Add mirror to router interface and implement for istio router

The mirror option will be used to tell routers to configure traffic
mirroring.  Implement mirror for GetRoutes and SetRoutes for Istio.  For
other routers, GetRoutes always returns mirror == false, and SetRoutes
ignores mirror.

After this change there is no behavior change because no code sets
mirror true (yet).

Enhanced TestIstioRouter_SetRoutes and TestIstioRouter_GetRoutes.

pkg/controller/scheduler.go

@@ -155,7 +155,7 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 
 	// check if virtual service exists
 	// and if it contains weighted destination routes to the primary and canary services
-	primaryWeight, canaryWeight, err := meshRouter.GetRoutes(cd)
+	primaryWeight, canaryWeight, mirrored, err := meshRouter.GetRoutes(cd)
 	if err != nil {
 		c.recordEventWarningf(cd, "%v", err)
 		return
@@ -176,7 +176,7 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 		// route all traffic back to primary
 		primaryWeight = 100
 		canaryWeight = 0
-		if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight); err != nil {
+		if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight, false); err != nil {
 			c.recordEventWarningf(cd, "%v", err)
 			return
 		}
@@ -218,7 +218,7 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 	if cd.Status.Phase == flaggerv1.CanaryPhasePromoting {
 		if provider != "kubernetes" {
 			c.recordEventInfof(cd, "Routing all traffic to primary")
-			if err := meshRouter.SetRoutes(cd, 100, 0); err != nil {
+			if err := meshRouter.SetRoutes(cd, 100, 0, false); err != nil {
 				c.recordEventWarningf(cd, "%v", err)
 				return
 			}
@@ -275,7 +275,7 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 		// route all traffic back to primary
 		primaryWeight = 100
 		canaryWeight = 0
-		if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight); err != nil {
+		if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight, false); err != nil {
 			c.recordEventWarningf(cd, "%v", err)
 			return
 		}
@@ -328,7 +328,7 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 	if len(cd.Spec.CanaryAnalysis.Match) > 0 && cd.Spec.CanaryAnalysis.Iterations > 0 {
 		// route traffic to canary and increment iterations
 		if cd.Spec.CanaryAnalysis.Iterations > cd.Status.Iterations {
-			if err := meshRouter.SetRoutes(cd, 0, 100); err != nil {
+			if err := meshRouter.SetRoutes(cd, 0, 100, false); err != nil {
 				c.recordEventWarningf(cd, "%v", err)
 				return
 			}
@@ -390,7 +390,7 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 		if cd.Spec.CanaryAnalysis.Iterations == cd.Status.Iterations {
 			if provider != "kubernetes" {
 				c.recordEventInfof(cd, "Routing all traffic to canary")
-				if err := meshRouter.SetRoutes(cd, 0, 100); err != nil {
+				if err := meshRouter.SetRoutes(cd, 0, 100, false); err != nil {
 					c.recordEventWarningf(cd, "%v", err)
 					return
 				}
@@ -489,7 +489,7 @@ func (c *Controller) shouldSkipAnalysis(cd *flaggerv1.Canary, meshRouter router.
 	// route all traffic to primary
 	primaryWeight = 100
 	canaryWeight = 0
-	if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight); err != nil {
+	if err := meshRouter.SetRoutes(cd, primaryWeight, canaryWeight, false); err != nil {
 		c.recordEventWarningf(cd, "%v", err)
 		return false
 	}

pkg/controller/scheduler_test.go

@@ -123,7 +123,7 @@ func TestScheduler_NewRevisionReset(t *testing.T) {
 	// advance
 	mocks.ctrl.advanceCanary("podinfo", "default", true)
 
-	primaryWeight, canaryWeight, err := mocks.router.GetRoutes(mocks.canary)
+	primaryWeight, canaryWeight, mirrored, err := mocks.router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -136,6 +136,10 @@ func TestScheduler_NewRevisionReset(t *testing.T) {
 		t.Errorf("Got canary route %v wanted %v", canaryWeight, 10)
 	}
 
+	if mirrored != false {
+		t.Errorf("Got mirrored %v wanted %v", mirrored, false)
+	}
+
 	// second update
 	dep2.Spec.Template.Spec.ServiceAccountName = "test"
 	_, err = mocks.kubeClient.AppsV1().Deployments("default").Update(dep2)
@@ -146,7 +150,7 @@ func TestScheduler_NewRevisionReset(t *testing.T) {
 	// detect changes
 	mocks.ctrl.advanceCanary("podinfo", "default", true)
 
