Docker-compose env file not working

Question

I'm writing as docker-compose file to up MySQL instance and want to use few variable from env file: here are the files actually look like:

docker-compose.yml

version: '3.3'
services:
  db:
    image: mysql
    restart: always
    env_file:
      - ./imran.env
    environment:
      MYSQL_ROOT_PASSWORD: ${PASS}
    ports:
      - ${PORT1}: ${PORT2}

imran.env

PASS=imran123
PORT1=3306
PORT2=3306

Instead of working correct i'm getting following errors:

WARNING: The PASS variable is not set. Defaulting to a blank string.
WARNING: The PORT2 variable is not set. Defaulting to a blank string.
ERROR: The Compose file './docker-compose.yml' is invalid because:
services.db.ports contains unsupported option: '${PORT1}

Please Help

Answer 1

You have some issues in your docker-compose.yaml file:

A:

A space symbol between ports values. It should be without a space:

ports:
  - ${PORT1}:${PORT2}

B:

You need to use .env file in folder where docker-compose.yaml is in order to declaring default environment variables for both docker-compose.yaml file and docker container. env_file section is used to put values into container only.

So, you should do the following:

1.

Re-name file with ENV variables to .env:

mv imran.env .env

2.

Use the following docker-compose.yaml after:

version: '3.3'
services:
  db:
    image: mysql
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: ${PASS}
    ports:
      - ${PORT1}:${PORT2}