Add CanaryDeployment kind

- bootstrap the deployments. services and Istio virtual service
- use google/go-cmp to detect changes in the deployment pod spec

cmd/flagger/main.go

@@ -5,6 +5,8 @@ import (
 	"log"
 	"time"
 
+	"github.com/stefanprodan/flagger/pkg/operator"
+
 	_ "github.com/istio/glog"
 	sharedclientset "github.com/knative/pkg/client/clientset/versioned"
 	"github.com/knative/pkg/signals"
@@ -71,6 +73,7 @@ func main() {
 
 	rolloutInformerFactory := informers.NewSharedInformerFactory(rolloutClient, time.Second*30)
 	rolloutInformer := rolloutInformerFactory.Flagger().V1beta1().Canaries()
+	canaryDeploymentInformer := rolloutInformerFactory.Flagger().V1beta1().CanaryDeployments()
 
 	logger.Infof("Starting flagger version %s revision %s", version.VERSION, version.REVISION)
 
@@ -101,11 +104,22 @@ func main() {
 		logger,
 	)
 
+	cd := operator.NewController(
+		kubeClient,
+		sharedClient,
+		rolloutClient,
+		canaryDeploymentInformer,
+		controlLoopInterval,
+		metricsServer,
+		logger,
+	)
+
 	rolloutInformerFactory.Start(stopCh)
 
 	logger.Info("Waiting for informer caches to sync")
 	for _, synced := range []cache.InformerSynced{
 		rolloutInformer.Informer().HasSynced,
+		canaryDeploymentInformer.Informer().HasSynced,
 	} {
 		if ok := cache.WaitForCacheSync(stopCh, synced); !ok {
 			logger.Fatalf("Failed to wait for cache sync")
@@ -119,5 +133,12 @@ func main() {
 		}
 	}(c)
 
+	// start controller
+	go func(ctrl *operator.Controller) {
+		if err := ctrl.Run(2, stopCh); err != nil {
+			logger.Fatalf("Error running controller: %v", err)
+		}
+	}(cd)
+
 	<-stopCh
 }