feat: recurse submodules

[caarlos0]

Description

I think it's safe to assume that most people will want their submodules to be cloned as well. This adds that option to our go-git cloning.

Something I'm not sure about is how to test it. Should we create a phony git repo somewhere with submodules so we can add tests here?

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• Includes unit tests
• Adds integration tests if needed.

Reviewer Notes

• The code flow looks good.
• Unit tests and or integration tests added.

Release Notes

- kaniko now clone git repositories recursing submodules by default

[aca]

Faced the same issue.

Tried it but having authentication issue.
When kaniko context is set like this It fails to clone submodules
git://{token}@github.mycompany.com/org/repo.git#refs/heads/master

Do you have any clue for this?

[aca]

Faced the same issue.

Tried it but having authentication issue.
When kaniko context is set like this It fails to clone submodules
git://{token}@github.mycompany.com/org/repo.git#refs/heads/master

Do you have any clue for this?

If anyone face the same issue.
Try using GIT_USERNAME instead of adding token in context.
Clone options in kaniko should be fixed...

Still, only submodules with http protocol would work, https://