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80c0adcb | 1 | [[chapter_pct]] |
0c6b782f | 2 | ifdef::manvolnum[] |
b2f242ab | 3 | pct(1) |
7e2fdb3d | 4 | ====== |
38fd0958 | 5 | include::attributes.txt[] |
5f09af76 DM |
6 | :pve-toplevel: |
7 | ||
0c6b782f DM |
8 | NAME |
9 | ---- | |
10 | ||
11 | pct - Tool to manage Linux Containers (LXC) on Proxmox VE | |
12 | ||
13 | ||
49a5e11c | 14 | SYNOPSIS |
0c6b782f DM |
15 | -------- |
16 | ||
17 | include::pct.1-synopsis.adoc[] | |
18 | ||
19 | DESCRIPTION | |
20 | ----------- | |
21 | endif::manvolnum[] | |
22 | ||
23 | ifndef::manvolnum[] | |
24 | Proxmox Container Toolkit | |
25 | ========================= | |
38fd0958 | 26 | include::attributes.txt[] |
194d2f29 | 27 | :pve-toplevel: |
0c6b782f | 28 | endif::manvolnum[] |
5f09af76 | 29 | ifdef::wiki[] |
cb84ed18 | 30 | :title: Linux Container |
5f09af76 | 31 | endif::wiki[] |
4a2ae9ed DM |
32 | |
33 | Containers are a lightweight alternative to fully virtualized | |
34 | VMs. Instead of emulating a complete Operating System (OS), containers | |
35 | simply use the OS of the host they run on. This implies that all | |
36 | containers use the same kernel, and that they can access resources | |
37 | from the host directly. | |
38 | ||
39 | This is great because containers do not waste CPU power nor memory due | |
40 | to kernel emulation. Container run-time costs are close to zero and | |
41 | usually negligible. But there are also some drawbacks you need to | |
42 | consider: | |
43 | ||
44 | * You can only run Linux based OS inside containers, i.e. it is not | |
a8e99754 | 45 | possible to run FreeBSD or MS Windows inside. |
4a2ae9ed | 46 | |
a8e99754 | 47 | * For security reasons, access to host resources needs to be |
4a2ae9ed | 48 | restricted. This is done with AppArmor, SecComp filters and other |
a8e99754 | 49 | kernel features. Be prepared that some syscalls are not allowed |
4a2ae9ed DM |
50 | inside containers. |
51 | ||
52 | {pve} uses https://linuxcontainers.org/[LXC] as underlying container | |
53 | technology. We consider LXC as low-level library, which provides | |
a8e99754 | 54 | countless options. It would be too difficult to use those tools |
4a2ae9ed DM |
55 | directly. Instead, we provide a small wrapper called `pct`, the |
56 | "Proxmox Container Toolkit". | |
57 | ||
a8e99754 | 58 | The toolkit is tightly coupled with {pve}. That means that it is aware |
4a2ae9ed DM |
59 | of the cluster setup, and it can use the same network and storage |
60 | resources as fully virtualized VMs. You can even use the {pve} | |
61 | firewall, or manage containers using the HA framework. | |
62 | ||
63 | Our primary goal is to offer an environment as one would get from a | |
64 | VM, but without the additional overhead. We call this "System | |
65 | Containers". | |
66 | ||
99d2e25b | 67 | NOTE: If you want to run micro-containers (with docker, rkt, ...), it |
70a42028 | 68 | is best to run them inside a VM. |
4a2ae9ed DM |
69 | |
70 | ||
99f6ae1a DM |
71 | Technology Overview |
72 | ------------------- | |
73 | ||
74 | * LXC (https://linuxcontainers.org/) | |
75 | ||
76 | * Integrated into {pve} graphical user interface (GUI) | |
77 | ||
78 | * Easy to use command line tool `pct` | |
79 | ||
80 | * Access via {pve} REST API | |
81 | ||
82 | * lxcfs to provide containerized /proc file system | |
83 | ||
84 | * AppArmor/Seccomp to improve security | |
85 | ||
86 | * CRIU: for live migration (planned) | |
87 | ||
88 | * Use latest available kernels (4.4.X) | |
89 | ||
90 | * Image based deployment (templates) | |
91 | ||
92 | * Use {pve} storage library | |
93 | ||
94 | * Container setup from host (network, DNS, storage, ...) | |
95 | ||
96 | ||
4a2ae9ed DM |
97 | Security Considerations |
98 | ----------------------- | |
99 | ||
