Inconsistent handling of quoted variables in .env between Compose v1 and v2

[jpetazzo]

Brief description:

Quotes in .env files aren't handled the same way between Compose v1 and Compose v2.

Specifically, with Compose v2, variables with spaces must be quoted, otherwise, they get truncated.
In Compose v1, in remember that in one case, I had to remove the quotes, because they would show up in the variable (but I can't reproduce that issue right now so it might be specific to some older versions of Compose v1?)

Steps to reproduce the issue:

Create the following files:

mkdir -p /tmp/compose-v2-envquotes
cd /tmp/compose-v2-envquotes

cat >docker-compose.yml <<EOF
version: "3"

services:
  env:
    image: alpine
    environment:
    - WITHQUOTES
    - WITHOUTQUOTES
    command: env
EOF

cat >.env <<EOF
WITHQUOTES="With quotes"
WITHOUTQUOTES=Without quotes
EOF

Then docker-compose up.

Describe the results you received:

With Compose v1, both variables are fully present:

...
env_1  | WITHQUOTES=With quotes
env_1  | WITHOUTQUOTES=Without quotes
...

With Compose v2, the variable without quotes is truncated:

...
compose-v2-envquotes-env-1  | WITHOUTQUOTES=Without
compose-v2-envquotes-env-1  | WITHQUOTES=With quotes
...

Describe the results you expected:

Identical result with both versions of Compose.

Output of docker compose version:

docker-compose version 1.29.2, build unknown
docker-py version: 5.0.2
CPython version: 3.9.7
OpenSSL version: OpenSSL 1.1.1l  24 Aug 2021

Docker Compose version v2.0.1

Similar or related issues:

This could be related to #8626 (which is also about an env issue) but it might also be a different bug, so I'm opening a separate issue.

[Shikachuu]

@ndeloof
This issue and issue #8741 are probably a godotenv problem like #8626.
Seems like this godotenv PR will fix this bug aswell.

[TheTerrasque]

I would like to point out that this goes directly against the environment file spec at https://docs.docker.com/compose/env-file/

One of the syntax rules mentioned there is:

• There is no special handling of quotation marks. This means that they are part of the VAL.

[ndeloof]

Yes, doc need to be updated for V2, see https://github.com/docker/docker.github.io/pull/13474/files#diff-8edc9c85338bc8e7c7a80ef3a0a01ec54cfad9e2ac61824e40c42c66604c3355

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically closed because it had not recent activity during the stale period.