CODEWITHSUNDEEP
dockerdocker-composeenv-file
Jin
Jin

Reputation: 31

Even if I define env_file in docker compose, it is not loaded

At first, I placed .env in the root directory, defined env_file as - .env, and set APP_PORT, and it worked fine. After that, I changed the placement to secret/.env, but even if I define env_file as above, the port remains at the default 8000. I tried various things, such as restarting the container, but it didn't work.

services:
  app:
    container_name: "app"
    build:
      context: .
      dockerfile: Dockerfile
    env_file:
      - secrets/.env
    ports:
      - "${APP_PORT:-8000}:8000"
    volumes:
      - .:/app
    restart: always

I would be grateful for any advice.

Upvotes: 0

Views: 32

Answers (1)

David Maze
David Maze

Reputation: 158908

Compose has two layers of environment-variable handling. It can substitute variables in the Compose file itself, and it defines the environment for each individual container. env_file: defines only the per-container environment, but you're trying to use its value to substitute a value in the Compose file; it doesn't work for this.

The docker compose base command defines an --env-file option, so you can use this to provide the file.

docker compose --env-file secrets/.env up -d

If the file only contains values that are used directly in the Compose file (potentially including the right-hand side of environment:, but you don't expect these values to be visible inside the container otherwise) then you can remove env_file:.

For single values like this, and especially if you have a default value in the Compose file, you can also just set the environment variable on the host.

export APP_PORT=8765
docker compose up -d

In both cases it may be helpful to ensure these values are consistently set. If you use docker compose --env-file, you may need to use it on every Compose invocation, lest it decide your containers have incorrect configuration and need to be rebuilt with default settings.

Upvotes: 0

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