Add support for gentoo templates and cloud.cfg

[vteratipally]

Add support for gentoo in cloud.cfg and templates

Add support for gentoo in cloud.cfg and templates.
This is an already existing patch in gentoo upstream https://gitweb.gentoo.org/repo/gentoo.git/tree/app-emulation/cloud-init/files/cloud-init-20.4-gentoo-support-upstream-templates.patch.
Cherry-picking the patch to the upstream cloud-init.

Additional Context

Test Steps

Checklist:

• My code follows the process laid out in the documentation
• I have updated or added any unit tests accordingly
• I have updated or added any documentation accordingly

[holmanb]

Hi @vteratipally, thanks for the PR. A while ago somebody tried to get something similar merged, but it never landed. I think this is a welcome contribution, but tests don't currently pass. Once tests are passing I can add a review.

I did notice that the cloud-init ebuild in the gentoo repo seems to have duplicate patches listed, which makes me wonder if the gentoo patches even work. Additional context would be helpful. Would you happen to know a) if this package builds cleanly with emerge and b) where/how this package gets used? This information will help with testing.

[vteratipally]

Yes the gentoo ebuild with the patches works fine. For example, it is used extensively here https://cos.googlesource.com/cos/overlays/board-overlays/+/refs/heads/master/project-lakitu/app-emulation/cloud-init/ for building the cloud-init package into the Container Optimized OS.

[holmanb]

Thanks for the feedback @vteratipally. This does require a small change, but otherwise I think it's probably good.

[TheRealFalcon]

@holmanb , this look good to you now? If so, I can merge it.

[holmanb]

@TheRealFalcon - Yep, looks good to me!

[TheRealFalcon]

Thanks!