
355 | </varlistentry> | |
356 | ||
357 | <varlistentry> | |
358 | <term> | |
359 | <option>lxc.network.flags</option> | |
360 | </term> | |
361 | <listitem> | |
362 | <para> | |
363 | specify an action to do for the | |
364 | network. | |
365 | </para> | |
366 | ||
367 | <para><option>up:</option> activates the interface. | |
368 | </para> | |
369 | </listitem> | |
370 | </varlistentry> | |
371 | ||
372 | <varlistentry> | |
373 | <term> | |
374 | <option>lxc.network.link</option> | |
375 | </term> | |
376 | <listitem> | |
377 | <para> | |
378 | specify the interface to be used for real network | |
379 | traffic. | |
380 | </para> | |
381 | </listitem> | |
382 | </varlistentry> | |
383 | ||
384 | <varlistentry> | |
385 | <term> | |
386 | <option>lxc.network.mtu</option> | |
387 | </term> | |
388 | <listitem> | |
389 | <para> | |
390 | specify the maximum transfer unit for this interface. | |
391 | </para> | |
392 | </listitem> | |
393 | </varlistentry> | |
394 | ||
395 | <varlistentry> | |
396 | <term> | |
397 | <option>lxc.network.name</option> | |
398 | </term> | |
399 | <listitem> | |
400 | <para> | |
401 | the interface name is dynamically allocated, but if | |
402 | another name is needed because the configuration files | |
403 | being used by the container use a generic name, | |
404 | eg. eth0, this option will rename the interface in the | |
405 | container. | |
406 | </para> | |
407 | </listitem> | |
408 | </varlistentry> | |
409 | ||
410 | <varlistentry> | |
411 | <term> | |
412 | <option>lxc.network.hwaddr</option> | |
413 | </term> | |
414 | <listitem> | |
415 | <para> | |
416 | the interface mac address is dynamically allocated by | |
417 | default to the virtual interface, but in some cases, | |
418 | this is needed to resolve a mac address conflict or to | |
419 | always have the same link-local ipv6 address. | |
420 | Any "x" in address will be replaced by random value, | |
421 | this allows setting hwaddr templates. | |
422 | </para> | |
423 | </listitem> | |
424 | </varlistentry> | |
425 | ||
426 | <varlistentry> | |
427 | <term> | |
428 | <option>lxc.network.ipv4</option> | |
429 | </term> | |
430 | <listitem> | |
431 | <para> | |
432 | specify the ipv4 address to assign to the virtualized | |
433 | interface. Several lines specify several ipv4 addresses. | |
434 | The address is in format x.y.z.t/m, | |
435 | eg. 192.168.1.123/24. The broadcast address should be | |
436 | specified on the same line, right after the ipv4 | |
437 | address. | |
438 | </para> | |
439 | </listitem> | |
440 | </varlistentry> | |
441 | ||
442 | <varlistentry> | |
443 | <term> | |
444 | <option>lxc.network.ipv4.gateway</option> | |
445 | </term> | |
446 | <listitem> | |
447 | <para> | |
448 | specify the ipv4 address to use as the gateway inside the | |
449 | container. The address is in format x.y.z.t, eg. | |
450 | 192.168.1.123. | |
451 | ||
452 | Can also have the special value <option>auto</option>, | |
453 | which means to take the primary address from the bridge | |
454 | interface (as specified by the | |
455 | <option>lxc.network.link</option> option) and use that as | |
456 | the gateway. <option>auto</option> is only available when | |
457 | using the <option>veth</option> and | |
458 | <option>macvlan</option> network types. | |
459 | </para> | |
460 | </listitem> | |
461 | </varlistentry> | |
462 | ||
463 | ||
464 | <varlistentry> | |
465 | <term> | |
466 | <option>lxc.network.ipv6</option> | |
467 | </term> | |
468 | <listitem> | |
469 | <para> | |
470 | specify the ipv6 address to assign to the virtualized | |
471 | interface. Several lines specify several ipv6 addresses. | |
472 | The address is in format x::y/m, | |
473 | eg. 2003:db8:1:0:214:1234:fe0b:3596/64 | |
474 | </para> | |
475 | </listitem> | |
476 | </varlistentry> | |
477 | ||
478 | <varlistentry> | |
479 | <term> | |
480 | <option>lxc.network.ipv6.gateway</option> | |
481 | </term> | |
482 | <listitem> | |
483 | <para> | |
484 | specify the ipv6 address to use as the gateway inside the | |
485 | container. The address is in format x::y, | |
486 | eg. 2003:db8:1:0::1 | |
487 | ||
488 | Can also have the special value <option>auto</option>, | |
489 | which means to take the primary address from the bridge | |
490 | interface (as specified by the | |
491 | <option>lxc.network.link</option> option) and use that as | |
492 | the gateway. <option>auto</option> is only available when | |
493 | using the <option>veth</option> and | |
494 | <option>macvlan</option> network types. | |
495 | </para> | |
496 | </listitem> | |
497 | </varlistentry> | |
498 | ||
499 | <varlistentry> | |
500 | <term> | |
501 | <option>lxc.network.script.up</option> | |
502 | </term> | |
503 | <listitem> | |
504 | <para> | |
505 | add a configuration option to specify a script to be | |
506 | executed after creating and configuring the network used | |
507 | from the host side. The following arguments are passed | |
508 | to the script: container name and config section name | |
509 | (net) Additional arguments depend on the config section | |
510 | employing a script hook; the following are used by the | |
511 | network system: execution context (up), network type | |
512 | (empty/veth/macvlan/phys), Depending on the network | |
513 | type, other arguments may be passed: | |
514 | veth/macvlan/phys. And finally (host-sided) device name. | |
515 | </para> | |
516 | <para> | |
517 | Standard output from the script is logged at debug level. | |
518 | Standard error is not logged, but can be captured by the | |
519 | hook redirecting its standard error to standard output. | |
520 | </para> | |
521 | </listitem> | |
522 | </varlistentry> | |
523 | ||
524 | <varlistentry> | |
525 | <term> | |
526 | <option>lxc.network.script.down</option> | |
527 | </term> | |
528 | <listitem> | |
529 | <para> | |
530 | add a configuration option to specify a script to be | |
531 | executed before destroying the network used from the | |
532 | host side. The following arguments are passed to the | |
533 | script: container name and config section name (net) | |
534 | Additional arguments depend on the config section | |
535 | employing a script hook; the following are used by the | |
536 | network system: execution context (down), network type | |
537 | (empty/veth/macvlan/phys), Depending on the network | |
538 | type, other arguments may be passed: | |
539 | veth/macvlan/phys. And finally (host-sided) device name. | |
540 | </para> | |
541 | <para> | |
542 | Standard output from the script is logged at debug level. | |
543 | Standard error is not logged, but can be captured by the | |
544 | hook redirecting its standard error to standard output. | |
545 | </para> | |
546 | </listitem> | |
547 | </varlistentry> | |
55fc19a1 SG |
548 | </variablelist> |
549 | </refsect2> | |
550 | ||
551 | <refsect2> | |