100 | Containers use the same kernel as the host, so there is a big attack | |
101 | surface for malicious users. You should consider this fact if you | |
102 | provide containers to totally untrusted people. In general, fully | |
a8e99754 | 103 | virtualized VMs provide better isolation. |
4a2ae9ed DM |
104 | |
105 | The good news is that LXC uses many kernel security features like | |
106 | AppArmor, CGroups and PID and user namespaces, which makes containers | |
107 | usage quite secure. We distinguish two types of containers: | |
108 | ||
5eba0743 FG |
109 | |
110 | Privileged Containers | |
4a2ae9ed DM |
111 | ~~~~~~~~~~~~~~~~~~~~~ |
112 | ||
113 | Security is done by dropping capabilities, using mandatory access | |
114 | control (AppArmor), SecComp filters and namespaces. The LXC team | |
115 | considers this kind of container as unsafe, and they will not consider | |
116 | new container escape exploits to be security issues worthy of a CVE | |
117 | and quick fix. So you should use this kind of containers only inside a | |
118 | trusted environment, or when no untrusted task is running as root in | |
119 | the container. | |
120 | ||
5eba0743 FG |
121 | |
122 | Unprivileged Containers | |
4a2ae9ed DM |
123 | ~~~~~~~~~~~~~~~~~~~~~~~ |
124 | ||
a8e99754 | 125 | This kind of containers use a new kernel feature called user |
5eba0743 | 126 | namespaces. The root UID 0 inside the container is mapped to an |
4a2ae9ed DM |
127 | unprivileged user outside the container. This means that most security |
128 | issues (container escape, resource abuse, ...) in those containers | |
129 | will affect a random unprivileged user, and so would be a generic | |
a8e99754 | 130 | kernel security bug rather than an LXC issue. The LXC team thinks |
4a2ae9ed DM |
131 | unprivileged containers are safe by design. |
132 | ||
3bd9d0cf | 133 | |
53e3cd6f DM |
134 | Guest Operating System Configuration |
135 | ------------------------------------ | |
136 | ||
137 | We normally try to detect the operating system type inside the | |
138 | container, and then modify some files inside the container to make | |
139 | them work as expected. Here is a short list of things we do at | |
140 | container startup: | |
141 | ||
142 | set /etc/hostname:: to set the container name | |
143 | ||
144 | modify /etc/hosts:: to allow lookup of the local hostname | |
145 | ||
146 | network setup:: pass the complete network setup to the container | |
147 | ||
148 | configure DNS:: pass information about DNS servers | |
149 | ||
150 | adapt the init system:: for example, fix the number of spawned getty processes | |
151 | ||
152 | set the root password:: when creating a new container | |
153 | ||
154 | rewrite ssh_host_keys:: so that each container has unique keys | |
155 | ||
156 | randomize crontab:: so that cron does not start at the same time on all containers | |
157 | ||
158 | Changes made by {PVE} are enclosed by comment markers: | |
159 | ||
160 | ---- | |
161 | # --- BEGIN PVE --- | |
162 | <data> | |
163 | # --- END PVE --- | |
164 | ---- | |
165 | ||
166 | Those markers will be inserted at a reasonable location in the | |
167 | file. If such a section already exists, it will be updated in place | |
168 | and will not be moved. | |
169 | ||
170 | Modification of a file can be prevented by adding a `.pve-ignore.` | |
171 | file for it. For instance, if the file `/etc/.pve-ignore.hosts` | |
172 | exists then the `/etc/hosts` file will not be touched. This can be a | |
173 | simple empty file creatd via: | |
174 | ||
175 | # touch /etc/.pve-ignore.hosts | |
176 | ||
177 | Most modifications are OS dependent, so they differ between different | |
178 | distributions and versions. You can completely disable modifications | |
179 | by manually setting the `ostype` to `unmanaged`. | |
180 | ||
