Remove edges from graph for deleted objects (#326)

Signed-off-by: Tamal Saha <[email protected]>

pkg/graph/graph.go

@@ -64,6 +64,20 @@ func (g *ObjectGraph) render(src kmapi.OID) (*runtime.RawExtension, error) {
 	}, nil
 }
 
+func (g *ObjectGraph) Delete(src kmapi.OID) {
+	g.m.Lock()
+	defer g.m.Unlock()
+
+	for lbl, connMap := range g.Edges[src] {
+		for to := range connMap {
+			g.delEdge(to, src, lbl)
+		}
+	}
+
+	delete(g.Edges, src)
+	delete(g.IDs, src)
+}
+
 func (g *ObjectGraph) Update(src kmapi.OID, connsPerLabel map[kmapi.EdgeLabel]ksets.OID) {
 	g.m.Lock()
 	defer g.m.Unlock()

pkg/graph/reconciler.go

@@ -49,7 +49,14 @@ func (r *Reconciler) Reconcile(ctx context.Context, req reconcile.Request) (reco
 	var obj unstructured.Unstructured
 	obj.SetGroupVersionKind(gvk)
 	if err := r.Get(context.TODO(), req.NamespacedName, &obj); err != nil {
-		log.Error(err, "unable to fetch", "group", r.R.Group, "kind", r.R.Kind)
+		oid := kmapi.ObjectID{
+			Group:     gvk.Group,
+			Kind:      gvk.Kind,
+			Namespace: req.Namespace,
+			Name:      req.Name,
+		}
+		objGraph.Delete(oid.OID())
+
 		// we'll ignore not-found errors, since they can't be fixed by an immediate
 		// requeue (we'll need to wait for a new notification), and we can get them
 		// on deleted requests.