552 | <title>New pseudo tty instance (devpts)</title> | |
553 | <para> | |
c464fd7e SG |
554 | For stricter isolation the container can have its own private |
555 | instance of the pseudo tty. | |
55fc19a1 SG |
556 | </para> |
557 | <variablelist> | |
c464fd7e SG |
558 | <varlistentry> |
559 | <term> | |
560 | <option>lxc.pts</option> | |
561 | </term> | |
562 | <listitem> | |
563 | <para> | |
564 | If set, the container will have a new pseudo tty | |
565 | instance, making this private to it. The value specifies | |
55fc19a1 SG |
566 | the maximum number of pseudo ttys allowed for a pts |
567 | instance (this limitation is not implemented yet). | |
c464fd7e SG |
568 | </para> |
569 | </listitem> | |
570 | </varlistentry> | |
55fc19a1 SG |
571 | </variablelist> |
572 | </refsect2> | |
573 | ||
574 | <refsect2> | |
575 | <title>Container system console</title> | |
576 | <para> | |
c464fd7e SG |
577 | If the container is configured with a root filesystem and the |
578 | inittab file is setup to use the console, you may want to specify | |
579 | where the output of this console goes. | |
55fc19a1 SG |
580 | </para> |
581 | <variablelist> | |
c464fd7e SG |
582 | <varlistentry> |
583 | <term> | |
584 | <option>lxc.console.logfile</option> | |
585 | </term> | |
586 | <listitem> | |
587 | <para> | |
588 | Specify a path to a file where the console output will | |
589 | be written. | |
590 | </para> | |
591 | </listitem> | |
592 | </varlistentry> | |
593 | <varlistentry> | |
594 | <term> | |
595 | <option>lxc.console</option> | |
596 | </term> | |
597 | <listitem> | |
598 | <para> | |
599 | Specify a path to a device to which the console will be | |
600 | attached. The keyword 'none' will simply disable the | |
601 | console. This is dangerous once if have a rootfs with a | |
602 | console device file where the application can write, the | |
603 | messages will fall in the host. | |
604 | </para> | |
605 | </listitem> | |
606 | </varlistentry> | |
55fc19a1 SG |
607 | </variablelist> |
608 | </refsect2> | |
609 | ||
610 | <refsect2> | |
611 | <title>Console through the ttys</title> | |
612 | <para> | |
c464fd7e SG |
613 | This option is useful if the container is configured with a root |
614 | filesystem and the inittab file is setup to launch a getty on the | |
615 | ttys. The option specifies the number of ttys to be available for | |
616 | the container. The number of gettys in the inittab file of the | |
617 | container should not be greater than the number of ttys specified | |
618 | in this option, otherwise the excess getty sessions will die and | |
619 | respawn indefinitely giving annoying messages on the console or in | |
620 | <filename>/var/log/messages</filename>. | |
55fc19a1 SG |
621 | </para> |
622 | <variablelist> | |
c464fd7e SG |
623 | <varlistentry> |
624 | <term> | |
625 | <option>lxc.tty</option> | |
626 | </term> | |
627 | <listitem> | |
628 | <para> | |
629 | Specify the number of tty to make available to the | |
630 | container. | |
631 | </para> | |
632 | </listitem> | |
633 | </varlistentry> | |
55fc19a1 SG |
634 | </variablelist> |
635 | </refsect2> | |
636 | ||
637 | <refsect2> | |
638 | <title>Console devices location</title> | |
639 | <para> | |
640 | LXC consoles are provided through Unix98 PTYs created on the | |
c464fd7e SG |
641 | host and bind-mounted over the expected devices in the container. |
642 | By default, they are bind-mounted over <filename>/dev/console</filename> | |
643 | and <filename>/dev/ttyN</filename>. This can prevent package upgrades | |
644 | in the guest. Therefore you can specify a directory location (under | |
645 | <filename>/dev</filename> under which LXC will create the files and | |
646 | bind-mount over them. These will then be symbolically linked to | |
647 | <filename>/dev/console</filename> and <filename>/dev/ttyN</filename>. | |
648 | A package upgrade can then succeed as it is able to remove and replace | |
649 | the symbolic links. | |
55fc19a1 SG |
650 | </para> |
651 | <variablelist> | |
c464fd7e SG |
652 | <varlistentry> |
653 | <term> | |
654 | <option>lxc.devttydir</option> | |
655 | </term> | |
656 | <listitem> | |
657 | <para> | |
658 | Specify a directory under <filename>/dev</filename> | |
659 | under which to create the container console devices. | |
660 | </para> | |
661 | </listitem> | |
662 | </varlistentry> | |
55fc19a1 SG |
663 | </variablelist> |
664 | </refsect2> | |
665 | ||
666 | <refsect2> | |
667 | <title>/dev directory</title> | |
668 | <para> | |
c464fd7e SG |
669 | By default, lxc creates a few symbolic links (fd,stdin,stdout,stderr) |
670 | in the container's <filename>/dev</filename> directory but does not | |
671 | automatically create device node entries. This allows the container's | |
672 | <filename>/dev</filename> to be set up as needed in the container | |
673 | rootfs. If lxc.autodev is set to 1, then after mounting the container's | |
674 | rootfs LXC will mount a fresh tmpfs under <filename>/dev</filename> | |
675 | (limited to 100k) and fill in a minimal set of initial devices. | |
55fc19a1 SG |
676 | This is generally required when starting a container containing |
677 | a "systemd" based "init" but may be optional at other times. Additional | |
678 | devices in the containers /dev directory may be created through the | |
679 | use of the <option>lxc.hook.autodev</option> hook. | |
680 | </para> | |
681 | <variablelist> | |
c464fd7e SG |
682 | <varlistentry> |
683 | <term> | |
684 | <option>lxc.autodev</option> | |
685 | </term> | |
686 | <listitem> | |
687 | <para> | |
124fa0a8 | 688 | Set this to 0 to stop LXC from mounting and populating a minimal |
c464fd7e SG |
689 | <filename>/dev</filename> when starting the container. |
690 | </para> | |
691 | </listitem> | |
692 | </varlistentry> | |
55fc19a1 SG |
693 | </variablelist> |
694 | </refsect2> | |
695 | ||
696 | <refsect2> | |
697 | <title>Enable kmsg symlink</title> | |
698 | <para> | |
d89de239 | 699 | Enable creating /dev/kmsg as symlink to /dev/console. This defaults to 0. |
55fc19a1 SG |
700 | </para> |
701 | <variablelist> | |
702 | <varlistentry> | |
703 | <term> | |
704 | <option>lxc.kmsg</option> | |
705 | </term> | |
706 | <listitem> | |
707 | <para> | |
d89de239 | 708 | Set this to 1 to enable /dev/kmsg symlinking. |
55fc19a1 SG |
709 | </para> |
710 | </listitem> | |
711 | </varlistentry> | |
712 | </variablelist> | |
713 | </refsect2> | |
714 | ||
715 | <refsect2> | |
716 | <title>Mount points</title> | |
717 | <para> | |
c464fd7e SG |
718 | The mount points section specifies the different places to be |
719 | mounted. These mount points will be private to the container | |
720 | and won't be visible by the processes running outside of the | |
721 | container. This is useful to mount /etc, /var or /home for | |
722 | examples. | |
55fc19a1 SG |
723 | </para> |
