Volumes

Mount

Here we have directory in the repo at root as foo. This is mounted in the container as /root/bar/foo.

volumes:
  - "./foo:/root/bar"

Relative paths

Be sure to use dotslash before a directory name.

./foo

Note that setting directory as:

foo

That will be assumed to be a named volume.

It will expand to be this path on your host. Which will probably not exist and will give an error.

/root/foo

Relative paths

• ~/foo
• /foo

Examples

Samples from compose file docs.

Short syntax

• docker-compose.yml

    volumes:
      # Just specify a path and let the Engine create a volume
      - /var/lib/mysql
  
      # Specify an absolute path mapping
      - /opt/data:/var/lib/mysql
  
      # Path on the host, relative to the Compose file
      - ./cache:/tmp/cache
  
      # User-relative path
      - ~/configs:/etc/configs/:ro
  
      # Named volume
      - datavolume:/var/lib/mysql
  

Named volumes

• docker-compose.yml

    version: "3.8"
  
    services:
      web:
        image: nginx:alpine
          
        volumes:
          - type: volume
            source: mydata
            target: /data
            volume:
              nocopy: true
                
          - type: bind
            source: ./static
            target: /opt/app/static
  
      db:
        image: postgres:latest
          
        volumes:
          - "/var/run/postgres/postgres.sock:/var/run/postgres/postgres.sock"
          - "dbdata:/var/lib/postgresql/data"
  
    volumes:
      mydata:
      dbdata:
  

Another example, from the Docker Compose file specification.

• docker-compose.yml

    services:
      backend:
        image: awesome/backend
          
        volumes:
          - type: volume
            source: db-data
            target: /data
            volume:
              nocopy: true
                
          - type: bind
            source: /var/run/postgres/postgres.sock
            target: /var/run/postgres/postgres.sock
  
    volumes:
      db-data: