Support installation from custom NPM registry via .npmrc

[Eynorey]

Related to #177.

This PR adds support for custom NPM registry configurations, allowing the action to install PNPM from there.

With this, the action copies a potential .npmrc into the destination directory from where PNPM runs self-install, respecting potential custom registry configurations.

# My custom registry
registry = https://my-registry.my-company.com/

Note

I was also considering an action parameter, but this feels more natural - if you are already using a custom registry via .npmrc, then you'll likely want your package manager to be fetched form there as well.

But I could also see a parameter being helpful for some setups, perhaps even acting as an override to the .npmrc registry configuration. Maybe as a follow-up?

Any feedback is greatly appreciated!

[benquarmby]

❤️ Love this.

My opinion doesn't matter a great deal, but I'm going to give it anyway 😜

[Eynorey]

@zkochan @KSXGitHub would you mind taking a look when you get a chance, thanks!

[Ellosaur]

I have an environment where using the public registry is not an option due to security constraints, so being able to configure this installation to use our private registry is essential so thanks for doing this!

[KSXGitHub]

Alternatively, pnpm itself uses the package ini (with @types/ini for typing) to parse INI. That could be used instead of trying to reinvent the parser.

[zkochan]

Just copy the .npmrc file from GITHUB_WORKSPACE to dest. Installation is performed by a pnpm version bundled with the action. It can read the .npmrc file.

[Eynorey]

Thank you everyone for taking a look, and thank you for the feedback!

Just copy the .npmrc file from GITHUB_WORKSPACE to dest. Installation is performed by a pnpm version bundled with the action. It can read the .npmrc file.

That's so much more elegant, thank you for the suggestion!
Updated.