Docker-Docs/_data/engine-cli/docker_exec.yaml

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2020-11-18 13:32:27 -05:00
command: docker exec
short: Run a command in a running container
long: |-
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.
usage: docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
pname: docker
plink: docker.yaml
options:
- option: detach
shorthand: d
value_type: bool
default_value: "false"
description: 'Detached mode: run command in the background'
deprecated: false
experimental: false
experimentalcli: false
kubernetes: false
swarm: false
- option: detach-keys
value_type: string
description: Override the key sequence for detaching a container
deprecated: false
experimental: false
experimentalcli: false
kubernetes: false
swarm: false
- option: env
shorthand: e
value_type: list
description: Set environment variables
deprecated: false
min_api_version: "1.25"
experimental: false
experimentalcli: false
kubernetes: false
swarm: false
- option: interactive
shorthand: i
value_type: bool
default_value: "false"
description: Keep STDIN open even if not attached
deprecated: false
experimental: false
experimentalcli: false
kubernetes: false
swarm: false
- option: privileged
value_type: bool
default_value: "false"
description: Give extended privileges to the command
deprecated: false
experimental: false
experimentalcli: false
kubernetes: false
swarm: false
- option: tty
shorthand: t
value_type: bool
default_value: "false"
description: Allocate a pseudo-TTY
deprecated: false
experimental: false
experimentalcli: false
kubernetes: false
swarm: false
- option: user
shorthand: u
value_type: string
description: 'Username or UID (format: <name|uid>[:<group|gid>])'
deprecated: false
experimental: false
experimentalcli: false
kubernetes: false
swarm: false
- option: workdir
shorthand: w
value_type: string
description: Working directory inside the container
deprecated: false
min_api_version: "1.35"
experimental: false
experimentalcli: false
kubernetes: false
swarm: false
examples: |-
### Run `docker exec` on a running container
First, start a container.
```bash
$ 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.
```bash
$ 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.
```bash
$ docker exec -it ubuntu_bash bash
```
This will create a new Bash session in the container `ubuntu_bash`.
Next, set an environment variable in the current bash session.
```bash
$ docker exec -it -e VAR=1 ubuntu_bash bash
```
This will create a new Bash session in the container `ubuntu_bash` with environment
variable `$VAR` set to "1". Note that this environment variable 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.
```bash
$ docker exec -it ubuntu_bash pwd
/
```
You can select working directory for the command to execute into
```bash
$ 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:
```bash
$ 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
```
deprecated: false
experimental: false
experimentalcli: false
kubernetes: false
swarm: false