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1 | [[chapter_pct]] | |
2 | ifdef::manvolnum[] | |
3 | pct(1) | |
4 | ====== | |
5 | :pve-toplevel: | |
6 | ||
7 | NAME | |
8 | ---- | |
9 | ||
10 | pct - Tool to manage Linux Containers (LXC) on Proxmox VE | |
11 | ||
12 | ||
13 | SYNOPSIS | |
14 | -------- | |
15 | ||
16 | include::pct.1-synopsis.adoc[] | |
17 | ||
18 | DESCRIPTION | |
19 | ----------- | |
20 | endif::manvolnum[] | |
21 | ||
22 | ifndef::manvolnum[] | |
23 | Proxmox Container Toolkit | |
24 | ========================= | |
25 | :pve-toplevel: | |
26 | endif::manvolnum[] | |
27 | ifdef::wiki[] | |
28 | :title: Linux Container | |
29 | endif::wiki[] | |
30 | ||
31 | Containers are a lightweight alternative to fully virtualized machines (VMs). | |
32 | They use the kernel of the host system that they run on, instead of emulating a | |
33 | full operating system (OS). This means that containers can access resources on | |
34 | the host system directly. | |
35 | ||
36 | The runtime costs for containers is low, usually negligible. However, there are | |
37 | some drawbacks that need be considered: | |
38 | ||
39 | * Only Linux distributions can be run in containers.It is not possible to run | |
40 | other Operating Systems like, for example, FreeBSD or Microsoft Windows | |
41 | inside a container. | |
42 | ||
43 | * For security reasons, access to host resources needs to be restricted. | |
44 | Containers run in their own separate namespaces. Additionally some syscalls | |
45 | are not allowed within containers. | |
46 | ||
47 | {pve} uses https://linuxcontainers.org/[Linux Containers (LXC)] as underlying | |
48 | container technology. The ``Proxmox Container Toolkit'' (`pct`) simplifies the | |
49 | usage and management of LXC containers. | |
50 | ||
51 | Containers are tightly integrated with {pve}. This means that they are aware of | |
52 | the cluster setup, and they can use the same network and storage resources as | |
53 | virtual machines. You can also use the {pve} firewall, or manage containers | |
54 | using the HA framework. | |
55 | ||
56 | Our primary goal is to offer an environment as one would get from a VM, but | |
57 | without the additional overhead. We call this ``System Containers''. | |
58 | ||
59 | NOTE: If you want to run micro-containers, for example, 'Docker' or 'rkt', it | |
60 | is best to run them inside a VM. | |
61 | ||
62 | ||
63 | Technology Overview | |
64 | ------------------- | |
65 | ||
66 | * LXC (https://linuxcontainers.org/) | |
67 | ||
68 | * Integrated into {pve} graphical web user interface (GUI) | |
69 | ||
70 | * Easy to use command line tool `pct` | |
71 | ||
72 | * Access via {pve} REST API | |
73 | ||
74 | * 'lxcfs' to provide containerized /proc file system | |
75 | ||
76 | * Control groups ('cgroups') for resource isolation and limitation | |
77 | ||
78 | * 'AppArmor' and 'seccomp' to improve security | |
79 | ||
80 | * Modern Linux kernels | |
81 | ||
82 | * Image based deployment (templates) | |
83 | ||
84 | * Uses {pve} xref:chapter_storage[storage library] | |
85 | ||
86 | * Container setup from host (network, DNS, storage, etc.) | |
87 | ||
88 | ||
89 | Security Considerations | |
90 | ----------------------- | |
91 | ||
92 | Containers use the kernel of the host system. This creates a big attack surface | |
93 | for malicious users. This should be considered if containers are provided to | |
94 | untrustworthy people. In general, full virtual machines provide better | |
95 | isolation. | |
96 | ||
97 | However, LXC uses many security features like AppArmor, CGroups and kernel | |
98 | namespaces to reduce the attack surface. | |
99 | ||
100 | AppArmor profiles are used to restrict access to possibly dangerous actions. | |
101 | Some system calls, i.e. `mount`, are prohibited from execution. | |
102 | ||
103 | To trace AppArmor activity, use: | |
104 | ||
105 | ---- | |
106 | # dmesg | grep apparmor | |
107 | ---- | |
108 | ||
109 | Guest Operating System Configuration | |
110 | ------------------------------------ | |
111 | ||
112 | {pve} tries to detect the Linux distribution in the container, and modifies | |
113 | some files. Here is a short list of things done at container startup: | |
114 | ||
115 | set /etc/hostname:: to set the container name | |
116 | ||
117 | modify /etc/hosts:: to allow lookup of the local hostname | |
118 | ||
119 | network setup:: pass the complete network setup to the container | |
120 | ||
121 | configure DNS:: pass information about DNS servers | |
122 | ||
123 | adapt the init system:: for example, fix the number of spawned getty processes | |
124 | ||
125 | set the root password:: when creating a new container | |
126 | ||
127 | rewrite ssh_host_keys:: so that each container has unique keys | |
128 | ||
129 | randomize crontab:: so that cron does not start at the same time on all containers | |
