metrics: Add basic API, agent and ova metrics

Metrics for api, agent and ova are implemented.
For API (agent and api_server) a middleware for chi router is used
giving basic metrics.
Agent: count the agents by status
OVA: count the downloads by status (failed or success)

Basic grafana dashboard is added.

Signed-off-by: Cosmin Tupangiu <[email protected]>

Makefile

@@ -141,6 +141,12 @@ deploy-on-openshift:
 	oc create secret generic migration-planner-secret -n ${MIGRATION_PLANNER_NAMESPACE} --from-literal=config_server=http://$$config_server --from-literal=config_server_ui=https://$$config_server_ui/migrate/wizard || true
 	ls deploy/k8s | awk '! /secret|service|template/' | xargs -I {} oc apply -n ${MIGRATION_PLANNER_NAMESPACE} -f deploy/k8s/{}
 
+deploy-local-obs:
+	@podman play kube --network host deploy/observability.yml
+
+undeploy-local-obs:
+	@podman kube down deploy/observability.yml
+
 undeploy-on-openshift:
 	oc delete route planner || true
 	oc delete route planner-agent || true

cmd/planner-api/run.go

@@ -96,6 +96,18 @@ var runCmd = &cobra.Command{
 			}
 		}()
 
+		go func() {
+			defer cancel()
+			listener, err := newListener("0.0.0.0:8080")
+			if err != nil {
+				zap.S().Named("metrics_server").Fatalf("creating listener: %s", err)
+			}
+			metricsServer := apiserver.NewMetricServer("0.0.0.0:8080", listener)
+			if err := metricsServer.Run(ctx); err != nil {
+				zap.S().Named("metrics_server").Fatalf("failed to run metrics server: %s", err)
+			}
+		}()
+
 		<-ctx.Done()
 		_ = ep.Close()