Docker quick reference

docker.md

Show docker images

$ docker images
REPOSITORY                                                                                          TAG                 IMAGE ID            CREATED             SIZE
docker-registry-default.gsa2.lightbend.com/lightbend/exercise_002_cluster_base_move_to_artery_tcp   1.3.0               42e9a5268b85        15 hours ago        267MB

Removing an image

$ docker rmi 42e9a5268b85
Error response from daemon: conflict: unable to delete 42e9a5268b85 (must be forced) - image is being used by stopped container bedb9492efec
HypriotOS/armv7: akkapi@node-1 in ~
$ docker rm bedb9492efec
bedb9492efec
HypriotOS/armv7: akkapi@node-1 in ~
$ docker rmi 42e9a5268b85
Untagged: docker-registry-default.gsa2.lightbend.com/lightbend/exercise_002_cluster_base_move_to_artery_tcp:1.3.0
Untagged: docker-registry-default.gsa2.lightbend.com/lightbend/exercise_002_cluster_base_move_to_artery_tcp@sha256:ccd53438d82a994dabb18782931715d1f87775e4602b90f87cf130e5c6f9b0a8
Deleted: sha256:42e9a5268b859e830f5965e46f6e58291ffd8bbfab401b3a70c5355f2f5cb578
Deleted: sha256:f10f2f00880d5a049b38d3606e53ef96f97a6b3b1c8436a908a1874383f65890
HypriotOS/armv7: akkapi@node-1 in ~

In some cases, docker rm may fail saying that the image is in use. Use the -f option to force-remove.

Show running containers & Container ID

$ docker ps
CONTAINER ID        IMAGE                                                                                                     COMMAND                  CREATED             STATUS              PORTS               NAMES
bedb9492efec        docker-registry-default.gsa2.lightbend.com/lightbend/exercise_002_cluster_base_move_to_artery_tcp:1.3.0   "/opt/docker/bin/exe…"   14 hours ago        Up 3 minutes                            akkapi_akka_cluster_1
HypriotOS/armv7: akkapi@node-1 in ~

Logging into a running container

$ docker exec -it -entrypoint bedb9492efec sh

Copying files from a docker container

Example:

docker cp bedb9492efec:/opt/docker/someFile .