130 | ||
131 | Changes made by {PVE} are enclosed by comment markers: | |
132 | ||
133 | ---- | |
134 | # --- BEGIN PVE --- | |
135 | <data> | |
136 | # --- END PVE --- | |
137 | ---- | |
138 | ||
139 | Those markers will be inserted at a reasonable location in the file. If such a | |
140 | section already exists, it will be updated in place and will not be moved. | |
141 | ||
142 | Modification of a file can be prevented by adding a `.pve-ignore.` file for it. | |
143 | For instance, if the file `/etc/.pve-ignore.hosts` exists then the `/etc/hosts` | |
144 | file will not be touched. This can be a simple empty file created via: | |
145 | ||
146 | ---- | |
147 | # touch /etc/.pve-ignore.hosts | |
148 | ---- | |
149 | ||
150 | Most modifications are OS dependent, so they differ between different | |
151 | distributions and versions. You can completely disable modifications by | |
152 | manually setting the `ostype` to `unmanaged`. | |
153 | ||
154 | OS type detection is done by testing for certain files inside the | |
155 | container: | |
156 | ||
157 | Ubuntu:: inspect /etc/lsb-release (`DISTRIB_ID=Ubuntu`) | |
158 | ||
159 | Debian:: test /etc/debian_version | |
160 | ||
161 | Fedora:: test /etc/fedora-release | |
162 | ||
163 | RedHat or CentOS:: test /etc/redhat-release | |
164 | ||
165 | ArchLinux:: test /etc/arch-release | |
166 | ||
167 | Alpine:: test /etc/alpine-release | |
168 | ||
169 | Gentoo:: test /etc/gentoo-release | |
170 | ||
171 | NOTE: Container start fails if the configured `ostype` differs from the auto | |
172 | detected type. | |
173 | ||
174 | ||
175 | [[pct_container_images]] | |
176 | Container Images | |
177 | ---------------- | |
178 | ||
179 | Container images, sometimes also referred to as ``templates'' or | |
180 | ``appliances'', are `tar` archives which contain everything to run a container. | |
181 | `pct` uses them to create a new container, for example: | |
182 | ||
183 | ---- | |
184 | # pct create 999 local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz | |
185 | ---- | |
186 | ||
187 | {pve} itself provides a variety of basic templates for the most common Linux | |
188 | distributions. They can be downloaded using the GUI or the `pveam` (short for | |
189 | {pve} Appliance Manager) command line utility. | |
190 | Additionally, https://www.turnkeylinux.org/[TurnKey Linux] container templates | |
191 | are also available to download. | |
192 | ||
193 | The list of available templates is updated daily via cron. To trigger it | |
194 | manually: | |
195 | ||
196 | ---- | |
197 | # pveam update | |
198 | ---- | |
199 | ||
200 | To view the list of available images run: | |
201 | ||
202 | ---- | |
203 | # pveam available | |
204 | ---- | |
205 | ||
206 | You can restrict this large list by specifying the `section` you are | |
207 | interested in, for example basic `system` images: | |
208 | ||
209 | .List available system images | |
210 | ---- | |
211 | # pveam available --section system | |
212 | system alpine-3.10-default_20190626_amd64.tar.xz | |
213 | system alpine-3.9-default_20190224_amd64.tar.xz | |
214 | system archlinux-base_20190924-1_amd64.tar.gz | |
215 | system centos-6-default_20191016_amd64.tar.xz | |
216 | system centos-7-default_20190926_amd64.tar.xz | |
217 | system centos-8-default_20191016_amd64.tar.xz | |
218 | system debian-10.0-standard_10.0-1_amd64.tar.gz | |
219 | system debian-8.0-standard_8.11-1_amd64.tar.gz | |
220 | system debian-9.0-standard_9.7-1_amd64.tar.gz | |
221 | system fedora-30-default_20190718_amd64.tar.xz | |
222 | system fedora-31-default_20191029_amd64.tar.xz | |
223 | system gentoo-current-default_20190718_amd64.tar.xz | |
224 | system opensuse-15.0-default_20180907_amd64.tar.xz | |
225 | system opensuse-15.1-default_20190719_amd64.tar.xz | |
226 | system ubuntu-16.04-standard_16.04.5-1_amd64.tar.gz | |
227 | system ubuntu-18.04-standard_18.04.1-1_amd64.tar.gz | |
228 | system ubuntu-19.04-standard_19.04-1_amd64.tar.gz | |
229 | system ubuntu-19.10-standard_19.10-1_amd64.tar.gz | |
230 | ---- | |
231 | ||
232 | Before you can use such a template, you need to download them into one of your | |
233 | storages. You can simply use storage `local` for that purpose. For clustered | |
234 | installations, it is preferred to use a shared storage so that all nodes can | |
235 | access those images. | |
236 | ||
237 | ---- | |
238 | # pveam download local debian-10.0-standard_10.0-1_amd64.tar.gz | |
239 | ---- | |
240 | ||
241 | You are now ready to create containers using that image, and you can list all | |
242 | downloaded images on storage `local` with: | |
243 | ||
244 | ---- | |
245 | # pveam list local | |
246 | local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz 219.95MB | |
247 | ---- | |
248 | ||
249 | The above command shows you the full {pve} volume identifiers. They include the | |
