Env files parsing

[present-g]

We still have a problem with different parsing of env files in docker compose and docker run

Files:

.env.test

TEST_VAR='{"key": "value"}'

test.Dockerfile

FROM ubuntu

CMD echo "$TEST_VAR"

test.docker-compose.yaml

services:
  service:
    build:
      dockerfile: test.Dockerfile
    env_file: .env.test
    image: test-image

Execution:

docker compose -f test.docker-compose.yaml up --build => {"key": "value"}
docker run --env-file .env.test test-image => '{"key": "value"}'

We need unified results, otherwise, apps may not work correctly

Docker version 27.1.1, build 6312585
Docker Compose version v2.29.1-desktop.1

Originally posted by @present-g in #2854 (comment)

[ndeloof]

Docker Compose .env file parser is not strictly equivalent to the one used by docker run, because the former manages variable interpolation while the latter just consider values as raw string, including quotes.

There's no workaround for this. A possible fix would be to give you an option to explicitly request env file to be loaded without compose to manage values:

services:
  service:
    env_file: 
      path: .env.test
      format: raw # default is to parse with interpolation

[present-g]

Docker Compose .env file parser is not strictly equivalent to the one used by docker run, because the former manages variable interpolation while the latter just consider values as raw string, including quotes.

And that's the issue. Docker's primary goal is to ensure that everything runs consistently across all environments.

format: raw - is it working now? I've never seen that before

[ndeloof]

introducing format is my proposal to offer a fix for this issue, it has to be implemented