common used docker commands, list all, remove all containers, delete all images

To list all containers by container ID

docker ps -aq

stop all running containers

docker stop $(docker ps -aq)

To remove all containers

docker rm $(docker ps -aq)

To remove all imagees

docker rmi $(docker images -aq)

You might encounter this error

Error response from daemon: conflict: unable to delete 5e7a80b3348c (must be forced) – image is referenced in multiple repositories

Error response from daemon: conflict: unable to delete 5e7a80b3348c (must be forced) – image is referenced in multiple repositories

docker rmi $(docker images -q) --force

Background information:

You can see the containers on your computer using

  • docker container ls

Example output:

  • CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
  • 3477a4dcdce2 docker.elastic.co/elasticsearch/elasticsearch-oss:6.7.1 “/usr/local/bin/dock…” 2 days ago Up 2 days 0.0.0.0:9200->9200/tcp, 9300/tcp elasticsearch1
  • 67997f002f15 appbaseio/dejavu “http-server ‘-p 135…” 2 days ago Up 2 days 0.0.0.0:1358->1358/tcp dejavu

As we can see, two containers are currently running on this computer.

For each container, the IMAGE column shows us which image the container is running. For example, the second container is running on the appbaseio/dejavu image.

When we tell docker to show us all images currently listed on the computer:

  • $ docker image ls -a
  • REPOSITORY TAG IMAGE ID CREATED SIZE
  • <none> <none> 39ac507bd271 11 days ago 962MB
  • <none> <none> 6a2c829a5d4f 11 days ago 962MB
  • docker.elastic.co/elasticsearch/elasticsearch-oss 6.7.1 c91b419ac445 3 weeks ago 682MB
  • pypy 3 75e018538e96 4 weeks ago 962MB
  • node 10 64c810caf95a 4 weeks ago 899MB
  • appbaseio/dejavu latest 47b8375dc541 2 months ago 141MB
  • risingstack/alpine 3.4-v4.4.4-3.6.1 2d384efd00ab 2 years ago 247MB

We can immediately see that there are way more images than containers

There are four main reasons for that:

  • Docker keeps old versions of containers, they are not automatically deleted. In this example, there are two versions of docker.elastic.co/elasticsearch/elasticsearch-oss: Version 6.7.1 and version 7.0.0 even though I’m currently only using version 6.7.1. According to the list, version 7.0.0 takes up an additional 682 Megabytes of space on my SSD but note that this number may not be accurate (see layered images below)
  • Docker does not automatically delete images that you no longer use (e.g. if you used a an image just for a quick test but don’t use it any more)
  • Docker uses layered images. This means that an image like appbaseio/dejavu is not standalone but is (usually) based on some underlying image like ubuntu or debian. In most cases there are many layers (typically around 5-10) of an image due to the way they are built. While this leads to less disk space being consumed since some images are used by multiple “daughter” images, this still leads to a lot of images laying around on your drive, often including unused intermediary images.
  • In case you build docker images yourself, especially in case you are creating your own Dockerfile, during development often a lot of images are generated (representing intermediary versions of the software you are developing)

In order to delete an image that you no longer need, use the docker image rm <image ID> command. Copy the image ID from the IMAGE ID column of the output of docker image ls as shown above.

For example, in order to delete the version 7.0.0 image of elasticsearch, use

  • $ docker image rm 0e92b9e5fe1e
  • Untagged: docker.elastic.co/elasticsearch/elasticsearch-oss:7.0.0
  • Untagged: docker.elastic.co/elasticsearch/[email protected]:e9ab1f4c2ffbc7054dab91e8dc7fd9a56d53cce734098910d876eb14849b1ba3
  • Deleted: sha256:0e92b9e5fe1e0949f5174ed86d9cbc3c2a041df493453f82b6c044ff78c7d17b
  • Deleted: sha256:c2a552806b86aba72a6e6ea5efaaa295286e8b0cf42a14d799428e58f20e7090
  • Deleted: sha256:71e7a706f7c03f0c7add24844f7b311edf83838ef383a877bcb94684b011893d
  • Deleted: sha256:d43e5d351c26273e43b11f6937cb9a3192d856b4e083acfbc14b8500056221f2
  • Deleted: sha256:f3a2ae77ca96f2f55300b00beedbf14ade0a27bf29c395dcbf84b5bf02ef80ad
  • Deleted: sha256:5d7f2d83e59c0684b4a94ab5f6479d798444bdca8fe6c813f7ef6188cdd12ce5
  • Deleted: sha256:cc16decd0c6f218c3a21749e747d43deced9e8929e8db0b6050dd4102301651a

As you can see from the output, this will not only delete the ElasticSearch image 0e92b9e5fe1e itself but also all the other images that image depended on (which are not also used by any other image).