250 | storage name, and most other {pve} commands can use them. For example you can | |
251 | delete that image later with: | |
252 | ||
253 | ---- | |
254 | # pveam remove local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz | |
255 | ---- | |
256 | ||
257 | [[pct_container_storage]] | |
258 | Container Storage | |
259 | ----------------- | |
260 | ||
261 | The {pve} LXC container storage model is more flexible than traditional | |
262 | container storage models. A container can have multiple mount points. This | |
263 | makes it possible to use the best suited storage for each application. | |
264 | ||
265 | For example the root file system of the container can be on slow and cheap | |
266 | storage while the database can be on fast and distributed storage via a second | |
267 | mount point. See section <<pct_mount_points, Mount Points>> for further | |
268 | details. | |
269 | ||
270 | Any storage type supported by the {pve} storage library can be used. This means | |
271 | that containers can be stored on local (for example `lvm`, `zfs` or directory), | |
272 | shared external (like `iSCSI`, `NFS`) or even distributed storage systems like | |
273 | Ceph. Advanced storage features like snapshots or clones can be used if the | |
274 | underlying storage supports them. The `vzdump` backup tool can use snapshots to | |
275 | provide consistent container backups. | |
276 | ||
277 | Furthermore, local devices or local directories can be mounted directly using | |
278 | 'bind mounts'. This gives access to local resources inside a container with | |
279 | practically zero overhead. Bind mounts can be used as an easy way to share data | |
280 | between containers. | |
281 | ||
282 | ||
283 | FUSE Mounts | |
284 | ~~~~~~~~~~~ | |
285 | ||
286 | WARNING: Because of existing issues in the Linux kernel's freezer subsystem the | |
287 | usage of FUSE mounts inside a container is strongly advised against, as | |
288 | containers need to be frozen for suspend or snapshot mode backups. | |
289 | ||
290 | If FUSE mounts cannot be replaced by other mounting mechanisms or storage | |
291 | technologies, it is possible to establish the FUSE mount on the Proxmox host | |
292 | and use a bind mount point to make it accessible inside the container. | |
293 | ||
294 | ||
295 | Using Quotas Inside Containers | |
296 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
297 | ||
298 | Quotas allow to set limits inside a container for the amount of disk space that | |
299 | each user can use. | |
300 | ||
301 | NOTE: This only works on ext4 image based storage types and currently only | |
302 | works with privileged containers. | |
303 | ||
304 | Activating the `quota` option causes the following mount options to be used for | |
305 | a mount point: | |
306 | `usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0` | |
307 | ||
308 | This allows quotas to be used like on any other system. You can initialize the | |
309 | `/aquota.user` and `/aquota.group` files by running: | |
310 | ||
311 | ---- | |
312 | # quotacheck -cmug / | |
313 | # quotaon / | |
314 | ---- | |
315 | ||
316 | Then edit the quotas using the `edquota` command. Refer to the documentation of | |
317 | the distribution running inside the container for details. | |
318 | ||
319 | NOTE: You need to run the above commands for every mount point by passing the | |
320 | mount point's path instead of just `/`. | |
321 | ||
322 | ||
323 | Using ACLs Inside Containers | |
324 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
325 | ||
326 | The standard Posix **A**ccess **C**ontrol **L**ists are also available inside | |
327 | containers. ACLs allow you to set more detailed file ownership than the | |
328 | traditional user/group/others model. | |
329 | ||
330 | ||
331 | Backup of Container mount points | |
332 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
333 | ||
334 | To include a mount point in backups, enable the `backup` option for it in the | |
335 | container configuration. For an existing mount point `mp0` | |
336 | ||
337 | ---- | |
338 | mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G | |
339 | ---- | |
340 | ||
341 | add `backup=1` to enable it. | |
342 | ||
343 | ---- | |
344 | mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G,backup=1 | |
345 | ---- | |
346 | ||
347 | NOTE: When creating a new mount point in the GUI, this option is enabled by | |
348 | default. | |
349 | ||
350 | To disable backups for a mount point, add `backup=0` in the way described | |
351 | above, or uncheck the *Backup* checkbox on the GUI. | |
352 | ||
353 | Replication of Containers mount points | |
354 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
355 | ||
356 | By default, additional mount points are replicated when the Root Disk is | |