181 | OS type detection is done by testing for certain files inside the | |
182 | container: | |
183 | ||
184 | Ubuntu:: inspect /etc/lsb-release (`DISTRIB_ID=Ubuntu`) | |
185 | ||
186 | Debian:: test /etc/debian_version | |
187 | ||
188 | Fedora:: test /etc/fedora-release | |
189 | ||
190 | RedHat or CentOS:: test /etc/redhat-release | |
191 | ||
192 | ArchLinux:: test /etc/arch-release | |
193 | ||
194 | Alpine:: test /etc/alpine-release | |
195 | ||
196 | Gentoo:: test /etc/gentoo-release | |
197 | ||
198 | NOTE: Container start fails if the configured `ostype` differs from the auto | |
199 | detected type. | |
200 | ||
201 | ||
80c0adcb | 202 | [[pct_container_images]] |
d61bab51 DM |
203 | Container Images |
204 | ---------------- | |
205 | ||
8c1189b6 FG |
206 | Container images, sometimes also referred to as ``templates'' or |
207 | ``appliances'', are `tar` archives which contain everything to run a | |
d61bab51 | 208 | container. You can think of it as a tidy container backup. Like most |
8c1189b6 | 209 | modern container toolkits, `pct` uses those images when you create a |
d61bab51 DM |
210 | new container, for example: |
211 | ||
212 | pct create 999 local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz | |
213 | ||
26ca7ff5 | 214 | {pve} itself ships a set of basic templates for most common |
8c1189b6 | 215 | operating systems, and you can download them using the `pveam` (short |
d61bab51 DM |
216 | for {pve} Appliance Manager) command line utility. You can also |
217 | download https://www.turnkeylinux.org/[TurnKey Linux] containers using | |
218 | that tool (or the graphical user interface). | |
219 | ||
3a6fa247 DM |
220 | Our image repositories contain a list of available images, and there |
221 | is a cron job run each day to download that list. You can trigger that | |
222 | update manually with: | |
223 | ||
224 | pveam update | |
225 | ||
226 | After that you can view the list of available images using: | |
227 | ||
228 | pveam available | |
229 | ||
8c1189b6 FG |
230 | You can restrict this large list by specifying the `section` you are |
231 | interested in, for example basic `system` images: | |
3a6fa247 DM |
232 | |
233 | .List available system images | |
234 | ---- | |
235 | # pveam available --section system | |
236 | system archlinux-base_2015-24-29-1_x86_64.tar.gz | |
237 | system centos-7-default_20160205_amd64.tar.xz | |
238 | system debian-6.0-standard_6.0-7_amd64.tar.gz | |
239 | system debian-7.0-standard_7.0-3_amd64.tar.gz | |
240 | system debian-8.0-standard_8.0-1_amd64.tar.gz | |
241 | system ubuntu-12.04-standard_12.04-1_amd64.tar.gz | |
242 | system ubuntu-14.04-standard_14.04-1_amd64.tar.gz | |
243 | system ubuntu-15.04-standard_15.04-1_amd64.tar.gz | |
244 | system ubuntu-15.10-standard_15.10-1_amd64.tar.gz | |
245 | ---- | |
246 | ||
a8e99754 | 247 | Before you can use such a template, you need to download them into one |
8c1189b6 | 248 | of your storages. You can simply use storage `local` for that |
3a6fa247 DM |
249 | purpose. For clustered installations, it is preferred to use a shared |
250 | storage so that all nodes can access those images. | |
251 | ||
252 | pveam download local debian-8.0-standard_8.0-1_amd64.tar.gz | |
253 | ||
24f73a63 | 254 | You are now ready to create containers using that image, and you can |
8c1189b6 | 255 | list all downloaded images on storage `local` with: |
24f73a63 DM |
256 | |
257 | ---- | |
258 | # pveam list local | |
259 | local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz 190.20MB | |
260 | ---- | |
261 | ||
a8e99754 | 262 | The above command shows you the full {pve} volume identifiers. They include |
24f73a63 | 263 | the storage name, and most other {pve} commands can use them. For |
5eba0743 | 264 | example you can delete that image later with: |
24f73a63 DM |
265 | |