-	primaryWeight, canaryWeight, err = mocks.router.GetRoutes(mocks.canary)
+	primaryWeight, canaryWeight, mirrored, err = mocks.router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -158,6 +162,10 @@ func TestScheduler_NewRevisionReset(t *testing.T) {
 	if canaryWeight != 0 {
 		t.Errorf("Got canary route %v wanted %v", canaryWeight, 0)
 	}
+
+	if mirrored != false {
+		t.Errorf("Got mirrored %v wanted %v", mirrored, false)
+	}
 }
 
 func TestScheduler_Promotion(t *testing.T) {
@@ -201,14 +209,14 @@ func TestScheduler_Promotion(t *testing.T) {
 	// detect configs changes
 	mocks.ctrl.advanceCanary("podinfo", "default", true)
 
-	primaryWeight, canaryWeight, err := mocks.router.GetRoutes(mocks.canary)
+	primaryWeight, canaryWeight, mirrored, err := mocks.router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
 
 	primaryWeight = 60
 	canaryWeight = 40
-	err = mocks.router.SetRoutes(mocks.canary, primaryWeight, canaryWeight)
+	err = mocks.router.SetRoutes(mocks.canary, primaryWeight, canaryWeight, mirrored)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -242,7 +250,7 @@ func TestScheduler_Promotion(t *testing.T) {
 	// finalise
 	mocks.ctrl.advanceCanary("podinfo", "default", true)
 
-	primaryWeight, canaryWeight, err = mocks.router.GetRoutes(mocks.canary)
+	primaryWeight, canaryWeight, mirrored, err = mocks.router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -255,6 +263,10 @@ func TestScheduler_Promotion(t *testing.T) {
 		t.Errorf("Got canary route %v wanted %v", canaryWeight, 0)
 	}
 
+	if mirrored != false {
+		t.Errorf("Got mirrored %v wanted %v", mirrored, false)
+	}
+
 	primaryDep, err := mocks.kubeClient.AppsV1().Deployments("default").Get("podinfo-primary", metav1.GetOptions{})
 	if err != nil {
 		t.Fatal(err.Error())
@@ -326,7 +338,7 @@ func TestScheduler_ABTesting(t *testing.T) {
 	mocks.ctrl.advanceCanary("podinfo", "default", true)
 
 	// check if traffic is routed to canary
-	primaryWeight, canaryWeight, err := mocks.router.GetRoutes(mocks.canary)
+	primaryWeight, canaryWeight, mirrored, err := mocks.router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -339,6 +351,10 @@ func TestScheduler_ABTesting(t *testing.T) {
 		t.Errorf("Got canary route %v wanted %v", canaryWeight, 100)
 	}
 
+	if mirrored != false {
+		t.Errorf("Got mirrored %v wanted %v", mirrored, false)
+	}
+
 	cd, err := mocks.flaggerClient.FlaggerV1alpha3().Canaries("default").Get("podinfo", metav1.GetOptions{})
 	if err != nil {
 		t.Fatal(err.Error())

pkg/router/appmesh.go

@@ -252,6 +252,7 @@ func (ar *AppMeshRouter) reconcileVirtualService(canary *flaggerv1.Canary, name
 func (ar *AppMeshRouter) GetRoutes(canary *flaggerv1.Canary) (
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 	err error,
 ) {
 	targetName := canary.Spec.TargetRef.Name
@@ -286,6 +287,8 @@ func (ar *AppMeshRouter) GetRoutes(canary *flaggerv1.Canary) (
 			vsName, targetName, targetName)
 	}
 
+	mirrored = false
+
 	return
 }
 
@@ -294,6 +297,7 @@ func (ar *AppMeshRouter) SetRoutes(
 	canary *flaggerv1.Canary,
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 ) error {
 	targetName := canary.Spec.TargetRef.Name
 	vsName := fmt.Sprintf("%s.%s", targetName, canary.Namespace)

pkg/router/appmesh_test.go

@@ -144,12 +144,12 @@ func TestAppmeshRouter_GetSetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
-	err = router.SetRoutes(mocks.appmeshCanary, 60, 40)
+	err = router.SetRoutes(mocks.appmeshCanary, 60, 40, false)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
 