724 | <variablelist> | |
c464fd7e SG |
725 | <varlistentry> |
726 | <term> | |
727 | <option>lxc.mount</option> | |
728 | </term> | |
729 | <listitem> | |
730 | <para> | |
731 | specify a file location in | |
732 | the <filename>fstab</filename> format, containing the | |
733 | mount information. The mount target location can and in | |
734 | most cases should be a relative path, which will become | |
735 | relative to the mounted container root. For instance, | |
736 | </para> | |
6191f4f4 SH |
737 | <screen> |
738 | proc proc proc nodev,noexec,nosuid 0 0 | |
739 | </screen> | |
c464fd7e SG |
740 | <para> |
741 | Will mount a proc filesystem under the container's /proc, | |
742 | regardless of where the root filesystem comes from. This | |
743 | is resilient to block device backed filesystems as well as | |
744 | container cloning. | |
745 | </para> | |
746 | <para> | |
747 | Note that when mounting a filesystem from an | |
748 | image file or block device the third field (fs_vfstype) | |
749 | cannot be auto as with | |
55fc19a1 | 750 | <citerefentry> |
c464fd7e | 751 | <refentrytitle>mount</refentrytitle> |
55fc19a1 SG |
752 | <manvolnum>8</manvolnum> |
753 | </citerefentry> | |
754 | but must be explicitly specified. | |
c464fd7e SG |
755 | </para> |
756 | </listitem> | |
757 | </varlistentry> | |
758 | ||
759 | <varlistentry> | |
760 | <term> | |
761 | <option>lxc.mount.entry</option> | |
762 | </term> | |
763 | <listitem> | |
764 | <para> | |
765 | specify a mount point corresponding to a line in the | |
766 | fstab format. | |
767 | </para> | |
768 | </listitem> | |
769 | </varlistentry> | |
770 | ||
771 | <varlistentry> | |
772 | <term> | |
773 | <option>lxc.mount.auto</option> | |
774 | </term> | |
775 | <listitem> | |
776 | <para> | |
777 | specify which standard kernel file systems should be | |
778 | automatically mounted. This may dramatically simplify | |
779 | the configuration. The file systems are: | |
780 | </para> | |
781 | <itemizedlist> | |
782 | <listitem> | |
783 | <para> | |
784 | <option>proc:mixed</option> (or <option>proc</option>): | |
785 | mount <filename>/proc</filename> as read-write, but | |
786 | remount <filename>/proc/sys</filename> and | |
787 | <filename>/proc/sysrq-trigger</filename> read-only | |
788 | for security / container isolation purposes. | |
789 | </para> | |
790 | </listitem> | |
791 | <listitem> | |
792 | <para> | |
793 | <option>proc:rw</option>: mount | |
794 | <filename>/proc</filename> as read-write | |
795 | </para> | |
796 | </listitem> | |
797 | <listitem> | |
798 | <para> | |
f24a52d5 SG |
799 | <option>sys:mixed</option> (or <option>sys</option>): |
800 | mount <filename>/sys</filename> as read-only but with | |
801 | /sys/devices/virtual/net writable. | |
802 | </para> | |
803 | </listitem> | |
804 | <listitem> | |
805 | <para> | |
806 | <option>sys:ro</option>: | |
c464fd7e SG |
807 | mount <filename>/sys</filename> as read-only |
808 | for security / container isolation purposes. | |
809 | </para> | |
810 | </listitem> | |
811 | <listitem> | |
812 | <para> | |
813 | <option>sys:rw</option>: mount | |
814 | <filename>/sys</filename> as read-write | |
815 | </para> | |
816 | </listitem> | |
817 | <listitem> | |
818 | <para> | |
819 | <option>cgroup:mixed</option>: | |
820 | mount a tmpfs to <filename>/sys/fs/cgroup</filename>, | |
821 | create directories for all hierarchies to which | |
822 | the container is added, create subdirectories | |
823 | there with the name of the cgroup, and bind-mount | |
824 | the container's own cgroup into that directory. | |
825 | The container will be able to write to its own | |
826 | cgroup directory, but not the parents, since they | |
827 | will be remounted read-only | |
828 | </para> | |
829 | </listitem> | |
830 | <listitem> | |
831 | <para> | |
832 | <option>cgroup:ro</option>: similar to | |
833 | <option>cgroup:mixed</option>, but everything will | |
834 | be mounted read-only. | |
835 | </para> | |
836 | </listitem> | |
837 | <listitem> | |
838 | <para> | |
839 | <option>cgroup:rw</option>: similar to | |
840 | <option>cgroup:mixed</option>, but everything will | |
841 | be mounted read-write. Note that the paths leading | |
842 | up to the container's own cgroup will be writable, | |
843 | but will not be a cgroup filesystem but just part | |
844 | of the tmpfs of <filename>/sys/fs/cgroup</filename> | |
845 | </para> | |
846 | </listitem> | |
847 | <listitem> | |
848 | <para> | |
849 | <option>cgroup</option> (without specifier): | |
850 | defaults to <option>cgroup:rw</option> if the | |
851 | container retains the CAP_SYS_ADMIN capability, | |
852 | <option>cgroup:mixed</option> otherwise. | |
853 | </para> | |
854 | </listitem> | |
855 | <listitem> | |
856 | <para> | |
857 | <option>cgroup-full:mixed</option>: | |
858 | mount a tmpfs to <filename>/sys/fs/cgroup</filename>, | |
859 | create directories for all hierarchies to which | |
860 | the container is added, bind-mount the hierarchies | |
861 | from the host to the container and make everything | |
862 | read-only except the container's own cgroup. Note | |
863 | that compared to <option>cgroup</option>, where | |
864 | all paths leading up to the container's own cgroup | |
865 | are just simple directories in the underlying | |
866 | tmpfs, here | |
867 | <filename>/sys/fs/cgroup/$hierarchy</filename> | |
868 | will contain the host's full cgroup hierarchy, | |
869 | albeit read-only outside the container's own cgroup. | |
870 | This may leak quite a bit of information into the | |
871 | container. | |
872 | </para> | |
873 | </listitem> | |
874 | <listitem> | |
875 | <para> | |
876 | <option>cgroup-full:ro</option>: similar to | |
877 | <option>cgroup-full:mixed</option>, but everything | |
878 | will be mounted read-only. | |
879 | </para> | |
880 | </listitem> | |
881 | <listitem> | |
882 | <para> | |
883 | <option>cgroup-full:rw</option>: similar to | |
884 | <option>cgroup-full:mixed</option>, but everything | |
885 | will be mounted read-write. Note that in this case, | |
886 | the container may escape its own cgroup. (Note also | |
887 | that if the container has CAP_SYS_ADMIN support | |
888 | and can mount the cgroup filesystem itself, it may | |
889 | do so anyway.) | |
890 | </para> | |
891 | </listitem> | |
892 | <listitem> | |
893 | <para> | |
894 | <option>cgroup-full</option> (without specifier): | |
895 | defaults to <option>cgroup-full:rw</option> if the | |
896 | container retains the CAP_SYS_ADMIN capability, | |
897 | <option>cgroup-full:mixed</option> otherwise. | |
898 | </para> | |
899 | </listitem> | |
900 | </itemizedlist> | |
901 | <para> | |
902 | Note that if automatic mounting of the cgroup filesystem | |
903 | is enabled, the tmpfs under | |
904 | <filename>/sys/fs/cgroup</filename> will always be | |
905 | mounted read-write (but for the <option>:mixed</option> | |
