Async PV for workspace: server pod (in user namespace) to provide access to PVC

[benoitf]

Introduce new pod to serve files to user workspaces

subtask of #15384

The pod should boot first without PVC at first to serve requests as fast as possible and do not block requests if new workspace (no persistent data)

impl note:

for obvious reason, do not keep list of managed workspaces into a PVC (as we need to reply as soon as possible if there is no persistent data for a given workspace)
--> config-map
--> deployment / annotation
--> custom resource

configuration/enhancements

• allow shutdown after idle
• allow to wake up when user access to the dashboard

investigate how this pod could wake up on demand

automatic / wake up scale to zero knative

[ibuziuk]

@benoitf in user namespace = in the namespace where workspaces are created, right?

[benoitf]

@ibuziuk yes