-	p, c, err := router.GetRoutes(mocks.appmeshCanary)
+	p, c, m, err := router.GetRoutes(mocks.appmeshCanary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -161,4 +161,8 @@ func TestAppmeshRouter_GetSetRoutes(t *testing.T) {
 	if c != 40 {
 		t.Errorf("Got canary weight %v wanted %v", c, 40)
 	}
+
+	if m != false {
+		t.Errorf("Got mirror %v wanted %v", m, false)
+	}
 }

pkg/router/gloo.go

@@ -63,11 +63,11 @@ func NewGlooRouterWithClient(ctx context.Context, routingRuleClient gloov1.Upstr
 // Reconcile creates or updates the Istio virtual service
 func (gr *GlooRouter) Reconcile(canary *flaggerv1.Canary) error {
 	// do we have routes already?
-	if _, _, err := gr.GetRoutes(canary); err == nil {
+	if _, _, _, err := gr.GetRoutes(canary); err == nil {
 		// we have routes, no need to do anything else
 		return nil
 	} else if solokiterror.IsNotExist(err) {
-		return gr.SetRoutes(canary, 100, 0)
+		return gr.SetRoutes(canary, 100, 0, false)
 	} else {
 		return err
 	}
@@ -77,6 +77,7 @@ func (gr *GlooRouter) Reconcile(canary *flaggerv1.Canary) error {
 func (gr *GlooRouter) GetRoutes(canary *flaggerv1.Canary) (
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 	err error,
 ) {
 	targetName := canary.Spec.TargetRef.Name
@@ -101,6 +102,8 @@ func (gr *GlooRouter) GetRoutes(canary *flaggerv1.Canary) (
 			targetName, canary.Namespace, targetName, targetName)
 	}
 
+	mirrored = false
+
 	return
 }
 
@@ -109,6 +112,7 @@ func (gr *GlooRouter) SetRoutes(
 	canary *flaggerv1.Canary,
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 ) error {
 	targetName := canary.Spec.TargetRef.Name
 

pkg/router/gloo_test.go

@@ -68,15 +68,16 @@ func TestGlooRouter_SetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
-	p, c, err := router.GetRoutes(mocks.canary)
+	p, c, m, err := router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
 
 	p = 50
 	c = 50
+	m = false
 
-	err = router.SetRoutes(mocks.canary, p, c)
+	err = router.SetRoutes(mocks.canary, p, c, m)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -127,7 +128,7 @@ func TestGlooRouter_GetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
-	p, c, err := router.GetRoutes(mocks.canary)
+	p, c, m, err := router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -139,4 +140,8 @@ func TestGlooRouter_GetRoutes(t *testing.T) {
 	if c != 0 {
 		t.Errorf("Got canary weight %v wanted %v", c, 0)
 	}
+
+	if m != false {
+		t.Errorf("Got mirror %v wanted %v", m, false)
+	}
 }

pkg/router/ingress.go

@@ -106,19 +106,20 @@ func (i *IngressRouter) Reconcile(canary *flaggerv1.Canary) error {
 func (i *IngressRouter) GetRoutes(canary *flaggerv1.Canary) (
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 	err error,
 ) {
 	canaryIngressName := fmt.Sprintf("%s-canary", canary.Spec.IngressRef.Name)
 	canaryIngress, err := i.kubeClient.ExtensionsV1beta1().Ingresses(canary.Namespace).Get(canaryIngressName, metav1.GetOptions{})
 	if err != nil {
-		return 0, 0, err
+		return 0, 0, false, err
 	}
 
 	// A/B testing
 	if len(canary.Spec.CanaryAnalysis.Match) > 0 {
 		for k := range canaryIngress.Annotations {
 			if k == i.GetAnnotationWithPrefix("canary-by-cookie") || k == i.GetAnnotationWithPrefix("canary-by-header") {
-				return 0, 100, nil
+				return 0, 100, false, nil
 			}
 		}
 	}
@@ -128,7 +129,7 @@ func (i *IngressRouter) GetRoutes(canary *flaggerv1.Canary) (
 		if k == i.GetAnnotationWithPrefix("canary-weight") {
 			val, err := strconv.Atoi(v)
 			if err != nil {
-				return 0, 0, err
+				return 0, 0, false, err
 			}
 
 			canaryWeight = val
@@ -137,6 +138,7 @@ func (i *IngressRouter) GetRoutes(canary *flaggerv1.Canary) (
 	}
 