357 | replicated. If you want the {pve} storage replication mechanism to skip a mount | |
358 | point, you can set the *Skip replication* option for that mount point. | |
359 | As of {pve} 5.0, replication requires a storage of type `zfspool`. Adding a | |
360 | mount point to a different type of storage when the container has replication | |
361 | configured requires to have *Skip replication* enabled for that mount point. | |
362 | ||
363 | [[pct_settings]] | |
364 | Container Settings | |
365 | ------------------ | |
366 | ||
367 | [[pct_general]] | |
368 | General Settings | |
369 | ~~~~~~~~~~~~~~~~ | |
370 | ||
371 | [thumbnail="screenshot/gui-create-ct-general.png"] | |
372 | ||
373 | General settings of a container include | |
374 | ||
375 | * the *Node* : the physical server on which the container will run | |
376 | * the *CT ID*: a unique number in this {pve} installation used to identify your | |
377 | container | |
378 | * *Hostname*: the hostname of the container | |
379 | * *Resource Pool*: a logical group of containers and VMs | |
380 | * *Password*: the root password of the container | |
381 | * *SSH Public Key*: a public key for connecting to the root account over SSH | |
382 | * *Unprivileged container*: this option allows to choose at creation time | |
383 | if you want to create a privileged or unprivileged container. | |
384 | ||
385 | Unprivileged Containers | |
386 | ^^^^^^^^^^^^^^^^^^^^^^^ | |
387 | ||
388 | Unprivileged containers use a new kernel feature called user namespaces. | |
389 | The root UID 0 inside the container is mapped to an unprivileged user outside | |
390 | the container. This means that most security issues (container escape, resource | |
391 | abuse, etc.) in these containers will affect a random unprivileged user, and | |
392 | would be a generic kernel security bug rather than an LXC issue. The LXC team | |
393 | thinks unprivileged containers are safe by design. | |
394 | ||
395 | This is the default option when creating a new container. | |
396 | ||
397 | NOTE: If the container uses systemd as an init system, please be aware the | |
398 | systemd version running inside the container should be equal to or greater than | |
399 | 220. | |
400 | ||
401 | ||
402 | Privileged Containers | |
403 | ^^^^^^^^^^^^^^^^^^^^^ | |
404 | ||
405 | Security in containers is achieved by using mandatory access control | |
406 | ('AppArmor'), 'seccomp' filters and namespaces. The LXC team considers this | |
407 | kind of container as unsafe, and they will not consider new container escape | |
408 | exploits to be security issues worthy of a CVE and quick fix. That's why | |
409 | privileged containers should only be used in trusted environments. | |
410 | ||
411 | Although it is not recommended, AppArmor can be disabled for a container. This | |
412 | brings security risks with it. Some syscalls can lead to privilege escalation | |
413 | when executed within a container if the system is misconfigured or if a LXC or | |
414 | Linux Kernel vulnerability exists. | |
415 | ||
416 | To disable AppArmor for a container, add the following line to the container | |
417 | configuration file located at `/etc/pve/lxc/CTID.conf`: | |
418 | ||
419 | ---- | |
420 | lxc.apparmor_profile = unconfined | |
421 | ---- | |
422 | ||
423 | WARNING: Please note that this is not recommended for production use. | |
424 | ||
425 | ||
426 | [[pct_cpu]] | |
427 | CPU | |
428 | ~~~ | |
429 | ||
430 | [thumbnail="screenshot/gui-create-ct-cpu.png"] | |
431 | ||
432 | You can restrict the number of visible CPUs inside the container using the | |
433 | `cores` option. This is implemented using the Linux 'cpuset' cgroup | |
434 | (**c**ontrol *group*). | |
435 | A special task inside `pvestatd` tries to distribute running containers among | |
436 | available CPUs periodically. | |
437 | To view the assigned CPUs run the following command: | |
438 | ||
439 | ---- | |
440 | # pct cpusets | |
441 | --------------------- | |
442 | 102: 6 7 | |
443 | 105: 2 3 4 5 | |
444 | 108: 0 1 | |
445 | --------------------- | |
446 | ---- | |
447 | ||
448 | Containers use the host kernel directly. All tasks inside a container are | |
449 | handled by the host CPU scheduler. {pve} uses the Linux 'CFS' (**C**ompletely | |
450 | **F**air **S**cheduler) scheduler by default, which has additional bandwidth | |
451 | control options. | |
452 | ||
453 | [horizontal] | |
454 | ||
455 | `cpulimit`: :: You can use this option to further limit assigned CPU time. | |
456 | Please note that this is a floating point number, so it is perfectly valid to | |
457 | assign two cores to a container, but restrict overall CPU consumption to half a | |
458 | core. | |
459 | + | |
460 | ---- | |
461 | cores: 2 | |
462 | cpulimit: 0.5 | |
463 | ---- | |
464 | ||
465 | `cpuunits`: :: This is a relative weight passed to the kernel scheduler. The | |