906 | and <option>:ro</option> cases, the individual | |
907 | hierarchies, | |
908 | <filename>/sys/fs/cgroup/$hierarchy</filename>, will be | |
909 | read-only). This is in order to work around a quirk in | |
910 | Ubuntu's | |
b46f0553 | 911 | <citerefentry> |
c464fd7e | 912 | <refentrytitle>mountall</refentrytitle> |
b46f0553 CS |
913 | <manvolnum>8</manvolnum> |
914 | </citerefentry> | |
c464fd7e SG |
915 | command that will cause containers to wait for user |
916 | input at boot if | |
917 | <filename>/sys/fs/cgroup</filename> is mounted read-only | |
918 | and the container can't remount it read-write due to a | |
919 | lack of CAP_SYS_ADMIN. | |
920 | </para> | |
921 | <para> | |
922 | Examples: | |
923 | </para> | |
924 | <programlisting> | |
925 | lxc.mount.auto = proc sys cgroup | |
926 | lxc.mount.auto = proc:rw sys:rw cgroup-full:rw | |
927 | </programlisting> | |
928 | </listitem> | |
929 | </varlistentry> | |
55fc19a1 SG |
930 | |
931 | </variablelist> | |
932 | </refsect2> | |
933 | ||
934 | <refsect2> | |
935 | <title>Root file system</title> | |
936 | <para> | |
c464fd7e SG |
937 | The root file system of the container can be different than that |
938 | of the host system. | |
55fc19a1 SG |
939 | </para> |
940 | <variablelist> | |
c464fd7e SG |
941 | <varlistentry> |
942 | <term> | |
943 | <option>lxc.rootfs</option> | |
944 | </term> | |
945 | <listitem> | |
946 | <para> | |
947 | specify the root file system for the container. It can | |
948 | be an image file, a directory or a block device. If not | |
949 | specified, the container shares its root file system | |
950 | with the host. | |
951 | </para> | |
952 | <para> | |
f1c26f2c SH |
953 | For directory or simple block-device backed containers, |
954 | a pathname can be used. If the rootfs is backed by a nbd | |
955 | device, then <filename>nbd:file:1</filename> specifies that | |
956 | <filename>file</filename> should be attached to a nbd device, | |
957 | and partition 1 should be mounted as the rootfs. | |
958 | <filename>nbd:file</filename> specifies that the nbd device | |
959 | itself should be mounted. <filename>overlayfs:/lower:/upper</filename> | |
960 | specifies that the rootfs should be an overlay with <filename>/upper</filename> | |
961 | being mounted read-write over a read-only mount of <filename>/lower</filename>. | |
962 | <filename>aufs:/lower:/upper</filename> does the same using aufs in place | |
963 | of overlayfs. <filename>loop:/file</filename> tells lxc to attach | |
964 | <filename>/file</filename> to a loop device and mount the loop device. | |
c464fd7e SG |
965 | </para> |
966 | </listitem> | |
967 | </varlistentry> | |
968 | ||
969 | <varlistentry> | |
970 | <term> | |
971 | <option>lxc.rootfs.mount</option> | |
972 | </term> | |
973 | <listitem> | |
974 | <para> | |
975 | where to recursively bind <option>lxc.rootfs</option> | |
976 | before pivoting. This is to ensure success of the | |
977 | <citerefentry> | |
978 | <refentrytitle><command>pivot_root</command></refentrytitle> | |
979 | <manvolnum>8</manvolnum> | |
980 | </citerefentry> | |
981 | syscall. Any directory suffices, the default should | |
982 | generally work. | |
983 | </para> | |
984 | </listitem> | |
985 | </varlistentry> | |
986 | ||
987 | <varlistentry> | |
988 | <term> | |
989 | <option>lxc.rootfs.options</option> | |
990 | </term> | |
991 | <listitem> | |
992 | <para> | |
993 | extra mount options to use when mounting the rootfs. | |
994 | </para> | |
995 | </listitem> | |
996 | </varlistentry> | |
a17b1e65 | 997 | |
55fc19a1 SG |
998 | </variablelist> |
999 | </refsect2> | |
1000 | ||
1001 | <refsect2> | |
1002 | <title>Control group</title> | |
1003 | <para> | |
c464fd7e SG |
1004 | The control group section contains the configuration for the |
1005 | different subsystem. <command>lxc</command> does not check the | |
1006 | correctness of the subsystem name. This has the disadvantage | |
1007 | of not detecting configuration errors until the container is | |
1008 | started, but has the advantage of permitting any future | |
1009 | subsystem. | |
55fc19a1 SG |
1010 | </para> |
1011 | <variablelist> | |
c464fd7e SG |
1012 | <varlistentry> |
1013 | <term> | |
1014 | <option>lxc.cgroup.[subsystem name]</option> | |
1015 | </term> | |
1016 | <listitem> | |
1017 | <para> | |
1018 | specify the control group value to be set. The | |
1019 | subsystem name is the literal name of the control group | |
1020 | subsystem. The permitted names and the syntax of their | |
1021 | values is not dictated by LXC, instead it depends on the | |
1022 | features of the Linux kernel running at the time the | |
1023 | container is started, | |
1024 | eg. <option>lxc.cgroup.cpuset.cpus</option> | |
1025 | </para> | |
1026 | </listitem> | |
1027 | </varlistentry> | |
55fc19a1 SG |
1028 | </variablelist> |
1029 | </refsect2> | |
1030 | ||
1031 | <refsect2> | |
1032 | <title>Capabilities</title> | |
1033 | <para> | |
c464fd7e SG |
1034 | The capabilities can be dropped in the container if this one |
1035 | is run as root. | |
55fc19a1 SG |
1036 | </para> |
1037 | <variablelist> | |
c464fd7e SG |
1038 | <varlistentry> |
1039 | <term> | |
1040 | <option>lxc.cap.drop</option> | |
1041 | </term> | |
1042 | <listitem> | |
1043 | <para> | |
1044 | Specify the capability to be dropped in the container. A | |
1045 | single line defining several capabilities with a space | |
1046 | separation is allowed. The format is the lower case of | |
1047 | the capability definition without the "CAP_" prefix, | |
1048 | eg. CAP_SYS_MODULE should be specified as | |
1049 | sys_module. See | |
1050 | <citerefentry> | |
1051 | <refentrytitle><command>capabilities</command></refentrytitle> | |
1052 | <manvolnum>7</manvolnum> | |
1053 | </citerefentry>, | |
1054 | </para> | |
1055 | </listitem> | |
1056 | </varlistentry> | |
1057 | <varlistentry> | |
1058 | <term> | |
1059 | <option>lxc.cap.keep</option> | |
1060 | </term> | |
1061 | <listitem> | |
1062 | <para> | |
1063 | Specify the capability to be kept in the container. All other | |
1064 | capabilities will be dropped. When a special value of "none" is | |
1065 | encountered, lxc will clear any keep capabilities specified up | |
1066 | to this point. A value of "none" alone can be used to drop all | |
1067 | capabilities. | |
1068 | </para> | |
1069 | </listitem> | |
1070 | </varlistentry> | |
55fc19a1 SG |
1071 | </variablelist> |
1072 | </refsect2> | |
1073 | ||
1074 | <refsect2> | |
1075 | <title>Apparmor profile</title> | |
1076 | <para> | |
c464fd7e SG |
1077 | If lxc was compiled and installed with apparmor support, and the host |
1078 | system has apparmor enabled, then the apparmor profile under which the | |
1079 | container should be run can be specified in the container | |
