Support multiple SSH keys for the same host

[imjasonh]

Before this change, if users provided two secrets annotated to target the same host, creds-init would fail to generate the ssh config.

This use case is entirely valid, to allow users to rotate keys for instance.

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Release Notes

Allow multiple SSH-auth secrets annotated for the same host

[tekton-robot]

The following is the coverage report on pkg/.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/credentials/gitcreds/ssh.go	87.7%	75.0%	-12.7

[ghost]

/lgtm

[vdemeester]

I am not sure this is gonna work, see my comment 👼

[vdemeester]

Does having multiple exact same Host works ? I read a bit man ssh_config and I am not sure it's documented (either works or not), but I have a fear it doesn't as it's gonna pick up the first one and if it fails, it will considered it failed.

I think it's possible to pass multiple IdentityFile though, like

Host github.com
    IdentityFile /etc/ssh/my_project_1_github_deploy_key
    IdentityFile /etc/ssh/my_project_2_github_deploy_key

[imjasonh]

I think you're right. Reading https://superuser.com/q/366649 it looks like the correct way to handle this is with multiple differently-named Hosts which each specify the same HostName

I've updated the PR to do this, where each Host includes the secret name to dedupe.

[imjasonh]

Seems I was wrong! Thanks e2e tests! :)

[vdemeester]

🤔

[tekton-robot]

The following is the coverage report on pkg/.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/credentials/gitcreds/ssh.go	87.7%	75.0%	-12.7

[tekton-robot]

The following is the coverage report on pkg/.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/credentials/gitcreds/ssh.go	87.7%	75.8%	-11.9

[vdemeester]

/lgtm

[tekton-robot]

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