Allow custom value for kubernetes.io/ingress.class annotation

cmd/traefik/configuration.go

@@ -130,8 +130,6 @@ func NewTraefikDefaultPointersConfiguration() *TraefikConfiguration {
 	//default Kubernetes
 	var defaultKubernetes kubernetes.Provider
 	defaultKubernetes.Watch = true
-	defaultKubernetes.Endpoint = ""
-	defaultKubernetes.LabelSelector = ""
 	defaultKubernetes.Constraints = types.Constraints{}
 
 	// default Mesos

docs/configuration/backends/kubernetes.md

@@ -50,6 +50,17 @@ See also [Kubernetes user guide](/user-guide/kubernetes).
 #
 # labelselector = "A and not B"
 
+# Value of `kubernetes.io/ingress.class` annotation that identifies Ingress objects to be processed.
+# If the parameter is non-empty, only Ingresses containing an annotation with the same value are processed.
+# Otherwise, Ingresses missing the annotation, having an empty value, or the value `traefik` are processed.
+#
+# Note : `ingressClass` option must begin with the "traefik" prefix.
+#
+# Optional
+# Default: empty
+#
+# ingressClass = "traefik-internal"
+
 # Disable PassHost Headers.
 #
 # Optional

provider/kubernetes/kubernetes.go

@@ -32,8 +32,8 @@ var _ provider.Provider = (*Provider)(nil)
 const (
 	ruleTypePathPrefix         = "PathPrefix"
 	ruleTypeReplacePath        = "ReplacePath"
-
 	traefikDefaultRealm        = "traefik"
+	traefikDefaultIngressClass = "traefik"
 )
 
 // Provider holds configurations of the provider.
@@ -46,6 +46,7 @@ type Provider struct {
 	EnablePassTLSCert      bool       `description:"Kubernetes enable Pass TLS Client Certs" export:"true"`
 	Namespaces             Namespaces `description:"Kubernetes namespaces" export:"true"`
 	LabelSelector          string     `description:"Kubernetes api label selector to use" export:"true"`
+	IngressClass           string     `description:"Value of kubernetes.io/ingress.class annotation to watch for" export:"true"`
 	lastConfiguration      safe.Safe
 }
 
@@ -76,6 +77,12 @@ func (p *Provider) Provide(configurationChan chan<- types.ConfigMessage, pool *s
 		return err
 	}
 
+	// We require that IngressClasses start with `traefik` to reduce chances of
+	// conflict with other Ingress Providers
+	if len(p.IngressClass) > 0 && !strings.HasPrefix(p.IngressClass, traefikDefaultIngressClass) {
+		return fmt.Errorf("value for IngressClass has to be empty or start with the prefix %q, instead found %q", traefikDefaultIngressClass, p.IngressClass)
+	}
+
 	k8sClient, err := p.newK8sClient()
 	if err != nil {
 		return err
@@ -147,7 +154,7 @@ func (p *Provider) loadIngresses(k8sClient Client) (*types.Configuration, error)
 		annotationIngressClass := getAnnotationName(i.Annotations, annotationKubernetesIngressClass)
 		ingressClass := i.Annotations[annotationIngressClass]
 
-		if !shouldProcessIngress(ingressClass) {
+		if !p.shouldProcessIngress(ingressClass) {
 			continue
 		}
 
@@ -451,8 +458,11 @@ func equalPorts(servicePort v1.ServicePort, ingressPort intstr.IntOrString) bool
 	return false
 }
 
-func shouldProcessIngress(ingressClass string) bool {
+func (p *Provider) shouldProcessIngress(annotationIngressClass string) bool {
-	return ingressClass == "" || ingressClass == "traefik"
+	if len(p.IngressClass) == 0 {
+		return len(annotationIngressClass) == 0 || annotationIngressClass == traefikDefaultIngressClass
+	}
+	return annotationIngressClass == p.IngressClass
 }
 
 func getFrontendRedirect(i *v1beta1.Ingress) *types.Redirect {

provider/kubernetes/kubernetes_test.go

@@ -616,7 +616,7 @@ func TestIngressAnnotations(t *testing.T) {
 		buildIngress(
 			iNamespace("testing"),
 			iAnnotation(annotationKubernetesPreserveHost, "true"),
-			iAnnotation(annotationKubernetesIngressClass, "traefik"),
+			iAnnotation(annotationKubernetesIngressClass, traefikDefaultRealm),
 			iRules(
 				iRule(
 					iHost("other"),
@@ -626,7 +626,7 @@ func TestIngressAnnotations(t *testing.T) {
 		buildIngress(
 			iNamespace("testing"),
 			iAnnotation(annotationKubernetesPassTLSCert, "true"),
-			iAnnotation(annotationKubernetesIngressClass, "traefik"),
+			iAnnotation(annotationKubernetesIngressClass, traefikDefaultRealm),
 			iRules(
 				iRule(
 					iHost("other"),
@@ -636,7 +636,7 @@ func TestIngressAnnotations(t *testing.T) {
 		buildIngress(
 			iNamespace("testing"),
 			iAnnotation(annotationKubernetesFrontendEntryPoints, "http,https"),
-			iAnnotation(annotationKubernetesIngressClass, "traefik"),
+			iAnnotation(annotationKubernetesIngressClass, traefikDefaultRealm),
 			iRules(
 				iRule(
 					iHost("other"),
@@ -655,7 +655,7 @@ func TestIngressAnnotations(t *testing.T) {
 		),
 		buildIngress(
 			iNamespace("testing"),
-			iAnnotation(annotationKubernetesIngressClass, "somethingOtherThanTraefik"),
+			iAnnotation(annotationKubernetesIngressClass, traefikDefaultRealm+"-other"),
 			iRules(
 				iRule(
 					iHost("herp"),
@@ -664,7 +664,6 @@ func TestIngressAnnotations(t *testing.T) {
 		),
 		buildIngress(
 			iNamespace("testing"),
-			iAnnotation(annotationKubernetesIngressClass, "traefik"),
 			iAnnotation(annotationKubernetesWhitelistSourceRange, "1.1.1.1/24, 1234:abcd::42/32"),
 			iRules(
 				iRule(
@@ -692,7 +691,6 @@ func TestIngressAnnotations(t *testing.T) {
 		),
 		buildIngress(
 			iNamespace("testing"),
-			iAnnotation(annotationKubernetesIngressClass, "traefik"),
 			iAnnotation(annotationKubernetesRedirectEntryPoint, "https"),
 			iRules(
 				iRule(
@@ -790,14 +788,16 @@ rateset:
 		),
 	}
 