466 | larger the number is, the more CPU time this container gets. Number is relative | |
467 | to the weights of all the other running containers. The default is 1024. You | |
468 | can use this setting to prioritize some containers. | |
469 | ||
470 | ||
471 | [[pct_memory]] | |
472 | Memory | |
473 | ~~~~~~ | |
474 | ||
475 | [thumbnail="screenshot/gui-create-ct-memory.png"] | |
476 | ||
477 | Container memory is controlled using the cgroup memory controller. | |
478 | ||
479 | [horizontal] | |
480 | ||
481 | `memory`: :: Limit overall memory usage. This corresponds to the | |
482 | `memory.limit_in_bytes` cgroup setting. | |
483 | ||
484 | `swap`: :: Allows the container to use additional swap memory from the host | |
485 | swap space. This corresponds to the `memory.memsw.limit_in_bytes` cgroup | |
486 | setting, which is set to the sum of both value (`memory + swap`). | |
487 | ||
488 | ||
489 | [[pct_mount_points]] | |
490 | Mount Points | |
491 | ~~~~~~~~~~~~ | |
492 | ||
493 | [thumbnail="screenshot/gui-create-ct-root-disk.png"] | |
494 | ||
495 | The root mount point is configured with the `rootfs` property. You can | |
496 | configure up to 256 additional mount points. The corresponding options are | |
497 | called `mp0` to `mp255`. They can contain the following settings: | |
498 | ||
499 | include::pct-mountpoint-opts.adoc[] | |
500 | ||
501 | Currently there are three types of mount points: storage backed mount points, | |
502 | bind mounts, and device mounts. | |
503 | ||
504 | .Typical container `rootfs` configuration | |
505 | ---- | |
506 | rootfs: thin1:base-100-disk-1,size=8G | |
507 | ---- | |
508 | ||
509 | ||
510 | Storage Backed Mount Points | |
511 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
512 | ||
513 | Storage backed mount points are managed by the {pve} storage subsystem and come | |
514 | in three different flavors: | |
515 | ||
516 | - Image based: these are raw images containing a single ext4 formatted file | |
517 | system. | |
518 | - ZFS subvolumes: these are technically bind mounts, but with managed storage, | |
519 | and thus allow resizing and snapshotting. | |
520 | - Directories: passing `size=0` triggers a special case where instead of a raw | |
521 | image a directory is created. | |
522 | ||
523 | NOTE: The special option syntax `STORAGE_ID:SIZE_IN_GB` for storage backed | |
524 | mount point volumes will automatically allocate a volume of the specified size | |
525 | on the specified storage. For example, calling | |
526 | ||
527 | ---- | |
528 | pct set 100 -mp0 thin1:10,mp=/path/in/container | |
529 | ---- | |
530 | ||
531 | will allocate a 10GB volume on the storage `thin1` and replace the volume ID | |
532 | place holder `10` with the allocated volume ID, and setup the moutpoint in the | |
533 | container at `/path/in/container` | |
534 | ||
535 | ||
536 | Bind Mount Points | |
537 | ^^^^^^^^^^^^^^^^^ | |
538 | ||
539 | Bind mounts allow you to access arbitrary directories from your Proxmox VE host | |
540 | inside a container. Some potential use cases are: | |
541 | ||
542 | - Accessing your home directory in the guest | |
543 | - Accessing an USB device directory in the guest | |
544 | - Accessing an NFS mount from the host in the guest | |
545 | ||
546 | Bind mounts are considered to not be managed by the storage subsystem, so you | |
547 | cannot make snapshots or deal with quotas from inside the container. With | |
548 | unprivileged containers you might run into permission problems caused by the | |
549 | user mapping and cannot use ACLs. | |
550 | ||
551 | NOTE: The contents of bind mount points are not backed up when using `vzdump`. | |
552 | ||
553 | WARNING: For security reasons, bind mounts should only be established using | |
554 | source directories especially reserved for this purpose, e.g., a directory | |
555 | hierarchy under `/mnt/bindmounts`. Never bind mount system directories like | |
556 | `/`, `/var` or `/etc` into a container - this poses a great security risk. | |
557 | ||
558 | NOTE: The bind mount source path must not contain any symlinks. | |
559 | ||
560 | For example, to make the directory `/mnt/bindmounts/shared` accessible in the | |
561 | container with ID `100` under the path `/shared`, use a configuration line like | |
562 | `mp0: /mnt/bindmounts/shared,mp=/shared` in `/etc/pve/lxc/100.conf`. | |
563 | Alternatively, use `pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared` to | |
564 | achieve the same result. | |
565 | ||
566 | ||
567 | Device Mount Points | |
568 | ^^^^^^^^^^^^^^^^^^^ | |
569 | ||
570 | Device mount points allow to mount block devices of the host directly into the | |
571 | container. Similar to bind mounts, device mounts are not managed by {PVE}'s | |
572 | storage subsystem, but the `quota` and `acl` options will be honored. | |
573 | ||
