Quadlet environment / .env syntax interpolation is not working

[orchard0]

Issue Description

Environment interpolation does not work in .env files set using EnvironmentFile option nor in the Environment option in .container files.

Steps to reproduce the issue

example.container:

[Container]
...
Environment=POSTGRES_USER=example 
Environment=AUTHENTIK_POSTGRESQL__USER=${POSTGRES_USER}
...

Nor does it work in an attached .env file set using the EnvironmentFile option:

POSTGRES_PASSWORD=mypassword
AUTHENTIK_POSTGRESQL__PASSWORD=${POSTGRES_PASSWORD}

Describe the results you received

Interpolation does not occur.

AUTHENTIK_POSTGRESQL__PASSWORD and AUTHENTIK_POSTGRESQL__USER are not set.

Describe the results you expected

AUTHENTIK_POSTGRESQL__USER to be set to example
AUTHENTIK_POSTGRESQL__PASSWORD to be set to mypassword

podman info output

Podman version 5.4.0

Podman in a container

No

Privileged Or Rootless

Rootless

Upstream Latest Release

No

Additional environment details

No response

Additional information

No response

[ygalblum]

Not sure that this is a Quadlet issue. I've tried the following:

$ podman run --rm -e POSTGRES_USER=example -e AUTHENTIK_POSTGRESQL__USER=${POSTGRES_USER} fedora:42 /bin/bash -c "env"
HOSTNAME=d9168b7254b8
PWD=/
container=oci
HOME=/root
SHLVL=0
POSTGRES_USER=example
PATH=/usr/local/bin:/usr/bin
AUTHENTIK_POSTGRESQL__USER=
_=/usr/bin/env

You can see that AUTHENTIK_POSTGRESQL__USER is set to nothing.

[orchard0]

I've been migrating from a systemd compose.yaml setup and expected this would work. Is interpolation out of the question then?