 	primaryWeight = 100 - canaryWeight
+	mirrored = false
 	return
 }
 
@@ -144,6 +146,7 @@ func (i *IngressRouter) SetRoutes(
 	canary *flaggerv1.Canary,
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 ) error {
 	canaryIngressName := fmt.Sprintf("%s-canary", canary.Spec.IngressRef.Name)
 	canaryIngress, err := i.kubeClient.ExtensionsV1beta1().Ingresses(canary.Namespace).Get(canaryIngressName, metav1.GetOptions{})

pkg/router/ingress_test.go

@@ -56,15 +56,16 @@ func TestIngressRouter_GetSetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
-	p, c, err := router.GetRoutes(mocks.ingressCanary)
+	p, c, m, err := router.GetRoutes(mocks.ingressCanary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
 
 	p = 50
 	c = 50
+	m = false
 
-	err = router.SetRoutes(mocks.ingressCanary, p, c)
+	err = router.SetRoutes(mocks.ingressCanary, p, c, m)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -93,8 +94,9 @@ func TestIngressRouter_GetSetRoutes(t *testing.T) {
 
 	p = 100
 	c = 0
+	m = false
 
-	err = router.SetRoutes(mocks.ingressCanary, p, c)
+	err = router.SetRoutes(mocks.ingressCanary, p, c, m)
 	if err != nil {
 		t.Fatal(err.Error())
 	}

pkg/router/istio.go

@@ -101,8 +101,6 @@ func (ir *IstioRouter) reconcileDestinationRule(canary *flaggerv1.Canary, name s
 
 func (ir *IstioRouter) reconcileVirtualService(canary *flaggerv1.Canary) error {
 	targetName := canary.Spec.TargetRef.Name
-	primaryName := fmt.Sprintf("%s-primary", targetName)
-	canaryName := fmt.Sprintf("%s-canary", targetName)
 
 	// set hosts and add the ClusterIP service host if it doesn't exists
 	hosts := canary.Spec.Service.Hosts
@@ -133,6 +131,8 @@ func (ir *IstioRouter) reconcileVirtualService(canary *flaggerv1.Canary) error {
 	}
 
 	// create destinations with primary weight 100% and canary weight 0%
+	primaryName := fmt.Sprintf("%s-primary", targetName)
+	canaryName := fmt.Sprintf("%s-canary", targetName)
 	canaryRoute := []istiov1alpha3.DestinationWeight{
 		makeDestination(canary, primaryName, 100),
 		makeDestination(canary, canaryName, 0),
@@ -210,9 +210,14 @@ func (ir *IstioRouter) reconcileVirtualService(canary *flaggerv1.Canary) error {
 		return fmt.Errorf("VirtualService %s.%s query error %v", targetName, canary.Namespace, err)
 	}
 
-	// update service but keep the original destination weights
+	// update service but keep the original destination weights and mirror
 	if virtualService != nil {
-		if diff := cmp.Diff(newSpec, virtualService.Spec, cmpopts.IgnoreFields(istiov1alpha3.DestinationWeight{}, "Weight")); diff != "" {
+		if diff := cmp.Diff(
+			newSpec,
+			virtualService.Spec,
+			cmpopts.IgnoreFields(istiov1alpha3.DestinationWeight{}, "Weight"),
+			cmpopts.IgnoreFields(istiov1alpha3.HTTPRoute{}, "Mirror"),
+		); diff != "" {
 			vtClone := virtualService.DeepCopy()
 			vtClone.Spec = newSpec
 
@@ -232,6 +237,7 @@ func (ir *IstioRouter) reconcileVirtualService(canary *flaggerv1.Canary) error {
 func (ir *IstioRouter) GetRoutes(canary *flaggerv1.Canary) (
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 	err error,
 ) {
 	targetName := canary.Spec.TargetRef.Name
@@ -264,6 +270,9 @@ func (ir *IstioRouter) GetRoutes(canary *flaggerv1.Canary) (
 			canaryWeight = route.Weight
 		}
 	}
+	if httpRoute.Mirror != nil && httpRoute.Mirror.Host != "" {
+		mirrored = true
+	}
 
 	if primaryWeight == 0 && canaryWeight == 0 {
 		err = fmt.Errorf("VirtualService %s.%s does not contain routes for %s-primary and %s-canary",
@@ -278,6 +287,7 @@ func (ir *IstioRouter) SetRoutes(
 	canary *flaggerv1.Canary,
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 ) error {
 	targetName := canary.Spec.TargetRef.Name
 	primaryName := fmt.Sprintf("%s-primary", targetName)
@@ -310,6 +320,12 @@ func (ir *IstioRouter) SetRoutes(
 		},
 	}
 