574 | NOTE: Device mount points should only be used under special circumstances. In | |
575 | most cases a storage backed mount point offers the same performance and a lot | |
576 | more features. | |
577 | ||
578 | NOTE: The contents of device mount points are not backed up when using | |
579 | `vzdump`. | |
580 | ||
581 | ||
582 | [[pct_container_network]] | |
583 | Network | |
584 | ~~~~~~~ | |
585 | ||
586 | [thumbnail="screenshot/gui-create-ct-network.png"] | |
587 | ||
588 | You can configure up to 10 network interfaces for a single container. | |
589 | The corresponding options are called `net0` to `net9`, and they can contain the | |
590 | following setting: | |
591 | ||
592 | include::pct-network-opts.adoc[] | |
593 | ||
594 | ||
595 | [[pct_startup_and_shutdown]] | |
596 | Automatic Start and Shutdown of Containers | |
597 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
598 | ||
599 | To automatically start a container when the host system boots, select the | |
600 | option 'Start at boot' in the 'Options' panel of the container in the web | |
601 | interface or run the following command: | |
602 | ||
603 | ---- | |
604 | # pct set CTID -onboot 1 | |
605 | ---- | |
606 | ||
607 | .Start and Shutdown Order | |
608 | // use the screenshot from qemu - its the same | |
609 | [thumbnail="screenshot/gui-qemu-edit-start-order.png"] | |
610 | ||
611 | If you want to fine tune the boot order of your containers, you can use the | |
612 | following parameters: | |
613 | ||
614 | * *Start/Shutdown order*: Defines the start order priority. For example, set it | |
615 | to 1 if you want the CT to be the first to be started. (We use the reverse | |
616 | startup order for shutdown, so a container with a start order of 1 would be | |
617 | the last to be shut down) | |
618 | * *Startup delay*: Defines the interval between this container start and | |
619 | subsequent containers starts. For example, set it to 240 if you want to wait | |
620 | 240 seconds before starting other containers. | |
621 | * *Shutdown timeout*: Defines the duration in seconds {pve} should wait | |
622 | for the container to be offline after issuing a shutdown command. | |
623 | By default this value is set to 60, which means that {pve} will issue a | |
624 | shutdown request, wait 60s for the machine to be offline, and if after 60s | |
625 | the machine is still online will notify that the shutdown action failed. | |
626 | ||
627 | Please note that containers without a Start/Shutdown order parameter will | |
628 | always start after those where the parameter is set, and this parameter only | |
629 | makes sense between the machines running locally on a host, and not | |
630 | cluster-wide. | |
631 | ||
632 | Hookscripts | |
633 | ~~~~~~~~~~~ | |
634 | ||
635 | You can add a hook script to CTs with the config property `hookscript`. | |
636 | ||
637 | ---- | |
638 | # pct set 100 -hookscript local:snippets/hookscript.pl | |
639 | ---- | |
640 | ||
641 | It will be called during various phases of the guests lifetime. For an example | |
642 | and documentation see the example script under | |
643 | `/usr/share/pve-docs/examples/guest-example-hookscript.pl`. | |
644 | ||
645 | Backup and Restore | |
646 | ------------------ | |
647 | ||
648 | ||
649 | Container Backup | |
650 | ~~~~~~~~~~~~~~~~ | |
651 | ||
652 | It is possible to use the `vzdump` tool for container backup. Please refer to | |
653 | the `vzdump` manual page for details. | |
654 | ||
655 | ||
656 | Restoring Container Backups | |
657 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
658 | ||
659 | Restoring container backups made with `vzdump` is possible using the `pct | |
660 | restore` command. By default, `pct restore` will attempt to restore as much of | |
661 | the backed up container configuration as possible. It is possible to override | |
662 | the backed up configuration by manually setting container options on the | |
663 | command line (see the `pct` manual page for details). | |
664 | ||
665 | NOTE: `pvesm extractconfig` can be used to view the backed up configuration | |
666 | contained in a vzdump archive. | |
667 | ||
668 | There are two basic restore modes, only differing by their handling of mount | |
669 | points: | |
670 | ||
671 | ||
672 | ``Simple'' Restore Mode | |
673 | ^^^^^^^^^^^^^^^^^^^^^^^ | |
674 | ||
675 | If neither the `rootfs` parameter nor any of the optional `mpX` parameters are | |
676 | explicitly set, the mount point configuration from the backed up configuration | |
677 | file is restored using the following steps: | |
678 | ||
679 | . Extract mount points and their options from backup | |
680 | . Create volumes for storage backed mount points (on storage provided with the | |
681 | `storage` parameter, or default local storage if unset) | |
682 | . Extract files from backup archive | |
