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Docker

Some additional docker commands, which might be useful. For more detailed information search the docker website https://docs.docker.com/.

Which version of docker is being used?

Bash
[ebreitmoser@awb-webapp01 how_toy]$ docker -v
Docker version 1.13.1, build 0be3e21/1.13.1

Remove all stopped containers (beware that will stop all images for all users belonging to the docker group!):

Text Only
docker container prune

See here for further information.

Otherwise beware that they can take up a lot of disk space. To check the total disk space:

Bash
df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               7.8G     0  7.8G   0% /dev
tmpfs                              1.6G  1.9M  1.6G   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   29G   20G  7.3G  74% /

...

So in this case we have a total of 29GB available of which 74% are already used.

Display information regarding the amount of disk space used by the docker daemon (see here).

Bash
[ebreitmoser@awb-webapp01 how_toy]$ docker system df
TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              20                  0                   6.42 GB             6.42 GB (100%)
Containers          0                   0                   0 B                 0 B
Local Volumes       0                   0                   0 B                 0 B

The RECLAIMABLE amount of disk space is the total size consumed by unused images. To remove

  • all stopped containers
  • all volumes not used by at least one container
  • all networks not used by at least one container
  • all dangling images

Run (that's less than all unused images! But you do NOT want to delete all images)

Bash
docker system prune

Remove one or more docker images.

First list them all, then delete the ones you want to by using their Image ID (see https://docs.docker.com/engine/reference/commandline/rmi/):

Bash
[ebreitmoser@awb-webapp01 how_toy]$ docker images
REPOSITORY                                TAG                 IMAGE ID            CREATED             SIZE
how_toy                                   latest              88aa985b958c        35 minutes ago      1.02 GB
<none>                                    <none>              44e1665e9b8f        13 hours ago        1.02 GB
<none>                                    <none>              3863d1b46f5d        14 hours ago        580 MB
then
Bash
[ebreitmoser@awb-webapp01 how_toy]$ docker image rmi -f 44e1665e9b8f 3863d1b46f5d

You see that the docker image typically tale ~1GB of space.

Runtime metrics

See https://docs.docker.com/config/containers/runmetrics/. Look which containers are currently running. Then choose one and see how many %CPUs, memory etc it is currently using on the system.

Bash
docker container ls
CONTAINER ID   IMAGE          COMMAND                  CREATED          STATUS          PORTS                                       NAMES
d1644205de1c   stm_industry   "R -e 'rmarkdown::ru..."   18 minutes ago   Up 18 minutes   0.0.0.0:20000->3838/tcp                     jovial_goldwasser

docker stats d1644205de1c

CONTAINER ID   NAME                CPU %     MEM USAGE / LIMIT     MEM %     NET I/O         BLOCK I/O     PIDS
d1644205de1c   jovial_goldwasser   2.86%     221.9MiB / 15.63GiB   1.39%     353kB / 986kB   0B / 1.06MB   4