+	if mirrored {
+		vsCopy.Spec.Http[0].Mirror = &istiov1alpha3.Destination{
+			Host: canaryName,
+		}
+	}
+
 	// fix routing (A/B testing)
 	if len(canary.Spec.CanaryAnalysis.Match) > 0 {
 		// merge the common routes with the canary ones

pkg/router/istio_test.go

@@ -119,15 +119,16 @@ func TestIstioRouter_SetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
-	p, c, err := router.GetRoutes(mocks.canary)
+	p, c, m, err := router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
 
-	p = 50
-	c = 50
+	p = 60
+	c = 40
+	m = false
 
-	err = router.SetRoutes(mocks.canary, p, c)
+	err = router.SetRoutes(mocks.canary, p, c, m)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -137,16 +138,20 @@ func TestIstioRouter_SetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
+	pHost := fmt.Sprintf("%s-primary", mocks.canary.Spec.TargetRef.Name)
+	cHost := fmt.Sprintf("%s-canary", mocks.canary.Spec.TargetRef.Name)
 	pRoute := istiov1alpha3.DestinationWeight{}
 	cRoute := istiov1alpha3.DestinationWeight{}
+	var mirror *istiov1alpha3.Destination
 
 	for _, http := range vs.Spec.Http {
 		for _, route := range http.Route {
-			if route.Destination.Host == fmt.Sprintf("%s-primary", mocks.canary.Spec.TargetRef.Name) {
+			if route.Destination.Host == pHost {
 				pRoute = route
 			}
-			if route.Destination.Host == fmt.Sprintf("%s-canary", mocks.canary.Spec.TargetRef.Name) {
+			if route.Destination.Host == cHost {
 				cRoute = route
+				mirror = http.Mirror
 			}
 		}
 	}
@@ -158,6 +163,51 @@ func TestIstioRouter_SetRoutes(t *testing.T) {
 	if cRoute.Weight != c {
 		t.Errorf("Got canary weight %v wanted %v", cRoute.Weight, c)
 	}
+
+	if mirror != nil {
+		t.Errorf("Got mirror %v wanted nil", mirror)
+	}
+
+	mirror = nil
+	p = 100
+	c = 0
+	m = true
+
+	err = router.SetRoutes(mocks.canary, p, c, m)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	vs, err = mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get("podinfo", metav1.GetOptions{})
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	for _, http := range vs.Spec.Http {
+		for _, route := range http.Route {
+			if route.Destination.Host == pHost {
+				pRoute = route
+			}
+			if route.Destination.Host == cHost {
+				cRoute = route
+				mirror = http.Mirror
+			}
+		}
+	}
+
+	if pRoute.Weight != p {
+		t.Errorf("Got primary weight %v wanted %v", pRoute.Weight, p)
+	}
+
+	if cRoute.Weight != c {
+		t.Errorf("Got canary weight %v wanted %v", cRoute.Weight, c)
+	}
+
+	if mirror == nil {
+		t.Errorf("Got mirror nil wanted a mirror")
+	} else if mirror.Host != cHost {
+		t.Errorf("Got mirror host \"%v\" wanted \"%v\"", mirror.Host, cHost)
+	}
 }
 