683 | . Add bind and device mount points to restored configuration (limited to root | |
684 | user) | |
685 | ||
686 | NOTE: Since bind and device mount points are never backed up, no files are | |
687 | restored in the last step, but only the configuration options. The assumption | |
688 | is that such mount points are either backed up with another mechanism (e.g., | |
689 | NFS space that is bind mounted into many containers), or not intended to be | |
690 | backed up at all. | |
691 | ||
692 | This simple mode is also used by the container restore operations in the web | |
693 | interface. | |
694 | ||
695 | ||
696 | ``Advanced'' Restore Mode | |
697 | ^^^^^^^^^^^^^^^^^^^^^^^^^ | |
698 | ||
699 | By setting the `rootfs` parameter (and optionally, any combination of `mpX` | |
700 | parameters), the `pct restore` command is automatically switched into an | |
701 | advanced mode. This advanced mode completely ignores the `rootfs` and `mpX` | |
702 | configuration options contained in the backup archive, and instead only uses | |
703 | the options explicitly provided as parameters. | |
704 | ||
705 | This mode allows flexible configuration of mount point settings at restore | |
706 | time, for example: | |
707 | ||
708 | * Set target storages, volume sizes and other options for each mount point | |
709 | individually | |
710 | * Redistribute backed up files according to new mount point scheme | |
711 | * Restore to device and/or bind mount points (limited to root user) | |
712 | ||
713 | ||
714 | Managing Containers with `pct` | |
715 | ------------------------------ | |
716 | ||
717 | The ``Proxmox Container Toolkit'' (`pct`) is the command line tool to manage | |
718 | {pve} containers. It enables you to create or destroy containers, as well as | |
719 | control the container execution (start, stop, reboot, migrate, etc.). It can be | |
720 | used to set parameters in the config file of a container, for example the | |
721 | network configuration or memory limits. | |
722 | ||
723 | CLI Usage Examples | |
724 | ~~~~~~~~~~~~~~~~~~ | |
725 | ||
726 | Create a container based on a Debian template (provided you have already | |
727 | downloaded the template via the web interface) | |
728 | ||
729 | ---- | |
730 | # pct create 100 /var/lib/vz/template/cache/debian-10.0-standard_10.0-1_amd64.tar.gz | |
731 | ---- | |
732 | ||
733 | Start container 100 | |
734 | ||
735 | ---- | |
736 | # pct start 100 | |
737 | ---- | |
738 | ||
739 | Start a login session via getty | |
740 | ||
741 | ---- | |
742 | # pct console 100 | |
743 | ---- | |
744 | ||
745 | Enter the LXC namespace and run a shell as root user | |
746 | ||
747 | ---- | |
748 | # pct enter 100 | |
749 | ---- | |
750 | ||
751 | Display the configuration | |
752 | ||
753 | ---- | |
754 | # pct config 100 | |
755 | ---- | |
756 | ||
757 | Add a network interface called `eth0`, bridged to the host bridge `vmbr0`, set | |
758 | the address and gateway, while it's running | |
759 | ||
760 | ---- | |
761 | # pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1 | |
762 | ---- | |
763 | ||
764 | Reduce the memory of the container to 512MB | |
765 | ||
766 | ---- | |
767 | # pct set 100 -memory 512 | |
768 | ---- | |
769 | ||
770 | ||
771 | Obtaining Debugging Logs | |
772 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
773 | ||
774 | In case `pct start` is unable to start a specific container, it might be | |
775 | helpful to collect debugging output by running `lxc-start` (replace `ID` with | |
776 | the container's ID): | |
777 | ||
778 | ---- | |
779 | # lxc-start -n ID -F -l DEBUG -o /tmp/lxc-ID.log | |
780 | ---- | |
781 | ||
782 | This command will attempt to start the container in foreground mode, to stop | |
783 | the container run `pct shutdown ID` or `pct stop ID` in a second terminal. | |
784 | ||
785 | The collected debug log is written to `/tmp/lxc-ID.log`. | |
786 | ||
787 | NOTE: If you have changed the container's configuration since the last start | |
788 | attempt with `pct start`, you need to run `pct start` at least once to also | |
789 | update the configuration used by `lxc-start`. | |
790 | ||
791 | [[pct_migration]] | |
792 | Migration | |
793 | --------- | |
794 | ||
795 | If you have a cluster, you can migrate your Containers with | |
796 | ||
797 | ---- | |
798 | # pct migrate <ctid> <target> | |
799 | ---- | |
800 | ||
801 | This works as long as your Container is offline. If it has local volumes or | |
802 | mount points defined, the migration will copy the content over the network to | |
803 | the target host if the same storage is defined there. | |
804 | ||
805 | Running containers cannot live-migrated due to techincal limitations. You can | |
806 | do a restart migration, which shuts down, moves and then starts a container | |
807 | again on the target node. As containers are very lightweight, this results | |
