Implementation of multi-arch support for extension packages

[pacostas]

Summary

This implementation is based on the RFC https://github.com/buildpacks/rfcs/blob/main/text/0128-multiarch-builders-and-package.md

This PR allows the pack extension package to generate multi-platform OCI images and create an image index to combine them.

It also adds the --path flag to point to a directory on the extension that needs to be packaged.

This PR has not been tested in packaging a builder with multi-platform extension.

Output

Before

• We were not able to create multi-platform extensions
• We were not able to point to the directory of the extension

After

• Can generate multi-platform OCI images by using the --target flag
• Can specify the path of where the extension is located, using the --path flag.

Documentation

• Should this change be documented?
  • Yes
  • No

Related

Resolves #2183
Resolves #2160

[jjbustamante]

@pacostas Thank you so much for this work!!! I will review it tomorrow!!!

[pacostas]

You are welcome, feel free to make any suggestions! :)

[pacostas]

@jjbustamante Hello! With respect to your time, did you have the chance to take a look on the implementation?

[jjbustamante]

@jjbustamante Hello! With respect to your time, did you have the chance to take a look on the implementation?

@pacostas I am so sorry I haven't reviewed your PR, I will be pulling it and testing it locally, also, we are evaluating the current state of Kaniko because we are not sure how it will affect us. We use Kaniko for our extension implementation.

[pacostas]

Thank you very much :)

Thank you for the information about kaniko, do you know if kaniko is used somewhere else except extension and if there is a discussion/thread about that issue (to be in the loop)?

[jjbustamante]

Thank you very much :)

Thank you for the information about kaniko, do you know if kaniko is used somewhere else except extension and if there is a discussion/thread about that issue (to be in the loop)?

We only use Kaniko for extensions, we discussed it during our Working Group meeting on December 12th, but the recording is not on Youtube 😞

[jjbustamante]

Hi @pacostas
Thanks for working on this! I apologize for the late review, the PR is fine, I added a few nits.

One doubt, do you also want to add support for extensions added to a builder?

[pacostas]

Thank you for your review :)

One doubt, do you also want to add support for extensions added to a builder?

good point :) I havent tested it with a builder, as there are a lot of moving parts on the multi-arch side. Do you think we could leave it for now? And I can follow with another PR once things have settled.

[pacostas]

One test that is failing, I think is not related to this PR. By re-running, I think it will pass.

[jjbustamante]

One test that is failing, I think is not related to this PR. By re-running, I think it will pass.

Yeah, I need to prune some networks in our windows runner to fix it

[natalieparellano]

Yeah, I need to prune some networks in our windows runner to fix it

I thought I fixed this! So sad

[jjbustamante]

@pacostas Thanks for doing the change, the only reason stopping me from merging the change is just because I want to give it a try before merging it! The PR is ready to be merged.

@natalieparellano I am not sure if you have the time, but I thought that maybe we could update the samples repo with the multi-arch version for the extension and test them with this branch. Is it something you can help me? updating the samples repo with multi-arch extensions?

[pacostas]

@jjbustamante no rush, thank you very much :) BTW I have tested it with this extension.toml, https://github.com/paketo-buildpacks/ubi-nodejs-extension/pull/273/files#diff-21e42dd2276e594017780607a13f07b058d020447a73c11f032c77823a8ed493 I hope the code is useful for testing it with the samples too.

[natalieparellano]

Is it something you can help me? updating the samples repo with multi-arch extensions?

Sure!