1080 | configuration. The default is <command>lxc-container-default</command>. | |
55fc19a1 SG |
1081 | </para> |
1082 | <variablelist> | |
c464fd7e SG |
1083 | <varlistentry> |
1084 | <term> | |
1085 | <option>lxc.aa_profile</option> | |
1086 | </term> | |
1087 | <listitem> | |
1088 | <para> | |
1089 | Specify the apparmor profile under which the container should | |
1090 | be run. To specify that the container should be unconfined, | |
1091 | use | |
1092 | </para> | |
1093 | <programlisting>lxc.aa_profile = unconfined</programlisting> | |
1094 | </listitem> | |
1095 | </varlistentry> | |
1096 | <varlistentry> | |
1097 | <term> | |
1098 | <option>lxc.aa_allow_incomplete</option> | |
1099 | </term> | |
1100 | <listitem> | |
1101 | <para> | |
1102 | Apparmor profiles are pathname based. Therefore many file | |
1103 | restrictions require mount restrictions to be effective against | |
1104 | a determined attacker. However, these mount restrictions are not | |
1105 | yet implemented in the upstream kernel. Without the mount | |
1106 | restrictions, the apparmor profiles still protect against accidental | |
1107 | damager. | |
1108 | </para> | |
1109 | <para> | |
1110 | If this flag is 0 (default), then the container will not be | |
1111 | started if the kernel lacks the apparmor mount features, so that a | |
1112 | regression after a kernel upgrade will be detected. To start the | |
1113 | container under partial apparmor protection, set this flag to 1. | |
1114 | </para> | |
1115 | </listitem> | |
1116 | </varlistentry> | |
55fc19a1 SG |
1117 | </variablelist> |
1118 | </refsect2> | |
1119 | ||
1120 | <refsect2> | |
1121 | <title>SELinux context</title> | |
1122 | <para> | |
c464fd7e SG |
1123 | If lxc was compiled and installed with SELinux support, and the host |
1124 | system has SELinux enabled, then the SELinux context under which the | |
1125 | container should be run can be specified in the container | |
1126 | configuration. The default is <command>unconfined_t</command>, | |
1127 | which means that lxc will not attempt to change contexts. | |
1128 | See @DATADIR@/lxc/selinux/lxc.te for an example policy and more | |
1129 | information. | |
55fc19a1 SG |
1130 | </para> |
1131 | <variablelist> | |
c464fd7e SG |
1132 | <varlistentry> |
1133 | <term> | |
1134 | <option>lxc.se_context</option> | |
1135 | </term> | |
1136 | <listitem> | |
1137 | <para> | |
1138 | Specify the SELinux context under which the container should | |
1139 | be run or <command>unconfined_t</command>. For example | |
1140 | </para> | |
1141 | <programlisting>lxc.se_context = system_u:system_r:lxc_t:s0:c22</programlisting> | |
1142 | </listitem> | |
1143 | </varlistentry> | |
55fc19a1 SG |
1144 | </variablelist> |
1145 | </refsect2> | |
1146 | ||
1147 | <refsect2> | |
1148 | <title>Seccomp configuration</title> | |
1149 | <para> | |
1150 | A container can be started with a reduced set of available | |
c464fd7e SG |
1151 | system calls by loading a seccomp profile at startup. The |
1152 | seccomp configuration file must begin with a version number | |
1153 | on the first line, a policy type on the second line, followed | |
1154 | by the configuration. | |
55fc19a1 | 1155 | </para> |
a7c27357 SH |
1156 | <para> |
1157 | Versions 1 and 2 are currently supported. In version 1, the | |
c464fd7e SG |
1158 | policy is a simple whitelist. The second line therefore must |
1159 | read "whitelist", with the rest of the file containing one (numeric) | |
1160 | sycall number per line. Each syscall number is whitelisted, | |
1161 | while every unlisted number is blacklisted for use in the container | |
a7c27357 SH |
1162 | </para> |
1163 | ||
1164 | <para> | |
1165 | In version 2, the policy may be blacklist or whitelist, | |
1166 | supports per-rule and per-policy default actions, and supports | |
1167 | per-architecture system call resolution from textual names. | |
1168 | </para> | |
1169 | <para> | |
1170 | An example blacklist policy, in which all system calls are | |
1171 | allowed except for mknod, which will simply do nothing and | |
1172 | return 0 (success), looks like: | |
1173 | </para> | |
1174 | <screen> | |
1175 | 2 | |
1176 | blacklist | |
1177 | mknod errno 0 | |
1178 | </screen> | |
55fc19a1 | 1179 | <variablelist> |
c464fd7e SG |
1180 | <varlistentry> |
1181 | <term> | |
1182 | <option>lxc.seccomp</option> | |
1183 | </term> | |
1184 | <listitem> | |
1185 | <para> | |
1186 | Specify a file containing the seccomp configuration to | |
1187 | load before the container starts. | |
1188 | </para> | |
1189 | </listitem> | |
1190 | </varlistentry> | |
55fc19a1 SG |
1191 | </variablelist> |
1192 | </refsect2> | |
1193 | ||
1194 | <refsect2> | |
1195 | <title>UID mappings</title> | |
1196 | <para> | |
1197 | A container can be started in a private user namespace with | |
c464fd7e SG |
1198 | user and group id mappings. For instance, you can map userid |
1199 | 0 in the container to userid 200000 on the host. The root | |
1200 | user in the container will be privileged in the container, | |
1201 | but unprivileged on the host. Normally a system container | |
1202 | will want a range of ids, so you would map, for instance, | |
1203 | user and group ids 0 through 20,000 in the container to the | |
1204 | ids 200,000 through 220,000. | |
55fc19a1 SG |
1205 | </para> |
1206 | <variablelist> | |
c464fd7e SG |
1207 | <varlistentry> |
1208 | <term> | |
1209 | <option>lxc.id_map</option> | |
1210 | </term> | |
1211 | <listitem> | |
1212 | <para> | |
1213 | Four values must be provided. First a character, either | |
1214 | 'u', or 'g', to specify whether user or group ids are | |
1215 | being mapped. Next is the first userid as seen in the | |
1216 | user namespace of the container. Next is the userid as | |
1217 | seen on the host. Finally, a range indicating the number | |
1218 | of consecutive ids to map. | |
1219 | </para> | |
1220 | </listitem> | |
1221 | </varlistentry> | |
55fc19a1 SG |
1222 | </variablelist> |
1223 | </refsect2> | |
1224 | ||
1225 | <refsect2> | |
1226 | <title>Container hooks</title> | |
1227 | <para> | |
1228 | Container hooks are programs or scripts which can be executed | |
c464fd7e | 1229 | at various times in a container's lifetime. |
55fc19a1 SG |
1230 | </para> |
1231 | <para> | |
1232 | When a container hook is executed, information is passed both | |
c464fd7e SG |
1233 | as command line arguments and through environment variables. |
1234 | The arguments are: | |
1235 | <itemizedlist> | |
1236 | <listitem><para> Container name. </para></listitem> | |
1237 | <listitem><para> Section (always 'lxc'). </para></listitem> | |
1238 | <listitem><para> The hook type (i.e. 'clone' or 'pre-mount'). </para></listitem> | |
1239 | <listitem><para> Additional arguments In the | |
1240 | case of the clone hook, any extra arguments passed to | |
1241 | lxc-clone will appear as further arguments to the hook. </para></listitem> | |