808 | normally only in a downtime of some hundreds of milliseconds. | |
809 | ||
810 | A restart migration can be done through the web interface or by using the | |
811 | `--restart` flag with the `pct migrate` command. | |
812 | ||
813 | A restart migration will shut down the Container and kill it after the | |
814 | specified timeout (the default is 180 seconds). Then it will migrate the | |
815 | Container like an offline migration and when finished, it starts the Container | |
816 | on the target node. | |
817 | ||
818 | [[pct_configuration]] | |
819 | Configuration | |
820 | ------------- | |
821 | ||
822 | The `/etc/pve/lxc/<CTID>.conf` file stores container configuration, where | |
823 | `<CTID>` is the numeric ID of the given container. Like all other files stored | |
824 | inside `/etc/pve/`, they get automatically replicated to all other cluster | |
825 | nodes. | |
826 | ||
827 | NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be | |
828 | unique cluster wide. | |
829 | ||
830 | .Example Container Configuration | |
831 | ---- | |
832 | ostype: debian | |
833 | arch: amd64 | |
834 | hostname: www | |
835 | memory: 512 | |
836 | swap: 512 | |
837 | net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth | |
838 | rootfs: local:107/vm-107-disk-1.raw,size=7G | |
839 | ---- | |
840 | ||
841 | The configuration files are simple text files. You can edit them using a normal | |
842 | text editor (`vi`, `nano`, etc). | |
843 | This is sometimes useful to do small corrections, but keep in mind that you | |
844 | need to restart the container to apply such changes. | |
845 | ||
846 | For that reason, it is usually better to use the `pct` command to generate and | |
847 | modify those files, or do the whole thing using the GUI. | |
848 | Our toolkit is smart enough to instantaneously apply most changes to running | |
849 | containers. This feature is called "hot plug", and there is no need to restart | |
850 | the container in that case. | |
851 | ||
852 | In cases where a change cannot be hot plugged, it will be registered as a | |
853 | pending change (shown in red color in the GUI). | |
854 | They will only be applied after rebooting the container. | |
855 | ||
856 | ||
857 | File Format | |
858 | ~~~~~~~~~~~ | |
859 | ||
860 | The container configuration file uses a simple colon separated key/value | |
861 | format. Each line has the following format: | |
862 | ||
863 | ----- | |
864 | # this is a comment | |
865 | OPTION: value | |
866 | ----- | |
867 | ||
868 | Blank lines in those files are ignored, and lines starting with a `#` character | |
869 | are treated as comments and are also ignored. | |
870 | ||
871 | It is possible to add low-level, LXC style configuration directly, for example: | |
872 | ||
873 | ---- | |
874 | lxc.init_cmd: /sbin/my_own_init | |
875 | ---- | |
876 | ||
877 | or | |
878 | ||
879 | ---- | |
880 | lxc.init_cmd = /sbin/my_own_init | |
881 | ---- | |
882 | ||
883 | The settings are passed directly to the LXC low-level tools. | |
884 | ||
885 | ||
886 | [[pct_snapshots]] | |
887 | Snapshots | |
888 | ~~~~~~~~~ | |
889 | ||
890 | When you create a snapshot, `pct` stores the configuration at snapshot time | |
891 | into a separate snapshot section within the same configuration file. For | |
892 | example, after creating a snapshot called ``testsnapshot'', your configuration | |
893 | file will look like this: | |
894 | ||
895 | .Container configuration with snapshot | |
896 | ---- | |
897 | memory: 512 | |
898 | swap: 512 | |
899 | parent: testsnaphot | |
900 | ... | |
901 | ||
902 | [testsnaphot] | |
903 | memory: 512 | |
904 | swap: 512 | |
905 | snaptime: 1457170803 | |
906 | ... | |
907 | ---- | |
908 | ||
909 | There are a few snapshot related properties like `parent` and `snaptime`. The | |
910 | `parent` property is used to store the parent/child relationship between | |
911 | snapshots. `snaptime` is the snapshot creation time stamp (Unix epoch). | |
912 | ||
913 | ||
914 | [[pct_options]] | |
915 | Options | |
916 | ~~~~~~~ | |
917 | ||
918 | include::pct.conf.5-opts.adoc[] | |
919 | ||
920 | ||
921 | Locks | |
922 | ----- | |
923 | ||
924 | Container migrations, snapshots and backups (`vzdump`) set a lock to prevent | |
925 | incompatible concurrent actions on the affected container. Sometimes you need | |
926 | to remove such a lock manually (e.g., after a power failure). | |
927 | ||
928 | ---- | |
929 | # pct unlock <CTID> | |
930 | ---- | |
931 | ||
932 | CAUTION: Only do this if you are sure the action which set the lock is no | |
933 | longer running. | |
934 | ||
935 | ||
936 | ifdef::manvolnum[] | |
937 | ||
938 | Files | |
939 | ------ | |
940 | ||
941 | `/etc/pve/lxc/<CTID>.conf`:: | |
942 | ||
943 | Configuration file for the container '<CTID>'. | |
944 | ||
945 | ||
946 | include::pve-copyright.adoc[] | |
947 | endif::manvolnum[] |