Why are docker volumes not created?

Question

I am running Flask and MySQL using docker-compose.yaml.

Although I have specified a volume, the volume has not been created.

Why is this?

docker-compose.yaml

version: '3'
services: 
  api:
      build: python
      container_name: api_server_flask
      ports:
        - "5000:5000"
      tty: true
      environment:
        TZ: Asia/Tokyo
        FLASK_APP: app.py
      depends_on:
        - db
      networks:
        - app_flask
  db:  
    build: mysql
    container_name: db_server_flask
    ports:
      - '3306:3306'
    environment:
      MYSQL_ROOT_PASSWORD: pass
      MYSQL_DATABASE: testdb
      TZ: Asia/Tokyo
    volumes:
      - ./db-flask-data/:/var/lib/mysql
    command: mysqld
    networks:
      - app_flask
volumes:
  db-flask-data:
networks:
  app_flask:
    driver: bridge

Zied Yazidi · Answer

You need to remove the relative path as follows:

volumes:
  - db-flask-data/:/var/lib/mysql

It is explained here: https://docs.docker.com/storage/volumes/#use-a-volume-with-docker-compose

Actually, you are creating a named volume under /var/lib/docker/volumes/db-flask-data when you are specifying the following command:

volumes:
  db-flask-data:

Why are docker volumes not created?

1 Answers