Conflicting PGPASSWORD env var on Windows

[bkoelman]

As can be seen here, the PGPASSWORD environment variable is defined on Windows. Its default value of root conflicts with the default value postgres from action-setup-postgres. So it would be nice to set this variable accordingly from this GitHub action. It took me several hours to figure this out, as I couldn't find why our tests failed.

[bkoelman]

This applies to PGUSER as well; see https://github.com/actions/runner-images/blob/main/images/win/scripts/Installers/Install-PostgreSQL.ps1#L6-L7. Linux and macOS do not set these environment variables.

[ikalnytskyi]

Hey @bkoelman,

Thank you for reporting. I'm sorry I got to your issue 4 months after it was reported.

I deliberately decided that I don't want to set PGUSER, PGPASSWORD and PGHOST for the rest of the job since it may have undesired consequences similar to what you have reported, especially when someone is looking to deal with multiple PostgreSQL users. It's advised to opt into superuser using a service name or a connection uri exposed by this action explicitly. See 75b3f77 for details. Setting PGUSER and PGPASSWORD would be a step backward.

The README file for the Windows runner says nothing about setting PGPASSWORD (see EnvironmentVariables property), but as you pointed out, their installation script does it anyway. I'm not sure what to do here, to be honest. We can document this as a known gotcha, or simply "unset" the environment variable to make behavior consistent between OS-es. Let me think about it.