Hi,

I have an Elixir 1.15.7 application. At first, it was intended to be installed only on Windows. Therefore I configured mix.iex with Windows-specific environment variable ALLUSERSPROFILE in my config provider:

defmodule MyApp.MixProject do
  use Mix.Project

  def project do
    [
      ...
      releases: releases(),
    ]
  end

  ...

  defp releases do
    [
      myapp: [
        include_executables_for: [:windows],
        config_providers: [
          {MyApp.Config.TOMLConfigProvider,
           "%ALLUSERSPROFILE%\\MyCompany\\MyApp\\config.toml"}
        ]
      ]
    ]
  end
end

Now, I need to provide releases for linux as well and I first would like to get rid of the Windows-specific environment variable in mix.iex.

I have adapted my config provider to be used like so:

defp releases do
  [
    myapp: [
      include_executables_for: [:unix, :windows],
      config_providers: [
        {MyApp.Config.TOMLConfigProvider,
         {:system, "MYAPP_CONFIG_DIR", "/configuration.toml"}}
      ]
    ]
  ]
end

and I have created a rel/env.bat.eex:

@echo off

set MYAPP_CONFIG_DIR=%ALLUSERSPROFILE%\MyCompany\MyApp

With that in place, I can successfully launch my release with:

C:\MyCompany\MyApp>dir
 Volume in drive C is OS
 Volume Serial Number is ************

 Directory of C:\MyCompany\MyApp

17.01.2024  15:34    <DIR>          .
17.01.2024  15:01    <DIR>          ..
17.01.2024  15:33    <DIR>          bin
17.01.2024  15:33    <DIR>          erts-13.2.2.5
17.01.2024  15:34    <DIR>          lib
17.01.2024  15:34    <DIR>          releases
17.01.2024  15:34           451 643 unins000.dat
17.01.2024  15:33         3 223 613 unins000.exe
               2 File(s)      3 675 256 bytes
               6 Dir(s)  1 530 448 859 136 bytes free

C:\MyCompany\MyApp>bin\myapp.bat start

But the goal is to install the Windows service and after doing so (i.e. bin\myapp.bat install), the problem is that the service stops immediately after it started:

C:\MyCompany\MyApp>erts-13.2.2.5\bin\erlsrv.exe start myapp_myapp
erts-13.2.2.5\bin\erlsrv.exe: Service myapp_myapp started.

I am pretty sure the env.bat is not executed when starting the Windows service. I have no log to confirm this but when I use an absolute path in my config provider instead of the {:system, "MYAPP_CONFIG_DIR", "/configuration.toml"} tuple, then the service starts and I can successfully access my web app.

Is mix release’s env.bat suppose to work with Windows service?