 func TestIstioRouter_GetRoutes(t *testing.T) {
@@ -174,7 +224,7 @@ func TestIstioRouter_GetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
-	p, c, err := router.GetRoutes(mocks.canary)
+	p, c, m, err := router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -186,6 +236,74 @@ func TestIstioRouter_GetRoutes(t *testing.T) {
 	if c != 0 {
 		t.Errorf("Got canary weight %v wanted %v", c, 0)
 	}
+
+	if m != false {
+		t.Errorf("Got mirror %v wanted %v", m, false)
+	}
+
+	mocks.canary = newMockMirror()
+
+	err = router.Reconcile(mocks.canary)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	p, c, m, err = router.GetRoutes(mocks.canary)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	if p != 100 {
+		t.Errorf("Got primary weight %v wanted %v", p, 100)
+	}
+
+	if c != 0 {
+		t.Errorf("Got canary weight %v wanted %v", c, 0)
+	}
+
+	// A Canary resource with mirror on does not automatically create mirroring
+	// in the virtual server (mirroring is activated as a temporary stage).
+	if m != false {
+		t.Errorf("Got mirror %v wanted %v", m, false)
+	}
+
+	// Adjust vs to activate mirroring.
+	vs, err := mocks.meshClient.NetworkingV1alpha3().VirtualServices("default").Get("podinfo", metav1.GetOptions{})
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	cHost := fmt.Sprintf("%s-canary", mocks.canary.Spec.TargetRef.Name)
+	for i, http := range vs.Spec.Http {
+		for _, route := range http.Route {
+			if route.Destination.Host == cHost {
+				vs.Spec.Http[i].Mirror = &istiov1alpha3.Destination{
+					Host: cHost,
+				}
+			}
+		}
+	}
+	_, err = mocks.meshClient.NetworkingV1alpha3().VirtualServices(mocks.canary.Namespace).Update(vs)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	p, c, m, err = router.GetRoutes(mocks.canary)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	if p != 100 {
+		t.Errorf("Got primary weight %v wanted %v", p, 100)
+	}
+
+	if c != 0 {
+		t.Errorf("Got canary weight %v wanted %v", c, 0)
+	}
+
+	if m != true {
+		t.Errorf("Got mirror %v wanted %v", m, true)
+	}
 }
 
 func TestIstioRouter_HTTPRequestHeaders(t *testing.T) {
@@ -276,8 +394,9 @@ func TestIstioRouter_ABTest(t *testing.T) {
 
 	p := 0
 	c := 100
+	m := false
 
-	err = router.SetRoutes(mocks.abtest, p, c)
+	err = router.SetRoutes(mocks.abtest, p, c, m)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -287,16 +406,20 @@ func TestIstioRouter_ABTest(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
+	pHost := fmt.Sprintf("%s-primary", mocks.abtest.Spec.TargetRef.Name)
+	cHost := fmt.Sprintf("%s-canary", mocks.abtest.Spec.TargetRef.Name)
 	pRoute := istiov1alpha3.DestinationWeight{}
 	cRoute := istiov1alpha3.DestinationWeight{}
+	var mirror *istiov1alpha3.Destination
 
 	for _, http := range vs.Spec.Http {
 		for _, route := range http.Route {
-			if route.Destination.Host == fmt.Sprintf("%s-primary", mocks.abtest.Spec.TargetRef.Name) {
+			if route.Destination.Host == pHost {
 				pRoute = route
 			}
-			if route.Destination.Host == fmt.Sprintf("%s-canary", mocks.abtest.Spec.TargetRef.Name) {
+			if route.Destination.Host == cHost {
 				cRoute = route
+				mirror = http.Mirror
 			}
 		}
 	}
@@ -308,4 +431,8 @@ func TestIstioRouter_ABTest(t *testing.T) {
 	if cRoute.Weight != c {
 		t.Errorf("Got canary weight %v wanted %v", cRoute.Weight, c)
 	}
+
+	if mirror != nil {
+		t.Errorf("Got mirror %v wanted nil", mirror)
+	}
 }

pkg/router/nop.go

@@ -12,13 +12,13 @@ func (*NopRouter) Reconcile(canary *flaggerv1.Canary) error {
 	return nil
 }
 
-func (*NopRouter) SetRoutes(canary *flaggerv1.Canary, primaryWeight int, canaryWeight int) error {
+func (*NopRouter) SetRoutes(canary *flaggerv1.Canary, primaryWeight int, canaryWeight int, mirror bool) error {
 	return nil
 }
 
-func (*NopRouter) GetRoutes(canary *flaggerv1.Canary) (primaryWeight int, canaryWeight int, err error) {
+func (*NopRouter) GetRoutes(canary *flaggerv1.Canary) (primaryWeight int, canaryWeight int, mirror bool, err error) {
 	if canary.Status.Iterations > 0 {
-		return 0, 100, nil
+		return 0, 100, false, nil
 	}
-	return 100, 0, nil
+	return 100, 0, false, nil
 }

pkg/router/router.go

@@ -4,6 +4,6 @@ import flaggerv1 "github.com/weaveworks/flagger/pkg/apis/flagger/v1alpha3"
 