1242 | </itemizedlist> | |
1243 | The following environment variables are set: | |
1244 | <itemizedlist> | |
1245 | <listitem><para> LXC_NAME: is the container's name. </para></listitem> | |
1246 | <listitem><para> LXC_ROOTFS_MOUNT: the path to the mounted root filesystem. </para></listitem> | |
1247 | <listitem><para> LXC_CONFIG_FILE: the path to the container configuration file. </para></listitem> | |
1248 | <listitem><para> LXC_SRC_NAME: in the case of the clone hook, this is the original container's name. </para></listitem> | |
1249 | <listitem><para> LXC_ROOTFS_PATH: this is the lxc.rootfs 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> | |
1250 | </itemizedlist> | |
55fc19a1 SG |
1251 | </para> |
1252 | <para> | |
1253 | Standard output from the hooks is logged at debug level. | |
1254 | Standard error is not logged, but can be captured by the | |
1255 | hook redirecting its standard error to standard output. | |
1256 | </para> | |
1257 | <variablelist> | |
c464fd7e SG |
1258 | <varlistentry> |
1259 | <term> | |
1260 | <option>lxc.hook.pre-start</option> | |
1261 | </term> | |
1262 | <listitem> | |
1263 | <para> | |
1264 | A hook to be run in the host's namespace before the | |
1265 | container ttys, consoles, or mounts are up. | |
1266 | </para> | |
1267 | </listitem> | |
1268 | </varlistentry> | |
55fc19a1 SG |
1269 | </variablelist> |
1270 | <variablelist> | |
c464fd7e SG |
1271 | <varlistentry> |
1272 | <term> | |
1273 | <option>lxc.hook.pre-mount</option> | |
1274 | </term> | |
1275 | <listitem> | |
1276 | <para> | |
1277 | A hook to be run in the container's fs namespace but before | |
1278 | the rootfs has been set up. This allows for manipulation | |
1279 | of the rootfs, i.e. to mount an encrypted filesystem. Mounts | |
1280 | done in this hook will not be reflected on the host (apart from | |
1281 | mounts propagation), so they will be automatically cleaned up | |
1282 | when the container shuts down. | |
1283 | </para> | |
1284 | </listitem> | |
1285 | </varlistentry> | |
55fc19a1 SG |
1286 | </variablelist> |
1287 | <variablelist> | |
c464fd7e SG |
1288 | <varlistentry> |
1289 | <term> | |
1290 | <option>lxc.hook.mount</option> | |
1291 | </term> | |
1292 | <listitem> | |
1293 | <para> | |
1294 | A hook to be run in the container's namespace after | |
1295 | mounting has been done, but before the pivot_root. | |
1296 | </para> | |
1297 | </listitem> | |
1298 | </varlistentry> | |
55fc19a1 SG |
1299 | </variablelist> |
1300 | <variablelist> | |
c464fd7e SG |
1301 | <varlistentry> |
1302 | <term> | |
1303 | <option>lxc.hook.autodev</option> | |
1304 | </term> | |
1305 | <listitem> | |
1306 | <para> | |
1307 | A hook to be run in the container's namespace after | |
1308 | mounting has been done and after any mount hooks have | |
1309 | run, but before the pivot_root, if | |
1310 | <option>lxc.autodev</option> == 1. | |
1311 | The purpose of this hook is to assist in populating the | |
1312 | /dev directory of the container when using the autodev | |
1313 | option for systemd based containers. The container's /dev | |
1314 | directory is relative to the | |
1315 | ${<option>LXC_ROOTFS_MOUNT</option>} environment | |
1316 | variable available when the hook is run. | |
1317 | </para> | |
1318 | </listitem> | |
1319 | </varlistentry> | |
55fc19a1 SG |
1320 | </variablelist> |
1321 | <variablelist> | |
c464fd7e SG |
1322 | <varlistentry> |
1323 | <term> | |
1324 | <option>lxc.hook.start</option> | |
1325 | </term> | |
1326 | <listitem> | |
1327 | <para> | |
1328 | A hook to be run in the container's namespace immediately | |
1329 | before executing the container's init. This requires the | |
1330 | program to be available in the container. | |
1331 | </para> | |
1332 | </listitem> | |
1333 | </varlistentry> | |
55fc19a1 SG |
1334 | </variablelist> |
1335 | <variablelist> | |
c464fd7e SG |
1336 | <varlistentry> |
1337 | <term> | |
1338 | <option>lxc.hook.post-stop</option> | |
1339 | </term> | |
1340 | <listitem> | |
1341 | <para> | |
1342 | A hook to be run in the host's namespace after the | |
1343 | container has been shut down. | |
1344 | </para> | |
1345 | </listitem> | |
1346 | </varlistentry> | |
55fc19a1 SG |
1347 | </variablelist> |
1348 | <variablelist> | |
c464fd7e SG |
1349 | <varlistentry> |
1350 | <term> | |
1351 | <option>lxc.hook.clone</option> | |
1352 | </term> | |
1353 | <listitem> | |
1354 | <para> | |
1355 | A hook to be run when the container is cloned to a new one. | |
1356 | See <citerefentry><refentrytitle><command>lxc-clone</command></refentrytitle> | |
1357 | <manvolnum>1</manvolnum></citerefentry> for more information. | |
1358 | </para> | |
1359 | </listitem> | |
1360 | </varlistentry> | |
55fc19a1 SG |
1361 | </variablelist> |
1362 | </refsect2> | |
1363 | ||
1364 | <refsect2> | |
1365 | <title>Container hooks Environment Variables</title> | |
1366 | <para> | |
1367 | A number of environment variables are made available to the startup | |
1368 | hooks to provide configuration information and assist in the | |
1369 | functioning of the hooks. Not all variables are valid in all | |
1370 | contexts. In particular, all paths are relative to the host system | |
1371 | and, as such, not valid during the <option>lxc.hook.start</option> hook. | |
1372 | </para> | |
1373 | <variablelist> | |
c464fd7e SG |
1374 | <varlistentry> |
1375 | <term> | |
1376 | <option>LXC_NAME</option> | |
1377 | </term> | |
1378 | <listitem> | |
1379 | <para> | |
1380 | The LXC name of the container. Useful for logging messages | |
1381 | in common log environments. [<option>-n</option>] | |
1382 | </para> | |
1383 | </listitem> | |
1384 | </varlistentry> | |
55fc19a1 SG |
1385 | </variablelist> |
1386 | <variablelist> | |
c464fd7e SG |
1387 | <varlistentry> |
1388 | <term> | |
1389 | <option>LXC_CONFIG_FILE</option> | |
1390 | </term> | |
1391 | <listitem> | |
1392 | <para> | |
1393 | Host relative path to the container configuration file. This | |
1394 | gives the container to reference the original, top level, | |
1395 | configuration file for the container in order to locate any | |
1396 | additional configuration information not otherwise made | |
1397 | available. [<option>-f</option>] | |
1398 | </para> | |
1399 | </listitem> | |
1400 | </varlistentry> | |
55fc19a1 SG |
1401 | </variablelist> |
1402 | <variablelist> | |
c464fd7e SG |
1403 | <varlistentry> |
1404 | <term> | |
1405 | <option>LXC_CONSOLE</option> | |
1406 | </term> | |
1407 | <listitem> | |
1408 | <para> | |
1409 | The path to the console output of the container if not NULL. | |
1410 | [<option>-c</option>] [<option>lxc.console</option>] | |
1411 | </para> | |
1412 | </listitem> | |
1413 | </varlistentry> | |
55fc19a1 SG |
1414 | </variablelist> |
1415 | <variablelist> | |
c464fd7e SG |
1416 | <varlistentry> |