266 | pveam remove local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz | |
3a6fa247 | 267 | |
d61bab51 | 268 | |
80c0adcb | 269 | [[pct_container_storage]] |
70a42028 DM |
270 | Container Storage |
271 | ----------------- | |
272 | ||
273 | Traditional containers use a very simple storage model, only allowing | |
274 | a single mount point, the root file system. This was further | |
8c1189b6 FG |
275 | restricted to specific file system types like `ext4` and `nfs`. |
276 | Additional mounts are often done by user provided scripts. This turned | |
a8e99754 | 277 | out to be complex and error prone, so we try to avoid that now. |
70a42028 DM |
278 | |
279 | Our new LXC based container model is more flexible regarding | |
280 | storage. First, you can have more than a single mount point. This | |
281 | allows you to choose a suitable storage for each application. For | |
282 | example, you can use a relatively slow (and thus cheap) storage for | |
283 | the container root file system. Then you can use a second mount point | |
284 | to mount a very fast, distributed storage for your database | |
285 | application. | |
286 | ||
287 | The second big improvement is that you can use any storage type | |
288 | supported by the {pve} storage library. That means that you can store | |
8c1189b6 FG |
289 | your containers on local `lvmthin` or `zfs`, shared `iSCSI` storage, |
290 | or even on distributed storage systems like `ceph`. It also enables us | |
291 | to use advanced storage features like snapshots and clones. `vzdump` | |
a8e99754 | 292 | can also use the snapshot feature to provide consistent container |
70a42028 DM |
293 | backups. |
294 | ||
295 | Last but not least, you can also mount local devices directly, or | |
296 | mount local directories using bind mounts. That way you can access | |
297 | local storage inside containers with zero overhead. Such bind mounts | |
a8e99754 | 298 | also provide an easy way to share data between different containers. |
70a42028 | 299 | |
eeecce95 | 300 | |
9e44e493 DM |
301 | Mount Points |
302 | ~~~~~~~~~~~~ | |
eeecce95 | 303 | |
01639994 FG |
304 | The root mount point is configured with the `rootfs` property, and you can |
305 | configure up to 10 additional mount points. The corresponding options | |
306 | are called `mp0` to `mp9`, and they can contain the following setting: | |
307 | ||
308 | include::pct-mountpoint-opts.adoc[] | |
309 | ||
9e44e493 DM |
310 | Currently there are basically three types of mount points: storage backed |
311 | mount points, bind mounts and device mounts. | |
312 | ||
5eba0743 | 313 | .Typical container `rootfs` configuration |
4c3b5c77 DM |
314 | ---- |
315 | rootfs: thin1:base-100-disk-1,size=8G | |
316 | ---- | |
317 | ||
318 | ||
5eba0743 | 319 | Storage Backed Mount Points |
4c3b5c77 | 320 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
01639994 | 321 | |
9e44e493 | 322 | Storage backed mount points are managed by the {pve} storage subsystem and come |
eeecce95 WB |
323 | in three different flavors: |
324 | ||
5eba0743 | 325 | - Image based: these are raw images containing a single ext4 formatted file |
eeecce95 | 326 | system. |
5eba0743 | 327 | - ZFS subvolumes: these are technically bind mounts, but with managed storage, |
eeecce95 WB |
328 | and thus allow resizing and snapshotting. |
329 | - Directories: passing `size=0` triggers a special case where instead of a raw | |
330 | image a directory is created. | |
331 | ||
4c3b5c77 | 332 | |
5eba0743 | 333 | Bind Mount Points |
4c3b5c77 | 334 | ^^^^^^^^^^^^^^^^^ |
01639994 | 335 | |
9baca183 FG |
336 | Bind mounts allow you to access arbitrary directories from your Proxmox VE host |
337 | inside a container. Some potential use cases are: | |
338 | ||
339 | - Accessing your home directory in the guest | |
340 | - Accessing an USB device directory in the guest | |