 type Interface interface {
 	Reconcile(canary *flaggerv1.Canary) error
-	SetRoutes(canary *flaggerv1.Canary, primaryWeight int, canaryWeight int) error
-	GetRoutes(canary *flaggerv1.Canary) (primaryWeight int, canaryWeight int, err error)
+	SetRoutes(canary *flaggerv1.Canary, primaryWeight int, canaryWeight int, mirrored bool) error
+	GetRoutes(canary *flaggerv1.Canary) (primaryWeight int, canaryWeight int, mirrored bool, err error)
 }

pkg/router/router_test.go

@@ -137,6 +137,12 @@ func newMockCanary() *v1alpha3.Canary {
 	return cd
 }
 
+func newMockMirror() *v1alpha3.Canary {
+	cd := newMockCanary()
+	cd.Spec.CanaryAnalysis.Mirror = true
+	return cd
+}
+
 func newMockABTest() *v1alpha3.Canary {
 	cd := &v1alpha3.Canary{
 		TypeMeta: metav1.TypeMeta{APIVersion: v1alpha3.SchemeGroupVersion.String()},

pkg/router/smi.go

@@ -107,6 +107,7 @@ func (sr *SmiRouter) Reconcile(canary *flaggerv1.Canary) error {
 func (sr *SmiRouter) GetRoutes(canary *flaggerv1.Canary) (
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 	err error,
 ) {
 	targetName := canary.Spec.TargetRef.Name
@@ -137,6 +138,8 @@ func (sr *SmiRouter) GetRoutes(canary *flaggerv1.Canary) (
 			targetName, canary.Namespace, primaryName, canaryName)
 	}
 
+	mirrored = false
+
 	return
 }
 
@@ -145,6 +148,7 @@ func (sr *SmiRouter) SetRoutes(
 	canary *flaggerv1.Canary,
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 ) error {
 	targetName := canary.Spec.TargetRef.Name
 	canaryName := fmt.Sprintf("%s-canary", targetName)

pkg/router/supergloo.go

@@ -82,11 +82,11 @@ func (sr *SuperglooRouter) Reconcile(canary *flaggerv1.Canary) error {
 	}
 
 	// do we have routes already?
-	if _, _, err := sr.GetRoutes(canary); err == nil {
+	if _, _, _, err := sr.GetRoutes(canary); err == nil {
 		// we have routes, no need to do anything else
 		return nil
 	} else if solokiterror.IsNotExist(err) {
-		return sr.SetRoutes(canary, 100, 0)
+		return sr.SetRoutes(canary, 100, 0, false)
 	} else {
 		return err
 	}
@@ -219,6 +219,7 @@ func (sr *SuperglooRouter) createRule(canary *flaggerv1.Canary, namesuffix strin
 func (sr *SuperglooRouter) GetRoutes(canary *flaggerv1.Canary) (
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 	err error,
 ) {
 	targetName := canary.Spec.TargetRef.Name
@@ -247,6 +248,8 @@ func (sr *SuperglooRouter) GetRoutes(canary *flaggerv1.Canary) (
 			targetName, canary.Namespace, targetName, targetName)
 	}
 
+	mirrored = false
+
 	return
 }
 
@@ -259,6 +262,7 @@ func (sr *SuperglooRouter) SetRoutes(
 	canary *flaggerv1.Canary,
 	primaryWeight int,
 	canaryWeight int,
+	mirrored bool,
 ) error {
 	// upstream name is
 	// in gloo-system

pkg/router/supergloo_test.go

@@ -71,15 +71,16 @@ func TestSuperglooRouter_SetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
-	p, c, err := router.GetRoutes(mocks.canary)
+	p, c, m, err := router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
 
 	p = 50
 	c = 50
+	m = false
 
-	err = router.SetRoutes(mocks.canary, p, c)
+	err = router.SetRoutes(mocks.canary, p, c, m)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -134,7 +135,7 @@ func TestSuperglooRouter_GetRoutes(t *testing.T) {
 		t.Fatal(err.Error())
 	}
 
-	p, c, err := router.GetRoutes(mocks.canary)
+	p, c, m, err := router.GetRoutes(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -146,4 +147,8 @@ func TestSuperglooRouter_GetRoutes(t *testing.T) {
 	if c != 0 {
 		t.Errorf("Got canary weight %v wanted %v", c, 0)
 	}
+
+	if m != false {
+		t.Errorf("Got mirror %v wanted %v", m, false)
+	}
 }