Implement Contour router for traffic shifting

2026-04-15 06:57:34 +00:00 · 2019-12-18 19:29:17 +02:00
parent e922c3e9d9
commit ee0e7b091a
2 changed files with 203 additions and 0 deletions
@@ -0,0 +1,196 @@
+package router
+
+import (
+	"fmt"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+	"go.uber.org/zap"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/kubernetes"
+
+	flaggerv1 "github.com/weaveworks/flagger/pkg/apis/flagger/v1alpha3"
+	contourv1 "github.com/weaveworks/flagger/pkg/apis/projectcontour/v1"
+	clientset "github.com/weaveworks/flagger/pkg/client/clientset/versioned"
+)
+
+// ContourRouter is managing HTTPProxy objects
+type ContourRouter struct {
+	kubeClient    kubernetes.Interface
+	contourClient clientset.Interface
+	flaggerClient clientset.Interface
+	logger        *zap.SugaredLogger
+}
+
+// Reconcile creates or updates the HTTP proxy
+func (cr *ContourRouter) Reconcile(canary *flaggerv1.Canary) error {
+	targetName := canary.Spec.TargetRef.Name
+	primaryName := fmt.Sprintf("%s-primary", targetName)
+	canaryName := fmt.Sprintf("%s-canary", targetName)
+
+	newSpec := contourv1.HTTPProxySpec{
+		Routes: []contourv1.Route{
+			{
+				Conditions: []contourv1.Condition{
+					{
+						Prefix: "/",
+					},
+				},
+				Services: []contourv1.Service{
+					{
+						Name:   primaryName,
+						Port:   int(canary.Spec.Service.Port),
+						Weight: uint32(100),
+					},
+					{
+						Name:   canaryName,
+						Port:   int(canary.Spec.Service.Port),
+						Weight: uint32(0),
+					},
+				}},
+		},
+	}
+
+	proxy, err := cr.contourClient.ProjectcontourV1().HTTPProxies(canary.Namespace).Get(targetName, metav1.GetOptions{})
+	if errors.IsNotFound(err) {
+		proxy = &contourv1.HTTPProxy{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      targetName,
+				Namespace: canary.Namespace,
+				OwnerReferences: []metav1.OwnerReference{
+					*metav1.NewControllerRef(canary, schema.GroupVersionKind{
+						Group:   flaggerv1.SchemeGroupVersion.Group,
+						Version: flaggerv1.SchemeGroupVersion.Version,
+						Kind:    flaggerv1.CanaryKind,
+					}),
+				},
+			},
+			Spec: newSpec,
+		}
+
+		_, err = cr.contourClient.ProjectcontourV1().HTTPProxies(canary.Namespace).Create(proxy)
+		if err != nil {
+			return fmt.Errorf("HTTPProxy %s.%s create error %v", targetName, canary.Namespace, err)
+		}
+		cr.logger.With("canary", fmt.Sprintf("%s.%s", canary.Name, canary.Namespace)).
+			Infof("HTTPProxy %s.%s created", proxy.GetName(), canary.Namespace)
+		return nil
+	}
+
+	if err != nil {
+		return fmt.Errorf("HTTPProxy %s.%s query error %v", targetName, canary.Namespace, err)
+	}
+
+	// update HTTPProxy but keep the original destination weights
+	if proxy != nil {
+		if diff := cmp.Diff(
+			newSpec,
+			proxy.Spec,
+			cmpopts.IgnoreFields(contourv1.Service{}, "Weight"),
+		); diff != "" {
+			clone := proxy.DeepCopy()
+			clone.Spec = newSpec
+
+			_, err = cr.contourClient.ProjectcontourV1().HTTPProxies(canary.Namespace).Update(clone)
+			if err != nil {
+				return fmt.Errorf("HTTPProxy %s.%s update error %v", targetName, canary.Namespace, err)
+			}
+			cr.logger.With("canary", fmt.Sprintf("%s.%s", canary.Name, canary.Namespace)).
