[k8s plugin] Kubernetes:Run command should work w/o Docker

[azatsarynnyy]

The Kubernetes Tooling Che Plugin provides Kubernetes: Run command that does the following steps:

• builds a project image with docker build
• pushes the built image to an image registry with docker push
• creates a K8s deployment to run a pod with a container from the built image with kubectl run

Previously, the user should log into an image registry with docker login.

Since we can't use Docker daemon in a plugin sidecar, the goal of this task is to replace using Docker by the K8s Plugin with some rootless image build tool, e.g. Buildah.

[azatsarynnyy]

I've experimented with Buildah here by wrapping its calls into docker.sh script placed under /usr/local/bin to make it accessible from $PATH.
So the K8s Plugin still calls docker but the script calls the corresponded buildah commands.

[azatsarynnyy]

buildah login command has been added in the latest version - 1.8.2. But it's not available yet in CentOS (parent image for the K8s Plugin) app repos.
Likely, it will be published after the summit containers/buildah#1557 (comment)
I'll try with the containerized Buildah from https://quay.io/buildah/upstream

[gorkem]

@azatsarynnyy Can we change the extension itself to use buildah commands instead of the wrapper? I can discuss it with the extension owner if you think you can provide a PR for it. Perhaps, a preference or auto-detect mechanism to use buildah can be added?

[azatsarynnyy]

@gorkem it shouldn't take much time to add support for buildah as an alternative image builder in the VS Code K8s extension. So, if guys are interested in such a contribution, I can provide PR.

[gorkem]

@azatsarynnyy Can you provide a PR to upstream and ping me. Perhaps something that detects if buildah exists or docker not working and opts to the other.

[azatsarynnyy]

@gorkem ok, I'll tackle it next week

[azatsarynnyy]

Reopening it to work on adding Buildah support to VS Code Kubernetes Tools extension upstream project.

[azatsarynnyy]

Buildah support has been added to VS Code Kubernetes extension vscode-kubernetes-tools/vscode-kubernetes-tools#559

It's included to the recently published v1.0.1

The next steps are:

• add a new version of the Kubernetes Tooling Che Plugin based on the VS Code Kubernetes Tool v1.0.1
• get rid of the wrapper script in the plugin Dockerfile
• update the plugin's README file with the info how to switch image build tool from Docker to Buildah

[azatsarynnyy]

depends on #13702

[azatsarynnyy]

Fixed for K8s in eclipse-che/che-theia#510
For OpenShift, will be a separate issue if needed.