Docker + Bash

Some tips and helpers for Docker :

Remove all containers

We use docker ps --all to list all containers.

We use docker rm --force <container> to remove a container.

To remove all containers silently we can execute :

$ docker rm --force $(docker ps --all --quiet) &>/dev/null

Let’s make our life easier by adding a bash function in the ~/.bashrc file :

drc means docker remove containers.

# docker: remove all containers (running, exited, ...) silently
drc() { docker rm --force $(docker ps --all --quiet) &>/dev/null; }

Now you can reload the run commands file and execute the drc function :

$ . ~/.bashrc
$ drc

Remove all images

We use docker images --all to list all images.

We use docker rmi --force <image> to remove an image.

To remove all images silently we can execute :

$ docker rmi --force $(docker images --all --quiet)  &>/dev/null

Let’s make our life easier by adding a bash function in the ~/.bashrc file :

dri means docker remove images.

We can notice that the function invokes the drc function.

# docker: remove all images silently
dri() { drc; docker rmi --force $(docker images --all --quiet) &>/dev/null; }

Now you can reload the run commands file and execute the dri function :

$ . ~/.bashrc
$ dri

Remove dangling images

Docker images consist of multiple layers. Dangling images are layers that have no relationship to any tagged images. They no longer serve a purpose and consume disk space.

We use docker images --filter dangling=true to list untagged images.

Untagged images are those with the <none> label :

$ docker images --filter dangling=true
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
<none>              <none>              71b672f83ce6        About an hour ago   5.55MB
<none>              <none>              e47393887344        About an hour ago   5.55MB
<none>              <none>              c038e3c9b034        About an hour ago   5.55MB

To remove all untagged images silently we can execute :

$ docker rmi --force $(docker images --filter dangling=true --quiet)  &>/dev/null

Let’s make our life easier by adding a bash function in the ~/.bashrc file :

drd means docker remove dangling images.

# docker: remove all dangling (untagged) images silently
drd() { docker rmi --force $(docker images --filter dangling=true --quiet)  &>/dev/null; }

List the last 10 tags of a docker image

We can see the images of alpine on the docker hub site.

We can get the JSON data of the 10 latests images from the registry API page.

We can list the latests tags from the terminal by using curl and jq :

# the last 10 tags of the `alpine` image
$ curl --silent 'https://registry.hub.docker.com/v2/repositories/library/alpine/tags/' \
    | jq --raw-output '."results"[]["name"]'

Let’s make our life easier by adding a bash function in the ~/.bashrc file :

dlt means docker list tags.

# docker: list the last 10 tags of an image.
# sample usage: `dlt alpine`
dlt() { curl --silent "https://registry.hub.docker.com/v2/repositories/library/$1/tags/" | jq --raw-output '."results"[]["name"]' 2>/dev/null; }