Merge pull request #3341 from Shopify/canary_upstream

Add canary annotation and alternative backends for traffic shaping

internal/ingress/annotations/annotations.go

@@ -19,6 +19,7 @@ package annotations
 import (
 	"github.com/golang/glog"
 	"github.com/imdario/mergo"
+	"k8s.io/ingress-nginx/internal/ingress/annotations/canary"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/sslcipher"
 
 	apiv1 "k8s.io/api/core/v1"
@@ -68,6 +69,7 @@ type Ingress struct {
 	BackendProtocol      string
 	Alias                string
 	BasicDigestAuth      auth.Config
+	Canary               canary.Config
 	CertificateAuth      authtls.Config
 	ClientBodyBufferSize string
 	ConfigurationSnippet string
@@ -109,6 +111,7 @@ func NewAnnotationExtractor(cfg resolver.Resolver) Extractor {
 		map[string]parser.IngressAnnotation{
 			"Alias":                alias.NewParser(cfg),
 			"BasicDigestAuth":      auth.NewParser(auth.AuthDirectory, cfg),
+			"Canary":               canary.NewParser(cfg),
 			"CertificateAuth":      authtls.NewParser(cfg),
 			"ClientBodyBufferSize": clientbodybuffersize.NewParser(cfg),
 			"ConfigurationSnippet": snippet.NewParser(cfg),

internal/ingress/annotations/canary/main.go

@@ -0,0 +1,75 @@
+/*
+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 canary
+
+import (
+	extensions "k8s.io/api/extensions/v1beta1"
+
+	"k8s.io/ingress-nginx/internal/ingress/annotations/parser"
+	"k8s.io/ingress-nginx/internal/ingress/errors"
+	"k8s.io/ingress-nginx/internal/ingress/resolver"
+)
+
+type canary struct {
+	r resolver.Resolver
+}
+
+// Config returns the configuration rules for setting up the Canary
+type Config struct {
+	Enabled bool
+	Weight  int
+	Header  string
+	Cookie  string
+}
+
+// NewParser parses the ingress for canary related annotations
+func NewParser(r resolver.Resolver) parser.IngressAnnotation {
+	return canary{r}
+}
+
+// Parse parses the annotations contained in the ingress
+// rule used to indicate if the canary should be enabled and with what config
+func (c canary) Parse(ing *extensions.Ingress) (interface{}, error) {
+	config := &Config{}
+	var err error
+
+	config.Enabled, err = parser.GetBoolAnnotation("canary", ing)
+	if err != nil {
+		config.Enabled = false
+	}
+
+	config.Weight, err = parser.GetIntAnnotation("canary-weight", ing)
+	if err != nil {
+		config.Weight = 0
+	}
+
+	config.Header, err = parser.GetStringAnnotation("canary-by-header", ing)
+	if err != nil {
+		config.Header = ""
+	}
+
+	config.Cookie, err = parser.GetStringAnnotation("canary-by-cookie", ing)
+	if err != nil {
+		config.Cookie = ""
+	}
+
+	if !config.Enabled && (config.Weight > 0 || len(config.Header) > 0 || len(config.Cookie) > 0) {
+		return nil, errors.NewInvalidAnnotationConfiguration("canary", "configured but not enabled")
+	}
+
+	return config, nil
+}

internal/ingress/annotations/canary/main_test.go

@@ -0,0 +1,126 @@
+/*
+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 canary
+
+import (
+	api "k8s.io/api/core/v1"
+	extensions "k8s.io/api/extensions/v1beta1"
+	metaV1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/intstr"
+	"k8s.io/ingress-nginx/internal/ingress/annotations/parser"
+	"testing"
+
+	"k8s.io/ingress-nginx/internal/ingress/resolver"
+	"strconv"
+)
+
+func buildIngress() *extensions.Ingress {
+	defaultBackend := extensions.IngressBackend{
+		ServiceName: "default-backend",
+		ServicePort: intstr.FromInt(80),
+	}
+
+	return &extensions.Ingress{
+		ObjectMeta: metaV1.ObjectMeta{
+			Name:      "foo",
+			Namespace: api.NamespaceDefault,
+		},
+		Spec: extensions.IngressSpec{
+			Backend: &extensions.IngressBackend{
+				ServiceName: "default-backend",
+				ServicePort: intstr.FromInt(80),
+			},
+			Rules: []extensions.IngressRule{
+				{
+					Host: "foo.bar.com",
+					IngressRuleValue: extensions.IngressRuleValue{
+						HTTP: &extensions.HTTPIngressRuleValue{
+							Paths: []extensions.HTTPIngressPath{
+								{
+									Path:    "/foo",
+									Backend: defaultBackend,
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func TestAnnotations(t *testing.T) {
+	ing := buildIngress()
+
+	data := map[string]string{}
+	ing.SetAnnotations(data)
+
+	tests := []struct {
+		title         string
+		canaryEnabled bool
+		canaryWeight  int
+		canaryHeader  string
+		canaryCookie  string
+		expErr        bool
+	}{
+		{"canary disabled and no weight", false, 0, "", "", false},
+		{"canary disabled and weight", false, 20, "", "", true},
+		{"canary disabled and header", false, 0, "X-Canary", "", true},
+		{"canary disabled and cookie", false, 0, "", "canary_enabled", true},
+		{"canary enabled and weight", true, 20, "", "", false},
+		{"canary enabled and no weight", true, 0, "", "", false},
+		{"canary enabled by header", true, 20, "X-Canary", "", false},
+		{"canary enabled by cookie", true, 20, "", "canary_enabled", false},
+	}
+
+	for _, test := range tests {
+		data[parser.GetAnnotationWithPrefix("canary")] = strconv.FormatBool(test.canaryEnabled)
+		data[parser.GetAnnotationWithPrefix("canary-weight")] = strconv.Itoa(test.canaryWeight)
+		data[parser.GetAnnotationWithPrefix("canary-by-header")] = test.canaryHeader
+		data[parser.GetAnnotationWithPrefix("canary-by-cookie")] = test.canaryCookie
+
+		i, err := NewParser(&resolver.Mock{}).Parse(ing)
+		if test.expErr {
+			if err == nil {
+				t.Errorf("%v: expected error but returned nil", test.title)
+			}
+
+			continue
+		} else {
+			if err != nil {
+				t.Errorf("%v: expected nil but returned error %v", test.title, err)
+			}
+		}
+
+		canaryConfig, ok := i.(*Config)
+		if !ok {
+			t.Errorf("%v: expected an External type", test.title)
+		}
+		if canaryConfig.Enabled != test.canaryEnabled {
+			t.Errorf("%v: expected \"%v\", but \"%v\" was returned", test.title, test.canaryEnabled, canaryConfig.Enabled)
+		}
+		if canaryConfig.Weight != test.canaryWeight {
+			t.Errorf("%v: expected \"%v\", but \"%v\" was returned", test.title, test.canaryWeight, canaryConfig.Weight)
+		}
+		if canaryConfig.Header != test.canaryHeader {
+			t.Errorf("%v: expected \"%v\", but \"%v\" was returned", test.title, test.canaryHeader, canaryConfig.Header)
+		}
+		if canaryConfig.Cookie != test.canaryCookie {
+			t.Errorf("%v: expected \"%v\", but \"%v\" was returned", test.title, test.canaryCookie, canaryConfig.Cookie)
+		}
+	}
+}