Knative build should work natively on just docker

Expected Behavior

Knative build/build templates should work natively with just the docker engine as opposed to having a dependency on k8s. Given a source code repo, and a docker instance running, the process should be as simple as pointing the knative build/build template to the source code locally and it should give a docker image built locally out of source code. The image can later be pushed to any image registry as per the need.

Actual Behavior

Currently, we submit a YAML file to k8s that contains all the relevant details to finally end up with a running container on the same cluster.

Additional Info

@dgageot : Raising this issue as per our discussion on Twitter.

@vrock28 I didn't understand your issue was with knative/build. I thought it was mainly with Skaffold. I'm afraid unbinding knative build from Kubernetes won't happen. ping @mattmoor @ImJasonH

@dgageot : Apologies for the delayed response. I was under the impression that we were talking about knative build and not with Skaffold. Having said that, from a customer standpoint, the main ask here was to have a tool (like knative build) used on any OCI compliant container scheduler (docker etc) and the not have the dependency on the k8s cluster in itself to be available just to have an image built from source code. I also did have a conversation about this with @mattmoor and he was of the opinion that provisioning a user via RBAC policies on K8s cluster is much easier compared to daemons (docker and the likes) running as root on developer workstations (which i kind of dis-agree to :) ).

Also from a Image Assurance Policy standpoint, it would be good to allow the customers have relevant pipelines in place that gives them the ability to scan the images before being deployed on the k8s cluster (even on a pre-production cluster where developers are still pushing their code via knative build)