1417 | <term> | |
1418 | <option>LXC_CONSOLE_LOGPATH</option> | |
1419 | </term> | |
1420 | <listitem> | |
1421 | <para> | |
1422 | The path to the console log output of the container if not NULL. | |
1423 | [<option>-L</option>] | |
1424 | </para> | |
1425 | </listitem> | |
1426 | </varlistentry> | |
55fc19a1 SG |
1427 | </variablelist> |
1428 | <variablelist> | |
c464fd7e SG |
1429 | <varlistentry> |
1430 | <term> | |
1431 | <option>LXC_ROOTFS_MOUNT</option> | |
1432 | </term> | |
1433 | <listitem> | |
1434 | <para> | |
1435 | The mount location to which the container is initially bound. | |
1436 | This will be the host relative path to the container rootfs | |
1437 | for the container instance being started and is where changes | |
1438 | should be made for that instance. | |
1439 | [<option>lxc.rootfs.mount</option>] | |
1440 | </para> | |
1441 | </listitem> | |
1442 | </varlistentry> | |
55fc19a1 SG |
1443 | </variablelist> |
1444 | <variablelist> | |
c464fd7e SG |
1445 | <varlistentry> |
1446 | <term> | |
1447 | <option>LXC_ROOTFS_PATH</option> | |
1448 | </term> | |
1449 | <listitem> | |
1450 | <para> | |
1451 | The host relative path to the container root which has been | |
1452 | mounted to the rootfs.mount location. | |
1453 | [<option>lxc.rootfs</option>] | |
1454 | </para> | |
1455 | </listitem> | |
1456 | </varlistentry> | |
55fc19a1 SG |
1457 | </variablelist> |
1458 | ||
1459 | </refsect2> | |
1460 | <refsect2> | |
1461 | <title>Logging</title> | |
1462 | <para> | |
1463 | Logging can be configured on a per-container basis. By default, | |
1464 | depending upon how the lxc package was compiled, container startup | |
1465 | is logged only at the ERROR level, and logged to a file named after | |
1466 | the container (with '.log' appended) either under the container path, | |
1467 | or under @LOGPATH@. | |
1468 | </para> | |
1469 | <para> | |
1470 | Both the default log level and the log file can be specified in the | |
1471 | container configuration file, overriding the default behavior. Note | |
1472 | that the configuration file entries can in turn be overridden by the | |
1473 | command line options to <command>lxc-start</command>. | |
1474 | </para> | |
1475 | <variablelist> | |
c464fd7e SG |
1476 | <varlistentry> |
1477 | <term> | |
1478 | <option>lxc.loglevel</option> | |
1479 | </term> | |
1480 | <listitem> | |
1481 | <para> | |
1482 | The level at which to log. The log level is an integer in | |
1483 | the range of 0..8 inclusive, where a lower number means more | |
1484 | verbose debugging. In particular 0 = trace, 1 = debug, 2 = | |
1485 | info, 3 = notice, 4 = warn, 5 = error, 6 = critical, 7 = | |
1486 | alert, and 8 = fatal. If unspecified, the level defaults | |
1487 | to 5 (error), so that only errors and above are logged. | |
1488 | </para> | |
1489 | <para> | |
1490 | Note that when a script (such as either a hook script or a | |
1491 | network interface up or down script) is called, the script's | |
1492 | standard output is logged at level 1, debug. | |
1493 | </para> | |
1494 | </listitem> | |
1495 | </varlistentry> | |
1496 | <varlistentry> | |
1497 | <term> | |
1498 | <option>lxc.logfile</option> | |
1499 | </term> | |
1500 | <listitem> | |
1501 | <para> | |
1502 | The file to which logging info should be written. | |
1503 | </para> | |
1504 | </listitem> | |
1505 | </varlistentry> | |
55fc19a1 SG |
1506 | </variablelist> |
1507 | </refsect2> | |
1508 | ||
1509 | <refsect2> | |
1510 | <title>Autostart</title> | |
1511 | <para> | |
1512 | The autostart options support marking which containers should be | |
1513 | auto-started and in what order. These options may be used by LXC tools | |
1514 | directly or by external tooling provided by the distributions. | |
1515 | </para> | |
1516 | ||
1517 | <variablelist> | |
1518 | <varlistentry> | |
1519 | <term> | |
1520 | <option>lxc.start.auto</option> | |
1521 | </term> | |
1522 | <listitem> | |
1523 | <para> | |
1524 | Whether the container should be auto-started. | |
1525 | Valid values are 0 (off) and 1 (on). | |
1526 | </para> | |
1527 | </listitem> | |
1528 | </varlistentry> | |
1529 | <varlistentry> | |
1530 | <term> | |
1531 | <option>lxc.start.delay</option> | |
1532 | </term> | |
1533 | <listitem> | |
1534 | <para> | |
1535 | How long to wait (in seconds) after the container is | |
1536 | started before starting the next one. | |
1537 | </para> | |
1538 | </listitem> | |
1539 | </varlistentry> | |
1540 | <varlistentry> | |
1541 | <term> | |
1542 | <option>lxc.start.order</option> | |
1543 | </term> | |
1544 | <listitem> | |
1545 | <para> | |
1546 | An integer used to sort the containers when auto-starting | |
1547 | a series of containers at once. | |
1548 | </para> | |
1549 | </listitem> | |
1550 | </varlistentry> | |
1551 | <varlistentry> | |
1552 | <term> | |
1553 | <option>lxc.group</option> | |
1554 | </term> | |
1555 | <listitem> | |
1556 | <para> | |
1557 | A multi-value key (can be used multiple times) to put the | |
1558 | container in a container group. Those groups can then be | |
1559 | used (amongst other things) to start a series of related | |
1560 | containers. | |
1561 | </para> | |
1562 | </listitem> | |
1563 | </varlistentry> | |
1564 | </variablelist> | |
1565 | </refsect2> | |
015f0dd7 MW |
1566 | |
1567 | <refsect2> | |
1568 | <title>Autostart and System Boot</title> | |
1569 | <para> | |
1570 | Each container can be part of any number of groups or no group at all. | |
1571 | Two groups are special. One is the NULL group, i.e. the container does | |
1572 | not belong to any group. The other group is the "onboot" group. | |
1573 | </para> | |
1574 | ||
1575 | <para> | |
1576 | When the system boots with the LXC service enabled, it will first | |
1577 | attempt to boot any containers with lxc.start.auto == 1 that is a member | |
1578 | of the "onboot" group. The startup will be in order of lxc.start.order. | |
1579 | If an lxc.start.delay has been specified, that delay will be honored | |
1580 | before attempting to start the next container to give the current | |
1581 | container time to begin initialization and reduce overloading the host | |
1582 | system. After starting the members of the "onboot" group, the LXC system | |
1583 | will proceed to boot containers with lxc.start.auto == 1 which are not | |
1584 | members of any group (the NULL group) and proceed as with the onboot | |
1585 | group. | |
1586 | </para> | |
1587 | ||
1588 | </refsect2> | |
7c661726 MP |
1589 | |
1590 | <refsect2> | |
1591 | <title>Container Environment</title> | |
1592 | <para> | |
c464fd7e SG |
1593 | If you want to pass environment variables into the container (that |
1594 | is, environment variables which will be available to init and all of | |
1595 | its descendents), you can use <command>lxc.environment</command> | |
