feat: Added multi-platform plugin hook support

[stevehipwell]

What this PR does / why we need it:

This PR addresses #7117 to allow plugin installation on Windows in a backwards compatible way. It also adds better OS specific hook support and improved platform command logic to support args containing a space.

Special notes for your reviewer:

Is there guidance for updating the documentation as AFAIK it's in a separate repo?

• Closes Windows support for Helm plugin installers #7117

If applicable:

• this PR contains documentation
• this PR contains unit tests
• this PR has been tested for backwards compatibility

[stevehipwell]

@sabre1041 could you or one of the other maintainers please take a look at this?

[sabre1041]

@sabre1041 could you or one of the other maintainers please take a look at this?

I've started to take a look. Will add some further thoughts in the next day or so

[stevehipwell]

@sabre1041 have you been able to find any time to look at this? And if so is there any feedback?

[sabre1041]

@sabre1041 have you been able to find any time to look at this? And if so is there any feedback?

getting back up to speed after a work conference. will review this week

[sabre1041]

Verified in Linux/OSX environments. Will try to find a Windows box to test against this week

[sabre1041]

@stevehipwell Receiving the following error on windows when installing a plugin:

helm plugin install https://github.com/databus23/helm-diff
/usr/bin/bash: C:Users<USERNAME>AppDataRoaminghelmpluginshelm-diff/install-binary.sh: No such file or directory
Error: plugin install hook for "diff" exited with error

Not receiving the same error with the latest helm release

[stevehipwell]

@sabre1041 the error should be consistent, but not necessarily identical, to the existing behaviour on Windows. Basically no currently published Helm plugins can support Windows (unless they have no hooks) so the install script should still fail with the new code.

[sabre1041]

@sabre1041 the error should be consistent, but not necessarily identical, to the existing behaviour on Windows. Basically no currently published Helm plugins can support Windows (unless they have no hooks) so the install script should still fail with the new code.

Contents of PR causes an error while the released code completes successfully. Tested using the helm diff plugin

[stevehipwell]

@sabre1041 I'm getting the exact same error for both the published code and the code on this branch using my Windows machine.

helm plugin install https://github.com/databus23/helm-diff
Error: exec: "sh": executable file not found in %PATH%

Has the Windows machine you're currently testing on been configured to support sh and do you have a custom value for HELM_PLUGIN_DIR set in this non-Windows shell? If so the difference could be caused by the early evaluation of the environment variables in the new version, which matches the way the platform command functions. I could short circuit the behaviour so that the legacy behaviour stays consistent.

[stevehipwell]

@sabre1041 this should now keep the current behaviour on Windows machines which can run sh commands.