Merge pull request #526 from DataDog/affinity-support

BackendConfig support for session affinity

pkg/apis/backendconfig/v1beta1/types.go

@@ -41,6 +41,7 @@ type BackendConfigSpec struct {
 	SecurityPolicy     *SecurityPolicyConfig     `json:"securityPolicy,omitempty"`
 	TimeoutSec         *int64                    `json:"timeoutSec,omitempty"`
 	ConnectionDraining *ConnectionDrainingConfig `json:"connectionDraining,omitempty"`
+	SessionAffinity    *SessionAffinityConfig    `json:"sessionAffinity,omitempty"`
 }
 
 // BackendConfigStatus is the status for a BackendConfig resource
@@ -115,5 +116,12 @@ type SecurityPolicyConfig struct {
 // +k8s:openapi-gen=true
 type ConnectionDrainingConfig struct {
 	// Draining timeout in seconds.
-	DrainingTimeoutSec *int64 `json:"drainingTimeoutSec,omitempty"`
+	DrainingTimeoutSec int64 `json:"drainingTimeoutSec,omitempty"`
+}
+
+// SessionAffinityConfig contains configuration for stickyness parameters.
+// +k8s:openapi-gen=true
+type SessionAffinityConfig struct {
+	AffinityType         string `json:"affinityType,omitempty"`
+	AffinityCookieTtlSec *int64 `json:"affinityCookieTtlSec,omitempty"`
 }

pkg/backendconfig/validation.go

@@ -29,11 +29,26 @@ const (
 	OAuthClientSecretKey = "client_secret"
 )
 
+var supportedAffinities = map[string]bool{
+	"NONE":             true,
+	"CLIENT_IP":        true,
+	"GENERATED_COOKIE": true,
+}
+
 func Validate(kubeClient kubernetes.Interface, beConfig *backendconfigv1beta1.BackendConfig) error {
 	if beConfig == nil {
 		return nil
 	}
-	return validateIAP(kubeClient, beConfig)
+
+	if err := validateIAP(kubeClient, beConfig); err != nil {
+		return err
+	}
+
+	if err := validateSessionAffinity(kubeClient, beConfig); err != nil {
+		return err
+	}
+
+	return nil
 }
 
 // TODO(rramkumar): Return errors as constants so that the unit tests can distinguish
@@ -67,3 +82,25 @@ func validateIAP(kubeClient kubernetes.Interface, beConfig *backendconfigv1beta1
 	}
 	return nil
 }
+
+func validateSessionAffinity(kubeClient kubernetes.Interface, beConfig *backendconfigv1beta1.BackendConfig) error {
+	if beConfig.Spec.SessionAffinity == nil {
+		return nil
+	}
+
+	if beConfig.Spec.SessionAffinity.AffinityType != "" {
+		if _, ok := supportedAffinities[beConfig.Spec.SessionAffinity.AffinityType]; !ok {
+			return fmt.Errorf("unsupported AffinityType: %s, should be one of NONE, CLIENT_IP, or GENERATED_COOKIE",
+				beConfig.Spec.SessionAffinity.AffinityType)
+		}
+	}
+
+	if beConfig.Spec.SessionAffinity.AffinityCookieTtlSec != nil {
+		if *beConfig.Spec.SessionAffinity.AffinityCookieTtlSec < 0 || *beConfig.Spec.SessionAffinity.AffinityCookieTtlSec > 86400 {
+			return fmt.Errorf("unsupported AffinityCookieTtlSec: %d, should be between 0 and 86400",
+				*beConfig.Spec.SessionAffinity.AffinityCookieTtlSec)
+		}
+	}
+
+	return nil
+}

pkg/backendconfig/validation_test.go

@@ -27,6 +27,9 @@ import (
 )
 
