On-cluster build: Implement --git flag for func deploy

[omerbensaadon]

• If the user uses func deploy --git <GIT_REPO>
  • the func.yaml will automatically set build to git and specify the git repository

In other words, I will be defaulting the following information to avoid manually editing func.yaml:

build: git                                          # required, specify `git` build type
git:
  url: https://github.com/my-repo/my-function.git   # required, git repository with the function source code
  revision: main                                    # optional, git revision to be used (branch, tag, commit)
  # contextDir: myfunction                          # optional, needed only if the function is not located
                                                    # in the repository root folder

I will update this issue if I find more details and consequences of using --git

[salaboy]

@omerbensaadon did you created this one for me? @omerbensaadon do you know what kind of permissions do I need to be able to create issues like this from the check list?

[omerbensaadon]

I think it's just OWNERS? I'm still an owner on knative-sandbox so the feature shows up for me

[salaboy]

Looking at this comment in functions_buildtype.go:

	BuildTypeGit      = "git"
	//BuildTypeRemote   = "remote"	// TODO not supported yet

It seems that we are using BuildType git for remote builds.. which I think is fine.. so to avoid confusion I think that removing BuildTypeRemote comment will make sense..

Is there any other way to do a git build without being remote? Is there a local remote git build? meaning that a git repo is cloned locally and built?
Does it make sense to implement as part of this issue something like:

func deploy --build remote --git <GIT_REPO>

??
This goes against the guide: https://github.com/knative-sandbox/kn-plugin-func/blob/main/docs/guides/on-cluster-build.md where the build type git is used.

@zroubalik any comments?

[zroubalik]

@salaboy the idea is to use git type for the current git based workflow and remote for the approach, where on cluster build is being executed from the source code directly uploaded to the cluster (ie. without git), ie. usecase 2 from https://docs.google.com/document/d/1iQFVtfsrYb4pp616h3B_IXQB1Cck1oxt7ypZyU8ChzE/edit#heading=h.pvswm4g8giw9

[pseudorandoom]

I see we are using --build and --git but we still need to specify the git revision (branch) too. Is that going to be a new flag for the command or is there another way it should be specified? @zroubalik @salaboy

[zroubalik]

https://docs.google.com/document/d/1iQFVtfsrYb4pp616h3B_IXQB1Cck1oxt7ypZyU8ChzE/edit#heading=h.y2uopsqzp10k

As proposed there ^, it could be: --git-url=https://github.com/zroubalik/test-function.git#mybranch or it could be --git-url=https://github.com/zroubalik/test-function.git --git-branch=mybranch or maybe both? 🤷‍♂️