mirror of
https://github.com/docker/cli.git
synced 2025-08-27 13:42:00 +03:00
Cobra allows for aliases to be defined for a command, but only allows these to be defined at the same level (for example, `docker image ls` as alias for `docker image list`). Our CLI has some commands that are available both as a top-level shorthand as well as `docker <object> <verb>` subcommands. For example, `docker ps` is a shorthand for `docker container ps` / `docker container ls`. This patch introduces a custom "aliases" annotation that can be used to print all available aliases for a command. While this requires these aliases to be defined manually, in practice the list of aliases rarely changes, so maintenance should be minimal. As a convention, we could consider the first command in this list to be the canonical command, so that we can use this information to add redirects in our documentation in future. Before this patch: docker images --help Usage: docker images [OPTIONS] [REPOSITORY[:TAG]] List images Options: -a, --all Show all images (default hides intermediate images) ... With this patch: docker images --help Usage: docker images [OPTIONS] [REPOSITORY[:TAG]] List images Aliases: docker image ls, docker image list, docker images Options: -a, --all Show all images (default hides intermediate images) ... Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
121 lines
3.4 KiB
Markdown
121 lines
3.4 KiB
Markdown
---
|
|
title: "exec"
|
|
description: "The exec command description and usage"
|
|
keywords: "command, container, run, execute"
|
|
---
|
|
|
|
# exec
|
|
|
|
```markdown
|
|
Usage: docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
|
|
|
|
Execute a command in a running container
|
|
|
|
Aliases:
|
|
docker container exec, docker exec
|
|
|
|
Options:
|
|
-d, --detach Detached mode: run command in the background
|
|
--detach-keys Override the key sequence for detaching a container
|
|
-e, --env=[] Set environment variables
|
|
--env-file Read in a file of environment variables
|
|
--help Print usage
|
|
-i, --interactive Keep STDIN open even if not attached
|
|
--privileged Give extended privileges to the command
|
|
-t, --tty Allocate a pseudo-TTY
|
|
-u, --user Username or UID (format: <name|uid>[:<group|gid>])
|
|
-w, --workdir Working directory inside the container
|
|
```
|
|
|
|
## Description
|
|
|
|
The `docker exec` command runs a new command in a running container.
|
|
|
|
The command started using `docker exec` only runs while the container's primary
|
|
process (`PID 1`) is running, and it is not restarted if the container is
|
|
restarted.
|
|
|
|
COMMAND will run in the default directory of the container. If the
|
|
underlying image has a custom directory specified with the WORKDIR directive
|
|
in its Dockerfile, this will be used instead.
|
|
|
|
COMMAND should be an executable, a chained or a quoted command
|
|
will not work. Example: `docker exec -ti my_container "echo a && echo b"` will
|
|
not work, but `docker exec -ti my_container sh -c "echo a && echo b"` will.
|
|
|
|
## Examples
|
|
|
|
### Run `docker exec` on a running container
|
|
|
|
First, start a container.
|
|
|
|
```console
|
|
$ docker run --name ubuntu_bash --rm -i -t ubuntu bash
|
|
```
|
|
|
|
This will create a container named `ubuntu_bash` and start a Bash session.
|
|
|
|
Next, execute a command on the container.
|
|
|
|
```console
|
|
$ docker exec -d ubuntu_bash touch /tmp/execWorks
|
|
```
|
|
|
|
This will create a new file `/tmp/execWorks` inside the running container
|
|
`ubuntu_bash`, in the background.
|
|
|
|
Next, execute an interactive `bash` shell on the container.
|
|
|
|
```console
|
|
$ docker exec -it ubuntu_bash bash
|
|
```
|
|
|
|
This will create a new Bash session in the container `ubuntu_bash`.
|
|
|
|
Next, set environment variables in the current bash session.
|
|
|
|
```console
|
|
$ docker exec -it -e VAR_A=1 -e VAR_B=2 ubuntu_bash bash
|
|
```
|
|
|
|
This will create a new Bash session in the container `ubuntu_bash` with environment
|
|
variables `$VAR_A` and `$VAR_B` set to "1" and "2" respectively. Note that these
|
|
environment variables will only be valid on the current Bash session.
|
|
|
|
By default `docker exec` command runs in the same working directory set when container was created.
|
|
|
|
```console
|
|
$ docker exec -it ubuntu_bash pwd
|
|
/
|
|
```
|
|
|
|
You can select working directory for the command to execute into
|
|
|
|
```console
|
|
$ docker exec -it -w /root ubuntu_bash pwd
|
|
/root
|
|
```
|
|
|
|
|
|
### Try to run `docker exec` on a paused container
|
|
|
|
If the container is paused, then the `docker exec` command will fail with an error:
|
|
|
|
```console
|
|
$ docker pause test
|
|
|
|
test
|
|
|
|
$ docker ps
|
|
|
|
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
|
|
1ae3b36715d2 ubuntu:latest "bash" 17 seconds ago Up 16 seconds (Paused) test
|
|
|
|
$ docker exec test ls
|
|
|
|
FATA[0000] Error response from daemon: Container test is paused, unpause the container before exec
|
|
|
|
$ echo $?
|
|
1
|
|
```
|