[BUG] FILE__varname is not parsed in the container

[brumik]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

When I set:

environment:
  FILE__PASS: /run/secrets/ddclient_password

I can see the evironment variable FILE__PASS set in the container to the path but the PASS is undefined.

Documentation about the feature

Expected Behavior

The PASS contains the contents of the /run/secrets/ddclient_password file.

Steps To Reproduce

1. Create a secret in ./secrets/ddclient/password as a simple string xxxxxxx for example

secrets:
  ddclient_password:
    file: ./secrets/ddclient/password

services:
  ddclient:
    image: lscr.io/linuxserver/ddclient:latest
    container_name: ddclient
    environment:
      TZ: $TZ
      PUID: $PUID
      PGID: $PGID
      FILE__PASS: /run/secrets/ddclient_password
    secrets:
      - ddclient_password
    volumes:
      - ../appdata/ddclient:/config
    restart: unless-stopped

3. After starting the container jump into it docker compose exec ddclient sh
4. See that PASS variable is undefined

Environment

- OS: Ubutnu & NixOs
- How docker service was installed: official documetation / nixos config by virtualization

CPU architecture

x86-64

Docker creation

`docker compose up ddclient`

Container logs

If we set up the env variable to be used as password then following code:

# ddclient.conf
password_env=PASS

ddclient  | WARNING:  null password specified for host xxxxx

[github-actions]

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[thespad]

Please provide the full container log

[brumik]

I am sorry as I was doing the export I realized there is a trailing newline at the end of file. This newline did not show up anywhere (vim/vscode/gedit) and could not remove it with tr. I was able to remove it with truncate -s -1 <<file>>. Now the variable is set correctly.

Incredible how much time I spent on a simple issue like this. Thank you.