How to use environment variables inside docker .env file?

Question

I have a cache folder and the path is stored in an evironment variable: $LOCAL_CACHE (export LOCAL_CACHE=/home/me/path/to/any/cache/folder)

Now I want to append some additional folders inside my .env file:

My .env file:

LOCAL_COMPOSER_DIR=${LOCAL_CACHE}/composer
LOCAL_NPM_DIR=${LOCAL_CACHE}/npm
LOCAL_BOWER_DIR=${LOCAL_CACHE}/bower

My docker_compose.yml looks like that:

version: '2'
services:
  composer:
    env_file: .env
    image: composer/composer
    volumes:
      - ./src:${APP_ROOT}
      - ${LOCAL_COMPOSER_DIR}:/composer
    working_dir: ${APP_ROOT}

When I start the service with docker-compose run composer instal. ... it stops with following error: ERROR: Named volume "$LOCAL_CACHE"/composer":/composer:rw" is used in service "composer" but no declaration was found in the volumes section.

I'm not shure but it seems, the .env file doesn't support the use of variables.

which OS is on ? OSX? or Linux? – Chenna V May 12 '17 at 18:47 — Chenna V, May 12 '17 at 18:47

score 0 · Answer 1 · edited May 23 '17 at 10:31

0

Yes. Into .env file you can not use variables. Suddenly but true. Actual for docker compose version 1.8.

But you can use variables into docker-compose.yml file like

volumes:
  - ${LOCAL_COMPOSER_DIR}/${CACHE_DIR}:/composer/${CACHE_DIR}

This answer suggest us another way.

edited May 23 '17 at 10:31

Community

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answered Jan 26 '17 at 18:35

Bukharov Sergey

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Sometimes you have different systems with different environment variables. My idea was, to normalize the environment variables inside the .env.DIST files and not inside the docker-compose.yml. – Kevin Feb 21 '17 at 14:36

How to use environment variables inside docker .env file?

1 Answers1