CODEWITHSUNDEEP
docker
Petro Ivanenko
Petro Ivanenko

Reputation: 727

Volumes in the host system

I can create a docker volume using a relative path:

version: '3'

services:
  db:
    image: postgres
    environment:
      POSTGRES_PASSWORD: ${DB_PASS}
    volumes:
      - ./dbdata:/var/lib/postgresql/data
    ports:
      - '5432:5432'

Then, dbdata will be available on my WSL 2, and I will be able to enter it (with sudo su) and inspect its contents.

Yet, when I run docker volume ls, I see only json below, which does not look like my dbdata volume at all:

[
    {
        "CreatedAt": "2020-11-03T09:19:37Z",
        "Driver": "local",
        "Labels": null,
        "Mountpoint": "/var/lib/docker/volumes/5d668164c5bcdf4cc01e4c8fbc20cc1155f757d4ba06dc5118fa2d0a0b5efb9b/_data",
        "Name": "5d668164c5bcdf4cc01e4c8fbc20cc1155f757d4ba06dc5118fa2d0a0b5efb9b",
        "Options": null,
        "Scope": "local"
    }
]

But here I found this quote.

When you create a volume, it is stored within a directory on the Docker host

So my docker volumes should not be on my WSL 2 filesystem at all, they should reside on the Docker host instead. Then why do I see my volumes inside WSL?

Upvotes: 0

Views: 42

Answers (1)

Milan Markovic
Milan Markovic

Reputation: 1360

Because, the quote you referenced applies to named volumes. That is, the volumes created either by docker volume create command or volumes defined in docker-compose.yml in the root volumes section, but not in volumes section inside a specific service.

More specifically, that syntax creates a bind mount and not a named volume.

Upvotes: 1

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