deploy supervisor image via server ide config

[akosyakov]

We should move configuration of the supervisor image to the IDE service in Gitpod Server.

[csweichel]

We need to make this change backwards compatible, i.e. an old server (which does not send the supervisor image ref) needs to work with a new workspace cluster (which might expect the supervisor image ref). To do that, we could just overwrite the static layer we currently add by changing the order of the layer sources in registry facade:

	var layerSources []LayerSource

        // add static layer first, so that they can be overwritten by the layers that come afterwards

	log.Info("preparing static layer")
	staticLayer := NewRevisioningLayerSource(CompositeLayerSource{})
	layerSources = append(layerSources, staticLayer)
	if len(cfg.StaticLayer) > 0 {
		l, err := buildStaticLayer(ctx, cfg.StaticLayer, newResolver)
		if err != nil {
			return nil, err
		}
		staticLayer.Update(l)
	}

	ideRefSource := func(s *api.ImageSpec) (ref string, err error) {
		return s.IdeRef, nil
	}
	ideLayerSource, err := NewSpecMappedImageSource(newResolver, ideRefSource)
	if err != nil {
		return nil, err
	}
	layerSources = append(layerSources, ideLayerSource)

	desktopIdeRefSource := func(s *api.ImageSpec) (ref string, err error) {
		return s.DesktopIdeRef, nil
	}
	desktopIdeLayerSource, err := NewSpecMappedImageSource(newResolver, desktopIdeRefSource)
	if err != nil {
		return nil, err
	}
	layerSources = append(layerSources, desktopIdeLayerSource)

	// introduce new supervisor layer source. It's ok if the ref returned is an empty string, the spec mapped
        // layer source handles this case gracefully.

	supervisorRefSource := func(s *api.ImageSpec) (ref string, err error) {
		return s.SupervisorRef, nil
	}
	supervisorLayerSource, err := NewSpecMappedImageSource(newResolver, supervisorRefSource)
	if err != nil {
		return nil, err
	}
	layerSources = append(layerSources, supervisorLayerSource)

	// content layer source needs to remain where it is and must not be overwritten by the spec mapped stuff

	clsrc, err := NewContentLayerSource()
	if err != nil {
		return nil, xerrors.Errorf("cannot create content layer source: %w", err)
	}
	layerSources = append(layerSources, clsrc)

[corneliusludmann]

/assign

[corneliusludmann]

One part of this issue is to add the supervisor ref to the ImageSpec of the registry facade. That's obvious.

But the supervisor image ref is also part of the ws-proxy config:

gitpod/chart/templates/ws-proxy-configmap.yaml

Line 50 in a30a1bf

"supervisorImage": "{{ template "gitpod.comp.imageFull" (dict "root" . "gp" $.Values "comp" .Values.components.workspace.supervisor) }}"

This seems to be used to handle supervisor frontend URLs via blobserve.

@csweichel How could we get this dynamic so that we can change the supervisor image in the server-ide-configmap only? Is it possible?

EDIT: I think we could get the supervisor image from the imageSpec annotation.