How to override config with env var on Windows?

[cocowalla]

I'm trying to setup the otel collector as a Windows Service. As part of that, I want to load part of the config using an OTEL_AUTH environment variable:

exporters:
  logging:
    verbosity: detailed
  otlp/openobserve:
      endpoint: apm.example.com:5081
      headers:
        Authorization: Basic ${env:OTEL_AUTH}

I tried putting this in a .env file alongside the otel exe, but it doesn't seem to use this file. I also don't want to set this as a system-wide env var, since it contains credentials.

How can I get the otel collector to read this env var from another file? Or can I somehow pass it on the command line?

[pjanotti]

@cocowalla while searching other thing I found this discussion. I suppose that by now you already found the solution. For the record here is a suggestion on how to do it:

• Create a REG_MULTI_SZ registry value named Environment under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<service-name-that-you-used-for-the-otel-collector>

On this multistring value each line represents an environment variable visible only to the specific service. The syntax of each line is the name of the environment variable followed by an =, everything after the sign until the end of the line is the value of the environment variable.

For example, for OTEL_AUTH add a line like:

OTEL_AUTH=<your-value-for-otel-auth>

[cocowalla]

@pjanotti yes, I did eventually figure it out, but I totally forgot to update this discussion with the solution, so thanks for that! 🙏