acccc49b | 341 | - Accessing an NFS mount from the host in the guest |
9baca183 | 342 | |
eeecce95 | 343 | Bind mounts are considered to not be managed by the storage subsystem, so you |
9baca183 | 344 | cannot make snapshots or deal with quotas from inside the container. With |
eeecce95 | 345 | unprivileged containers you might run into permission problems caused by the |
9baca183 FG |
346 | user mapping and cannot use ACLs. |
347 | ||
8c1189b6 | 348 | NOTE: The contents of bind mount points are not backed up when using `vzdump`. |
eeecce95 | 349 | |
6b707f2c FG |
350 | WARNING: For security reasons, bind mounts should only be established |
351 | using source directories especially reserved for this purpose, e.g., a | |
352 | directory hierarchy under `/mnt/bindmounts`. Never bind mount system | |
353 | directories like `/`, `/var` or `/etc` into a container - this poses a | |
9baca183 FG |
354 | great security risk. |
355 | ||
356 | NOTE: The bind mount source path must not contain any symlinks. | |
357 | ||
358 | For example, to make the directory `/mnt/bindmounts/shared` accessible in the | |
359 | container with ID `100` under the path `/shared`, use a configuration line like | |
8c1189b6 FG |
360 | `mp0: /mnt/bindmounts/shared,mp=/shared` in `/etc/pve/lxc/100.conf`. |
361 | Alternatively, use `pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared` to | |
9baca183 | 362 | achieve the same result. |
6b707f2c | 363 | |
4c3b5c77 | 364 | |
5eba0743 | 365 | Device Mount Points |
4c3b5c77 | 366 | ^^^^^^^^^^^^^^^^^^^ |
fe154a4f | 367 | |
7432d78e FG |
368 | Device mount points allow to mount block devices of the host directly into the |
369 | container. Similar to bind mounts, device mounts are not managed by {PVE}'s | |
370 | storage subsystem, but the `quota` and `acl` options will be honored. | |
371 | ||
372 | NOTE: Device mount points should only be used under special circumstances. In | |
373 | most cases a storage backed mount point offers the same performance and a lot | |
374 | more features. | |
375 | ||
8c1189b6 | 376 | NOTE: The contents of device mount points are not backed up when using `vzdump`. |
01639994 | 377 | |
4c3b5c77 | 378 | |
5eba0743 | 379 | FUSE Mounts |
4c3b5c77 | 380 | ~~~~~~~~~~~ |
01639994 FG |
381 | |
382 | WARNING: Because of existing issues in the Linux kernel's freezer | |
383 | subsystem the usage of FUSE mounts inside a container is strongly | |
384 | advised against, as containers need to be frozen for suspend or | |
385 | snapshot mode backups. | |
fe154a4f | 386 | |
01639994 FG |
387 | If FUSE mounts cannot be replaced by other mounting mechanisms or storage |
388 | technologies, it is possible to establish the FUSE mount on the Proxmox host | |
389 | and use a bind mount point to make it accessible inside the container. | |
390 | ||
01639994 | 391 | |
5eba0743 | 392 | Using Quotas Inside Containers |
04c569f6 | 393 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
d6ed3622 | 394 | |
9e44e493 DM |
395 | Quotas allow to set limits inside a container for the amount of disk |
396 | space that each user can use. This only works on ext4 image based | |
397 | storage types and currently does not work with unprivileged | |
398 | containers. | |
d6ed3622 | 399 | |
9e44e493 DM |
400 | Activating the `quota` option causes the following mount options to be |
401 | used for a mount point: | |
402 | `usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0` | |
d6ed3622 | 403 | |
9e44e493 DM |
404 | This allows quotas to be used like you would on any other system. You |
405 | can initialize the `/aquota.user` and `/aquota.group` files by running | |
d6ed3622 | 406 | |
9e44e493 DM |
407 | ---- |
408 | quotacheck -cmug / | |
409 | quotaon / | |
410 | ---- | |
d6ed3622 | 411 | |
166e63d6 FG |
