how to get the volume size in docker-py

Question

I need to find the space occupied by a volume in a container. In order to check whether it crossed the threshold or not. Suppose a container is mounted in myvolume1 and I need to get the total space used by it, free space available on it. From this, I need to check its threshold is less than 80%. I'm using docker-py for automation purposes.

Answer 1

When you created one volume in docker using docker volume create command, it creates a persistent volume. Now this persistent volume will take space from your local system. So it depends on your local system's storage.

You can check size of your docker system.

$ docker system df
TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              3                   3                   379.8MB             237.1MB (62%)
Containers          10                  0                   731.9MB             731.9MB (100%)
Local Volumes       2                   1                   12.82kB             0B (0%)
Build Cache         0                   0                   0B                  0B

If you want to check from where your containers take storage, you can inspect your volume.

$ docker volume inspect myvol1
    {
        "CreatedAt": "2020-04-07T14:56:31+05:30",
        "Driver": "local",
        "Labels": {},
        "Mountpoint": "/var/lib/docker/volumes/myvol1/_data",
        "Name": "myvol1",
        "Options": {},
        "Scope": "local"
    }

In my case, my container takes storage from /var/lib/docker/volumes/myvol1/_data and this file is available in my local system.

Hope this will clear your doubt.