[FEATURE]: enable using other building engines (img, buildah, etc.)

[squillace]

For comment.

[bacongobbler]

I think this ticket's requests are being covered in https://github.com/Azure/draft/issues/700. Basically we need to break out the container builder infra into separate "drivers" which can then be installed via draft plugin install. Once that's done, we can write up documentation to demonstrate how users can create and use other container builders with Draft.

Is there something else missing from that ticket that we need to track separately here, or should we go ahead and close this as a duplicate? :)

[AkihiroSuda]

WDYT about using CBI (a vendor-neutral interface for building images on a Kubernetes cluster)?
https://github.com/containerbuilding/cbi

The following plugins are implemented so far:

Plugin	Backend	Dockerfile	cloudbuild.yaml	OpenShift S2I	BuildKit LLB
docker	Docker	Yes ✅
buildkit	BuildKit	Yes ✅			Planned
buildah	Buildah	Yes ✅
kaniko	kaniko	Yes ✅
img	img	Yes ✅
gcb	Google Cloud Container Builder	Yes ✅	Yes ✅
s2i	OpenShift Source-to-Image (S2I)			Yes ✅

Discussion in Skaffold community: GoogleContainerTools/skaffold#596

[bacongobbler]

closing as a duplicate of #700 so we can track one ticket

@AkihiroSuda can CBI run builds locally as well? A pluggable interface sounds nice, but at the same time we have users (me) who wants to use their local container builders to do the build and push steps as their machines are vastly quicker for processing power than what's available in the cloud. That said I wouldn't be opposed to allowing someone to add support for CBI once we have the infra in place to support image builder drivers. Might be a good discussion point to carry on in #700.