412 | and edit the quotas via the `edquota` command. Refer to the documentation |
413 | of the distribution running inside the container for details. | |
414 | ||
9e44e493 DM |
415 | NOTE: You need to run the above commands for every mount point by passing |
416 | the mount point's path instead of just `/`. | |
417 | ||
d6ed3622 | 418 | |
5eba0743 | 419 | Using ACLs Inside Containers |
04c569f6 | 420 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
6c60aebf | 421 | |
5eba0743 | 422 | The standard Posix **A**ccess **C**ontrol **L**ists are also available inside containers. |
6c60aebf EK |
423 | ACLs allow you to set more detailed file ownership than the traditional user/ |
424 | group/others model. | |
d6ed3622 | 425 | |
04c569f6 | 426 | |
80c0adcb | 427 | [[pct_container_network]] |
04c569f6 DM |
428 | Container Network |
429 | ----------------- | |
430 | ||
bac8c385 | 431 | You can configure up to 10 network interfaces for a single |
8c1189b6 | 432 | container. The corresponding options are called `net0` to `net9`, and |
bac8c385 DM |
433 | they can contain the following setting: |
434 | ||
435 | include::pct-network-opts.adoc[] | |
04c569f6 DM |
436 | |
437 | ||
51e33128 FG |
438 | Backup and Restore |
439 | ------------------ | |
440 | ||
5eba0743 | 441 | |
2175e37b FG |
442 | Container Backup |
443 | ~~~~~~~~~~~~~~~~ | |
444 | ||
8c1189b6 FG |
445 | It is possible to use the `vzdump` tool for container backup. Please |
446 | refer to the `vzdump` manual page for details. | |
447 | ||
51e33128 | 448 | |
2175e37b FG |
449 | Restoring Container Backups |
450 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
451 | ||
8c1189b6 FG |
452 | Restoring container backups made with `vzdump` is possible using the |
453 | `pct restore` command. By default, `pct restore` will attempt to restore as much | |
2175e37b FG |
454 | of the backed up container configuration as possible. It is possible to override |
455 | the backed up configuration by manually setting container options on the command | |
8c1189b6 | 456 | line (see the `pct` manual page for details). |
2175e37b | 457 | |
8c1189b6 | 458 | NOTE: `pvesm extractconfig` can be used to view the backed up configuration |
2175e37b FG |
459 | contained in a vzdump archive. |
460 | ||
461 | There are two basic restore modes, only differing by their handling of mount | |
462 | points: | |
463 | ||
4c3b5c77 | 464 | |
8c1189b6 FG |
465 | ``Simple'' Restore Mode |
466 | ^^^^^^^^^^^^^^^^^^^^^^^ | |
2175e37b FG |
467 | |
468 | If neither the `rootfs` parameter nor any of the optional `mpX` parameters | |
469 | are explicitly set, the mount point configuration from the backed up | |
470 | configuration file is restored using the following steps: | |
471 | ||
472 | . Extract mount points and their options from backup | |
473 | . Create volumes for storage backed mount points (on storage provided with the | |
474 | `storage` parameter, or default local storage if unset) | |
475 | . Extract files from backup archive | |
476 | . Add bind and device mount points to restored configuration (limited to root user) | |
477 | ||
478 | NOTE: Since bind and device mount points are never backed up, no files are | |
479 | restored in the last step, but only the configuration options. The assumption | |
480 | is that such mount points are either backed up with another mechanism (e.g., | |
481 | NFS space that is bind mounted into many containers), or not intended to be | |
482 | backed up at all. | |
483 | ||
484 | This simple mode is also used by the container restore operations in the web | |
485 | interface. | |
486 | ||
4c3b5c77 | 487 | |
8c1189b6 FG |
488 | ``Advanced'' Restore Mode |
489 | ^^^^^^^^^^^^^^^^^^^^^^^^^ | |
2175e37b FG |
490 | |
491 | By setting the `rootfs` parameter (and optionally, any combination of `mpX` | |