 var (
+	goodTTL int64 = 86400
+	badTTL  int64 = 86400 + 1
+
 	defaultBeConfig = &backendconfigv1beta1.BackendConfig{
 		ObjectMeta: meta_v1.ObjectMeta{
 			Namespace: "default",
@@ -159,3 +162,80 @@ func TestValidateIAP(t *testing.T) {
 		}
 	}
 }
+
+func TestValidateSessionAffinity(t *testing.T) {
+	testCases := []struct {
+		desc        string
+		beConfig    *backendconfigv1beta1.BackendConfig
+		expectError bool
+	}{
+
+		{
+			desc: "unsupported affinity type",
+			beConfig: &backendconfigv1beta1.BackendConfig{
+				ObjectMeta: meta_v1.ObjectMeta{
+					Namespace: "default",
+				},
+				Spec: backendconfigv1beta1.BackendConfigSpec{
+					SessionAffinity: &backendconfigv1beta1.SessionAffinityConfig{
+						AffinityType: "WRONG_TYPE",
+					},
+				},
+			},
+			expectError: true,
+		},
+		{
+			desc: "supported affinity type",
+			beConfig: &backendconfigv1beta1.BackendConfig{
+				ObjectMeta: meta_v1.ObjectMeta{
+					Namespace: "default",
+				},
+				Spec: backendconfigv1beta1.BackendConfigSpec{
+					SessionAffinity: &backendconfigv1beta1.SessionAffinityConfig{
+						AffinityType: "CLIENT_IP",
+					},
+				},
+			},
+			expectError: false,
+		},
+		{
+			desc: "unsupported ttl value",
+			beConfig: &backendconfigv1beta1.BackendConfig{
+				ObjectMeta: meta_v1.ObjectMeta{
+					Namespace: "default",
+				},
+				Spec: backendconfigv1beta1.BackendConfigSpec{
+					SessionAffinity: &backendconfigv1beta1.SessionAffinityConfig{
+						AffinityCookieTtlSec: &badTTL,
+					},
+				},
+			},
+			expectError: true,
+		},
+		{
+			desc: "supported ttl value",
+			beConfig: &backendconfigv1beta1.BackendConfig{
+				ObjectMeta: meta_v1.ObjectMeta{
+					Namespace: "default",
+				},
+				Spec: backendconfigv1beta1.BackendConfigSpec{
+					SessionAffinity: &backendconfigv1beta1.SessionAffinityConfig{
+						AffinityCookieTtlSec: &goodTTL,
+					},
+				},
+			},
+			expectError: false,
+		},
+	}
+
+	for _, testCase := range testCases {
+		kubeClient := fake.NewSimpleClientset()
+		err := Validate(kubeClient, testCase.beConfig)
+		if testCase.expectError && err == nil {
+			t.Errorf("%v: Expected error but got nil", testCase.desc)
+		}
+		if !testCase.expectError && err != nil {
+			t.Errorf("%v: Did not expect error but got: %v", testCase.desc, err)
+		}
+	}
+}

pkg/backends/features/affinity.go

@@ -0,0 +1,53 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package features
+
+import (
+	"reflect"
+
+	"github.com/golang/glog"
+	"k8s.io/ingress-gce/pkg/composite"
+	"k8s.io/ingress-gce/pkg/utils"
+)
+
+// EnsureAffinity reads the sessionAffinity and AffinityCookieTtlSec configuration
+// specified in the ServicePort.BackendConfig and applies it to the BackendService.
+// It returns true if there were existing settings on the BackendService
+// that were overwritten.
+func EnsureAffinity(sp utils.ServicePort, be *composite.BackendService) bool {
+	if sp.BackendConfig.Spec.SessionAffinity == nil {
+		return false
+	}
+	beTemp := &composite.BackendService{}
+	applyAffinitySettings(sp, beTemp)
+	if !reflect.DeepEqual(beTemp.AffinityCookieTtlSec, be.AffinityCookieTtlSec) || beTemp.SessionAffinity != be.SessionAffinity {
+		applyAffinitySettings(sp, be)
+		glog.V(2).Infof("Updated SessionAffinity settings for service %v/%v.", sp.ID.Service.Namespace, sp.ID.Service.Name)
+		return true
+	}
+	return false
+}
+
+// applyAffinitySettings applies the session affinity settings specified in the
+// BackendConfig to the passed in composite.BackendService. A GCE API call still
+// needs to be made to actually persist the changes.
+func applyAffinitySettings(sp utils.ServicePort, be *composite.BackendService) {
+	be.SessionAffinity = sp.BackendConfig.Spec.SessionAffinity.AffinityType
+	if sp.BackendConfig.Spec.SessionAffinity.AffinityCookieTtlSec != nil {
+		be.AffinityCookieTtlSec = *sp.BackendConfig.Spec.SessionAffinity.AffinityCookieTtlSec
+	}
+}