Compose: Unable to bind Windows environment variables to Docker Compose Envs

[dougrathbone]

Per SO post with noluck: https://stackoverflow.com/questions/45527969/unable-to-bind-windows-environment-variables-to-docker-compose-environment

I currently have a compose file for a Windows .Net service, and I want to be able to pass through a user-space environment variable:

Set from powershell:

powershell [Environment]::SetEnvironmentVariable(\"PREVIOUSLY_SET_WINDOWS_ENV_VARIABLE\", $env:computername, \"User\")

(i've also tried "machine" space env variables as well using the above).

To test after running the above:
echo %PREVIOUSLY_SET_WINDOWS_ENV_VARIABLE% from a new command prompt window.

Docker compose file:

    services:
      myservice.commandline:
        image: myservice.commandline:dev
        build:
          args:
            source: ${DOCKER_BUILD_SOURCE}
        volumes:
          - .\myservice.commandline:C:\app
          - ~\msvsmon:C:\msvsmon:ro
        entrypoint: powershell -Command [System.Threading.Thread]::Sleep([System.Threading.Timeout]::Infinite)
        environment:
          - MY_VARIABLE_NAME=${PREVIOUSLY_SET_WINDOWS_ENV_VARIABLE}
        labels:
          - "com.microsoft.visualstudio.targetoperatingsystem=windows"

This does not work - the environment variable shows as blank.

- MY_VARIABLE_NAME=${PREVIOUSLY_SET_WINDOWS_ENV_VARIABLE} doesn't work.

Is it possible to pass a windows environment variable through to a Docker Compose environment variable? This is easily accomplished using the *nix version of compose, so hoping i've just missed something.

Background:

• ${PREVIOUSLY_SET_WINDOWS_ENV_VARIABLE} doesn't work.
• $PREVIOUSLY_SET_WINDOWS_ENV_VARIABLE doesn't work.
• $(PREVIOUSLY_SET_WINDOWS_ENV_VARIABLE) doesn't work.
• ${%PREVIOUSLY_SET_WINDOWS_ENV_VARIABLE%} doesn't work.

[shin-]

Have you tried setting a process-level environment variable instead, like $env:PREVIOUSLY_SET_ENVIRONMENT_VARIABLE = $env:computername ?

[dougrathbone]

using the "env" prefix doesn't fix this.

environment variables don't appear to work in Windows even if set at the system level using the System advanced options menus.

[artisticcheese]

This works for me with no issues.

version: '3.2'
services:
   greg:
      image: microsoft/windowsservercore
      environment: 
        - "ContainerEnvVariable=${HostEnvVariable}"
      networks:
        - nat
networks:
  nat:
    external: true

$env:HostEnvVariable = "hello"

[dougrathbone]

This worked after upgrading my docker compose files to 3.2 - the default installed by Visual Studio is 2.1

[samiraguiar]

I'm having the same issue, but in my case I cannot migrate my files to 3.2 since I need to use the mem_limit option. My workaround was to mount a script that sets the variables and then run it inside the container on start, but I'd appreciate if there were a better way.