1596 | parameters to do so. Be careful that you do not pass in anything | |
1597 | sensitive; any process in the container which doesn't have its | |
1598 | environment scrubbed will have these variables available to it, and | |
1599 | environment variables are always available via | |
1600 | <command>/proc/PID/environ</command>. | |
7c661726 MP |
1601 | </para> |
1602 | ||
1603 | <para> | |
1604 | This configuration parameter can be specified multiple times; once | |
1605 | for each environment variable you wish to configure. | |
1606 | </para> | |
1607 | ||
1608 | <variablelist> | |
c464fd7e SG |
1609 | <varlistentry> |
1610 | <term> | |
1611 | <option>lxc.environment</option> | |
1612 | </term> | |
1613 | <listitem> | |
1614 | <para> | |
1615 | Specify an environment variable to pass into the container. | |
1616 | Example: | |
1617 | </para> | |
1618 | <programlisting> | |
1619 | lxc.environment = APP_ENV=production | |
1620 | lxc.environment = SYSLOG_SERVER=192.0.2.42 | |
1621 | </programlisting> | |
1622 | </listitem> | |
1623 | </varlistentry> | |
7c661726 MP |
1624 | </variablelist> |
1625 | </refsect2> | |
1626 | ||
55fc19a1 SG |
1627 | </refsect1> |
1628 | ||
1629 | <refsect1> | |
1630 | <title>Examples</title> | |
1631 | <para> | |
c464fd7e SG |
1632 | In addition to the few examples given below, you will find |
1633 | some other examples of configuration file in @DOCDIR@/examples | |
55fc19a1 SG |
1634 | </para> |
1635 | <refsect2> | |
1636 | <title>Network</title> | |
1637 | <para>This configuration sets up a container to use a veth pair | |
c464fd7e SG |
1638 | device with one side plugged to a bridge br0 (which has been |
1639 | configured before on the system by the administrator). The | |
1640 | virtual network device visible in the container is renamed to | |
1641 | eth0.</para> | |
55fc19a1 | 1642 | <programlisting> |
c464fd7e SG |
1643 | lxc.utsname = myhostname |
1644 | lxc.network.type = veth | |
1645 | lxc.network.flags = up | |
1646 | lxc.network.link = br0 | |
1647 | lxc.network.name = eth0 | |
1648 | lxc.network.hwaddr = 4a:49:43:49:79:bf | |
1649 | lxc.network.ipv4 = 10.2.3.5/24 10.2.3.255 | |
1650 | lxc.network.ipv6 = 2003:db8:1:0:214:1234:fe0b:3597 | |
55fc19a1 SG |
1651 | </programlisting> |
1652 | </refsect2> | |
1653 | ||
1654 | <refsect2> | |
1655 | <title>UID/GID mapping</title> | |
1656 | <para>This configuration will map both user and group ids in the | |
1657 | range 0-9999 in the container to the ids 100000-109999 on the host. | |
1658 | </para> | |
1659 | <programlisting> | |
c464fd7e SG |
1660 | lxc.id_map = u 0 100000 10000 |
1661 | lxc.id_map = g 0 100000 10000 | |
55fc19a1 SG |
1662 | </programlisting> |
1663 | </refsect2> | |
1664 | ||
1665 | <refsect2> | |
1666 | <title>Control group</title> | |
1667 | <para>This configuration will setup several control groups for | |
1668 | the application, cpuset.cpus restricts usage of the defined cpu, | |
1669 | cpus.share prioritize the control group, devices.allow makes | |
1670 | usable the specified devices.</para> | |
1671 | <programlisting> | |
c464fd7e SG |
1672 | lxc.cgroup.cpuset.cpus = 0,1 |
1673 | lxc.cgroup.cpu.shares = 1234 | |
1674 | lxc.cgroup.devices.deny = a | |
1675 | lxc.cgroup.devices.allow = c 1:3 rw | |
1676 | lxc.cgroup.devices.allow = b 8:0 rw | |
55fc19a1 SG |
1677 | </programlisting> |
1678 | </refsect2> | |
1679 | ||
1680 | <refsect2> | |
1681 | <title>Complex configuration</title> | |
1682 | <para>This example show a complex configuration making a complex | |
1683 | network stack, using the control groups, setting a new hostname, | |
1684 | mounting some locations and a changing root file system.</para> | |
1685 | <programlisting> | |
c464fd7e SG |
1686 | lxc.utsname = complex |
1687 | lxc.network.type = veth | |
1688 | lxc.network.flags = up | |
1689 | lxc.network.link = br0 | |
1690 | lxc.network.hwaddr = 4a:49:43:49:79:bf | |
1691 | lxc.network.ipv4 = 10.2.3.5/24 10.2.3.255 | |
1692 | lxc.network.ipv6 = 2003:db8:1:0:214:1234:fe0b:3597 | |
1693 | lxc.network.ipv6 = 2003:db8:1:0:214:5432:feab:3588 | |
1694 | lxc.network.type = macvlan | |
1695 | lxc.network.flags = up | |
1696 | lxc.network.link = eth0 | |
1697 | lxc.network.hwaddr = 4a:49:43:49:79:bd | |
1698 | lxc.network.ipv4 = 10.2.3.4/24 | |
1699 | lxc.network.ipv4 = 192.168.10.125/24 | |
1700 | lxc.network.ipv6 = 2003:db8:1:0:214:1234:fe0b:3596 | |
1701 | lxc.network.type = phys | |
1702 | lxc.network.flags = up | |
1703 | lxc.network.link = dummy0 | |
1704 | lxc.network.hwaddr = 4a:49:43:49:79:ff | |
1705 | lxc.network.ipv4 = 10.2.3.6/24 | |
1706 | lxc.network.ipv6 = 2003:db8:1:0:214:1234:fe0b:3297 | |
1707 | lxc.cgroup.cpuset.cpus = 0,1 | |
1708 | lxc.cgroup.cpu.shares = 1234 | |
1709 | lxc.cgroup.devices.deny = a | |
1710 | lxc.cgroup.devices.allow = c 1:3 rw | |
1711 | lxc.cgroup.devices.allow = b 8:0 rw | |
1712 | lxc.mount = /etc/fstab.complex | |
1713 | lxc.mount.entry = /lib /root/myrootfs/lib none ro,bind 0 0 | |
1714 | lxc.rootfs = /mnt/rootfs.complex | |
1715 | lxc.cap.drop = sys_module mknod setuid net_raw | |
1716 | lxc.cap.drop = mac_override | |
55fc19a1 SG |
1717 | </programlisting> |
1718 | </refsect2> | |
1719 | ||
1720 | </refsect1> | |
1721 | ||
1722 | <refsect1> | |
1723 | <title>See Also</title> | |
1724 | <simpara> | |
1725 | <citerefentry> | |
c464fd7e SG |
1726 | <refentrytitle><command>chroot</command></refentrytitle> |
1727 | <manvolnum>1</manvolnum> | |
55fc19a1 SG |
1728 | </citerefentry>, |
1729 | ||
1730 | <citerefentry> | |
c464fd7e SG |
1731 | <refentrytitle><command>pivot_root</command></refentrytitle> |
1732 | <manvolnum>8</manvolnum> | |
55fc19a1 SG |
1733 | </citerefentry>, |
1734 | ||
1735 | <citerefentry> | |
c464fd7e SG |
1736 | <refentrytitle><filename>fstab</filename></refentrytitle> |
1737 | <manvolnum>5</manvolnum> | |
55fc19a1 SG |
1738 | </citerefentry>, |
1739 | ||
1740 | <citerefentry> | |
c464fd7e SG |
1741 | <refentrytitle><filename>capabilities</filename></refentrytitle> |
1742 | <manvolnum>7</manvolnum> | |
55fc19a1 SG |
1743 | </citerefentry> |
1744 | </simpara> | |
1745 | </refsect1> | |
1746 | ||
1747 | &seealso; | |
1748 | ||
1749 | <refsect1> | |
1750 | <title>Author</title> | |
1751 | <para>Daniel Lezcano <email>daniel.lezcano@free.fr</email></para> | |
1752 | </refsect1> | |
1753 | ||
1754 | </refentry> | |
1755 | ||
1756 | <!-- Keep this comment at the end of the file | |
1757 | Local variables: | |
1758 | mode: sgml | |
1759 | sgml-omittag:t | |
1760 | sgml-shorttag:t | |
1761 | sgml-minimize-attributes:nil | |
1762 | sgml-always-quote-attributes:t | |
1763 | sgml-indent-step:2 | |
1764 | sgml-indent-data:t | |
1765 | sgml-parent-document:nil | |
1766 | sgml-default-dtd-file:nil | |
1767 | sgml-exposed-tags:nil | |
1768 | sgml-local-catalogs:nil | |
1769 | sgml-local-ecat-files:nil | |
1770 | End: | |
1771 | --> |