How to determine what containers use the docker volume?

Question

Suppose I have a volume and I know its name or id.

I want to determine the list of containers (their names or ids) that use the volume.

What commands can I use to retrieve this information?

I thought it can be stored in the output of docker volume inspect <id> command but it gives me nothing useful other than the mount point ("/var/lib/docker/volumes/<id>").

Israel

There may well be a more direct method, but presumably you could just iterate over all containers (i.e. output of docker ps -a) and then look at the relevant part of docker inspect. – Facture

Using @jwodder suggestion below... use xargs to pass each volume id to the docker ps... command, with... docker volume ls -q | xargs -I_ docker ps -a --filter volume=_ – Binette

Answer 1

docker ps can filter by volume to show all of the containers that mount a given volume:

docker ps -a --filter volume=VOLUME_NAME_OR_MOUNT_POINT

Reference: https://docs.docker.com/engine/reference/commandline/ps/#filtering

Aseptic

Not sure of the difference, but volumes that are only referenced as .Mounts and not .Config.Volumes (with docker container inspect) will not show up with this filter. – Effectual

If you're here for the opposite, filter works on volume ls as well: docker volume ls --filter name=container_name – Pilcomayo

In case you want to output a list of associated container names only, for using the ouput in a script for example, you can append a format parameter: docker ps -a --filter volume=VOLUME_NAME --format "{{.Names}}" – Goat

@Pilcomayo that seems to filter by volume name, not by container name. docker volume ls --filter name=volume_name. To get volumes by container name, use docker inspect --format '{{ .Mounts }}' container_name or a variation of that: #30134164 – Dewayne

@DarioSeidl Raisin's docker volume ls --filter name=container_name works for me to get volumes mounted to specified container. – Lucey

Answer 2

The script below will show each volume with the container(s) using it:

#!/bin/sh

volumes=$(docker volume ls  --format '{{.Name}}')

for volume in $volumes
do
  echo $volume
  docker ps -a --filter volume="$volume"  --format '{{.Names}}' | sed 's/^/  /'
done

Listing volumes by container is slightly trickier so it's an exercise for the reader but the above should suffice unless you have many containers/volumes.

Polygamy

Answer 3

For each volume, this script outputs the list of containers using this volume, bearing in mind that a volume may be used by several containers.

for v in $(docker volume ls --format "{{.Name}}")
do
  containers="$(docker ps -a --filter volume=$v --format '{{.Names}}' | tr '\n' ',')"
  echo "volume $v is used by $containers"
done

Ellisellison

Answer 4

This is related to jwodder suggestion, if of any help to someone. It basically gives the summary of all the volumes, in case you have more than a couple and are not sure, which is which.

import io
import subprocess
import pandas as pd


results = subprocess.run('docker volume ls', capture_output=True, text=True)

df = pd.read_csv(io.StringIO(results.stdout),
                 encoding='utf8',
                 sep="    ",
                 engine='python')

for i, row in df.iterrows():
    print(i, row['VOLUME NAME'])
    print('-' * 20)
    cmd = ['docker', 'ps', '-a', '--filter', f'volume={row["VOLUME NAME"]}']
    print(subprocess.run(cmd,
           capture_output=True, text=True).stdout)
    print()

Harman

You must run this with python 3.7 or higher. 3.6 does not have "capture_output=True" for subprocess module. – Fondue

With option shell=True, it works even better. Id est: subprocess.run('docker volume ls', capture_output=True, text=True, shell=Ture). Thanks @Oren! – Heredia