8c1189b6 | 492 | parameters), the `pct restore` command is automatically switched into an |
2175e37b FG |
493 | advanced mode. This advanced mode completely ignores the `rootfs` and `mpX` |
494 | configuration options contained in the backup archive, and instead only | |
495 | uses the options explicitly provided as parameters. | |
496 | ||
497 | This mode allows flexible configuration of mount point settings at restore time, | |
498 | for example: | |
499 | ||
500 | * Set target storages, volume sizes and other options for each mount point | |
501 | individually | |
502 | * Redistribute backed up files according to new mount point scheme | |
503 | * Restore to device and/or bind mount points (limited to root user) | |
504 | ||
51e33128 | 505 | |
8c1189b6 | 506 | Managing Containers with `pct` |
04c569f6 DM |
507 | ------------------------------ |
508 | ||
8c1189b6 | 509 | `pct` is the tool to manage Linux Containers on {pve}. You can create |
04c569f6 DM |
510 | and destroy containers, and control execution (start, stop, migrate, |
511 | ...). You can use pct to set parameters in the associated config file, | |
512 | like network configuration or memory limits. | |
513 | ||
5eba0743 | 514 | |
04c569f6 DM |
515 | CLI Usage Examples |
516 | ~~~~~~~~~~~~~~~~~~ | |
517 | ||
518 | Create a container based on a Debian template (provided you have | |
5eba0743 | 519 | already downloaded the template via the web interface) |
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520 | |
521 | pct create 100 /var/lib/vz/template/cache/debian-8.0-standard_8.0-1_amd64.tar.gz | |
522 | ||
523 | Start container 100 | |
524 | ||
525 | pct start 100 | |
526 | ||
527 | Start a login session via getty | |
528 | ||
529 | pct console 100 | |
530 | ||
531 | Enter the LXC namespace and run a shell as root user | |
532 | ||
533 | pct enter 100 | |
534 | ||
535 | Display the configuration | |
536 | ||
537 | pct config 100 | |
538 | ||
8c1189b6 | 539 | Add a network interface called `eth0`, bridged to the host bridge `vmbr0`, |
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540 | set the address and gateway, while it's running |
541 | ||
542 | pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1 | |
543 | ||
544 | Reduce the memory of the container to 512MB | |
545 | ||
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546 | pct set 100 -memory 512 |
547 | ||
04c569f6 | 548 | |
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549 | Obtaining Debugging Logs |
550 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
551 | ||
552 | In case `pct start` is unable to start a specific container, it might be | |
553 | helpful to collect debugging output by running `lxc-start` (replace `ID` with | |
554 | the container's ID): | |
555 | ||
556 | lxc-start -n ID -F -l DEBUG -o /tmp/lxc-ID.log | |
557 | ||
558 | This command will attempt to start the container in foreground mode, to stop the container run `pct shutdown ID` or `pct stop ID` in a second terminal. | |
559 | ||
560 | The collected debug log is written to `/tmp/lxc-ID.log`. | |
561 | ||
562 | NOTE: If you have changed the container's configuration since the last start | |
563 | attempt with `pct start`, you need to run `pct start` at least once to also | |
564 | update the configuration used by `lxc-start`. | |
565 | ||
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566 | |
567 | [[pct_configuration]] | |
568 | Configuration | |
569 | ------------- | |
570 | ||
571 | The `/etc/pve/lxc/<CTID>.conf` file stores container configuration, | |
572 | where `<CTID>` is the numeric ID of the given container. Like all | |
573 | other files stored inside `/etc/pve/`, they get automatically | |
574 | replicated to all other cluster nodes. | |
575 | ||
576 | NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be | |
577 | unique cluster wide. | |