+				Infof("HTTPProxy %s.%s updated", proxy.GetName(), canary.Namespace)
+		}
+	}
+
+	return nil
+}
+
+// GetRoutes returns the service weight for primary and canary
+func (cr *ContourRouter) GetRoutes(canary *flaggerv1.Canary) (
+	primaryWeight int,
+	canaryWeight int,
+	mirrored bool,
+	err error,
+) {
+	targetName := canary.Spec.TargetRef.Name
+	primaryName := fmt.Sprintf("%s-primary", targetName)
+
+	proxy, err := cr.contourClient.ProjectcontourV1().HTTPProxies(canary.Namespace).Get(targetName, metav1.GetOptions{})
+	if err != nil {
+		if errors.IsNotFound(err) {
+			err = fmt.Errorf("HTTPProxy %s.%s not found", targetName, canary.Namespace)
+			return
+		}
+		err = fmt.Errorf("HTTPProxy %s.%s query error %v", targetName, canary.Namespace, err)
+		return
+	}
+
+	if len(proxy.Spec.Routes) < 1 || len(proxy.Spec.Routes[0].Services) < 2 {
+		err = fmt.Errorf("HTTPProxy %s.%s services not found", targetName, canary.Namespace)
+		return
+	}
+
+	for _, dst := range proxy.Spec.Routes[0].Services {
+		if dst.Name == primaryName {
+			primaryWeight = int(dst.Weight)
+			canaryWeight = 100 - primaryWeight
+			return
+		}
+	}
+
+	return
+}
+
+// SetRoutes updates the service weight for primary and canary
+func (cr *ContourRouter) SetRoutes(
+	canary *flaggerv1.Canary,
+	primaryWeight int,
+	canaryWeight int,
+	mirrored bool,
+) error {
+	targetName := canary.Spec.TargetRef.Name
+	primaryName := fmt.Sprintf("%s-primary", targetName)
+	canaryName := fmt.Sprintf("%s-canary", targetName)
+
+	if primaryWeight == 0 && canaryWeight == 0 {
+		return fmt.Errorf("HTTPProxy %s.%s update failed: no valid weights", targetName, canary.Namespace)
+	}
+
+	proxy, err := cr.contourClient.ProjectcontourV1().HTTPProxies(canary.Namespace).Get(targetName, metav1.GetOptions{})
+	if err != nil {
+		if errors.IsNotFound(err) {
+			return fmt.Errorf("HTTPProxy %s.%s not found", targetName, canary.Namespace)
+
+		}
+		return fmt.Errorf("HTTPProxy %s.%s query error %v", targetName, canary.Namespace, err)
+	}
+
+	proxy.Spec = contourv1.HTTPProxySpec{
+		Routes: []contourv1.Route{
+			{
+				Conditions: []contourv1.Condition{
+					{
+						Prefix: "/",
+					},
+				},
+				Services: []contourv1.Service{
+					{
+						Name:   primaryName,
+						Port:   int(canary.Spec.Service.Port),
+						Weight: uint32(primaryWeight),
+					},
+					{
+						Name:   canaryName,
+						Port:   int(canary.Spec.Service.Port),
+						Weight: uint32(canaryWeight),
+					},
+				}},
+		},
+	}
+
+	_, err = cr.contourClient.ProjectcontourV1().HTTPProxies(canary.Namespace).Update(proxy)
+	if err != nil {
+		return fmt.Errorf("HTTPProxy %s.%s update error %v", targetName, canary.Namespace, err)
+	}
+	return nil
+}
@@ -93,6 +93,13 @@ func (factory *Factory) MeshRouter(provider string) Interface {
 			smiClient:     factory.meshClient,
 			targetMesh:    "linkerd",
 		}
+	case provider == "contour":
+		return &ContourRouter{
+			logger:        factory.logger,
+			flaggerClient: factory.flaggerClient,
+			kubeClient:    factory.kubeClient,
+			contourClient: factory.meshClient,
+		}
 	case strings.HasPrefix(provider, "gloo"):
 		upstreamDiscoveryNs := "gloo-system"
 		if strings.HasPrefix(provider, "gloo:") {