feat: add support to run kubedock at workspace startup

[l0rd]

This PR partially addresses eclipse-che/che#20227.

Using kubedock to run containers and local podman to build containers

The approach of this PR is to add kubedock in the universal developer image (Eclipse Che default image) and start it automatically if the env variable KUBEDOCK_ENABLED is set to true (can be set using a devfile).

When KUBEDOCK_ENABLED=true then the following commands will be executed with kubedock (the remaining commands, in particular podman build, will be executed by the local podman):

podman run
podman ps
podman exec
podman cp
podman logs
podman inspect
podman kill
podman rm
podman wait
podman stop
podman start

The limits of this approach

The kubedock approach allows to run containers from a container running on Kubernetes but has a few limits:

• podman build -t <image> . && podman run <image> doesn't work and should be replaced with podman build -t <image> . && podman push <image> && podman run <image>. That's because kubedock runs the container as a Kubernetes pod and, as a result, the kubelet on the node will try to pull <image> and will fail if it cannot find it.
• Clients that use the podman or docker API need to be configured to point to kubedock setting CONTAINER_HOST=tcp://127.0.0.1:2475 or DOCKER_HOST=tcp://127.0.0.1:2475 when they run containers and configured to point to local podman when building the container (something impracticable in some cases).
• Some podman comands such as generate kube are not supported yet
• If the option --env is provided then the command podman run fails

How to test

I have pushed this image to quay.io/mloriedo/universal-developer-image:kubedock-wrapper.

The PR can be tested on sandbox using the repo https://github.com/l0rd/dockerfile-hello-world:

• with kubedock support disabled (to check that podman build works as before)
• with kubedock support enabled (to check that podman build/push/run works)

[svor]

LGTM

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: ibuziuk, l0rd, svor

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[openshift-ci]

New changes are detected. LGTM label has been removed.

[deerskindoll]

eclipse-che/che-docs#2710