578 | ||
579 | .Example Container Configuration | |
580 | ---- | |
581 | ostype: debian | |
582 | arch: amd64 | |
583 | hostname: www | |
584 | memory: 512 | |
585 | swap: 512 | |
586 | net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth | |
587 | rootfs: local:107/vm-107-disk-1.raw,size=7G | |
588 | ---- | |
589 | ||
590 | Those configuration files are simple text files, and you can edit them | |
591 | using a normal text editor (`vi`, `nano`, ...). This is sometimes | |
592 | useful to do small corrections, but keep in mind that you need to | |
593 | restart the container to apply such changes. | |
594 | ||
595 | For that reason, it is usually better to use the `pct` command to | |
596 | generate and modify those files, or do the whole thing using the GUI. | |
597 | Our toolkit is smart enough to instantaneously apply most changes to | |
598 | running containers. This feature is called "hot plug", and there is no | |
599 | need to restart the container in that case. | |
600 | ||
601 | ||
602 | File Format | |
603 | ~~~~~~~~~~~ | |
604 | ||
605 | Container configuration files use a simple colon separated key/value | |
606 | format. Each line has the following format: | |
607 | ||
608 | ----- | |
609 | # this is a comment | |
610 | OPTION: value | |
611 | ----- | |
612 | ||
613 | Blank lines in those files are ignored, and lines starting with a `#` | |
614 | character are treated as comments and are also ignored. | |
615 | ||
616 | It is possible to add low-level, LXC style configuration directly, for | |
617 | example: | |
618 | ||
619 | lxc.init_cmd: /sbin/my_own_init | |
620 | ||
621 | or | |
622 | ||
623 | lxc.init_cmd = /sbin/my_own_init | |
624 | ||
625 | Those settings are directly passed to the LXC low-level tools. | |
626 | ||
627 | ||
628 | [[pct_snapshots]] | |
629 | Snapshots | |
630 | ~~~~~~~~~ | |
631 | ||
632 | When you create a snapshot, `pct` stores the configuration at snapshot | |
633 | time into a separate snapshot section within the same configuration | |
634 | file. For example, after creating a snapshot called ``testsnapshot'', | |
635 | your configuration file will look like this: | |
636 | ||
637 | .Container configuration with snapshot | |
638 | ---- | |
639 | memory: 512 | |
640 | swap: 512 | |
641 | parent: testsnaphot | |
642 | ... | |
643 | ||
644 | [testsnaphot] | |
645 | memory: 512 | |
646 | swap: 512 | |
647 | snaptime: 1457170803 | |
648 | ... | |
649 | ---- | |
650 | ||
651 | There are a few snapshot related properties like `parent` and | |
652 | `snaptime`. The `parent` property is used to store the parent/child | |
653 | relationship between snapshots. `snaptime` is the snapshot creation | |
654 | time stamp (Unix epoch). | |
655 | ||
656 | ||
657 | [[pct_options]] | |
658 | Options | |
659 | ~~~~~~~ | |
660 | ||
661 | include::pct.conf.5-opts.adoc[] | |
662 | ||
663 | ||
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664 | Locks |
665 | ----- | |
666 | ||
667 | Container migrations, snapshots and backups (`vzdump`) set a lock to | |
668 | prevent incompatible concurrent actions on the affected container. Sometimes | |
669 | you need to remove such a lock manually (e.g., after a power failure). | |
670 | ||
671 | pct unlock <CTID> | |
672 | ||
673 | CAUTION: Only do that if you are sure the action which set the lock is | |
674 | no longer running. | |
675 | ||
fe57a420 | 676 | |
0c6b782f | 677 | ifdef::manvolnum[] |
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678 | |
679 | Files | |
680 | ------ | |
681 | ||
682 | `/etc/pve/lxc/<CTID>.conf`:: | |
683 | ||
684 | Configuration file for the container '<CTID>'. | |
685 | ||
686 | ||
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687 | include::pve-copyright.adoc[] |
688 | endif::manvolnum[] | |
689 | ||
690 | ||
691 | ||
692 | ||
693 | ||
694 | ||
695 |