-	secrets := []*v1.Secret{{
+	secrets := []*v1.Secret{
+		{
 			ObjectMeta: v1.ObjectMeta{
 				Name:      "mySecret",
 				UID:       "1",
 				Namespace: "testing",
 			},
 			Data: map[string][]byte{"auth": []byte("myUser:myEncodedPW")},
-	}}
+		},
+	}
 
 	watchChan := make(chan interface{})
 	client := clientMock{
@@ -999,6 +999,153 @@ rateset:
 	assert.Equal(t, expected, actual)
 }
 
+func TestIngressClassAnnotation(t *testing.T) {
+	ingresses := []*v1beta1.Ingress{
+		buildIngress(
+			iNamespace("testing"),
+			iAnnotation(annotationKubernetesIngressClass, traefikDefaultIngressClass),
+			iRules(
+				iRule(
+					iHost("other"),
+					iPaths(onePath(iPath("/stuff"), iBackend("service1", intstr.FromInt(80))))),
+			),
+		),
+		buildIngress(
+			iNamespace("testing"),
+			iAnnotation(annotationKubernetesIngressClass, ""),
+			iRules(
+				iRule(
+					iHost("other"),
+					iPaths(onePath(iPath("/sslstuff"), iBackend("service1", intstr.FromInt(80))))),
+			),
+		),
+		buildIngress(
+			iNamespace("testing"),
+			iRules(
+				iRule(
+					iHost("other"),
+					iPaths(onePath(iPath("/"), iBackend("service1", intstr.FromInt(80))))),
+			),
+		),
+		buildIngress(
+			iNamespace("testing"),
+			iAnnotation(annotationKubernetesIngressClass, traefikDefaultIngressClass+"-other"),
+			iRules(
+				iRule(
+					iHost("herp"),
+					iPaths(onePath(iPath("/derp"), iBackend("service1", intstr.FromInt(80))))),
+			),
+		),
+	}
+
+	services := []*v1.Service{
+		buildService(
+			sName("service1"),
+			sNamespace("testing"),
+			sUID("1"),
+			sSpec(
+				clusterIP("10.0.0.1"),
+				sType("ExternalName"),
+				sExternalName("example.com"),
+				sPorts(sPort(80, "http"))),
+		),
+	}
+
+	watchChan := make(chan interface{})
+	client := clientMock{
+		ingresses: ingresses,
+		services:  services,
+		watchChan: watchChan,
+	}
+
+	testCases := []struct {
+		desc     string
+		provider Provider
+		expected *types.Configuration
+	}{
+		{
+			desc:     "Empty IngressClass annotation",
+			provider: Provider{},
+			expected: buildConfiguration(
+				backends(
+					backend("other/stuff",
+						servers(
+							server("http://example.com", weight(1)),
+							server("http://example.com", weight(1))),
+						lbMethod("wrr"),
+					),
+					backend("other/",
+						servers(
+							server("http://example.com", weight(1)),
+							server("http://example.com", weight(1))),
+						lbMethod("wrr"),
+					),
+					backend("other/sslstuff",
+						servers(
+							server("http://example.com", weight(1)),
+							server("http://example.com", weight(1))),
+						lbMethod("wrr"),
+					),
+				),
+				frontends(
+					frontend("other/stuff",
+						passHostHeader(),
+						routes(
+							route("/stuff", "PathPrefix:/stuff"),
+							route("other", "Host:other")),
+					),
+					frontend("other/",
+						passHostHeader(),
+						routes(
+							route("/", "PathPrefix:/"),
+							route("other", "Host:other")),
+					),
+					frontend("other/sslstuff",
+						passHostHeader(),
+						routes(
+							route("/sslstuff", "PathPrefix:/sslstuff"),
+							route("other", "Host:other")),
+					),
+				),
+			),
+		},
+		{
+			desc:     "Provided IngressClass annotation",
+			provider: Provider{IngressClass: traefikDefaultRealm + "-other"},
+			expected: buildConfiguration(
+				backends(
+					backend("herp/derp",
+						servers(
+							server("http://example.com", weight(1)),
+							server("http://example.com", weight(1))),
+						lbMethod("wrr"),
+					),
+				),
+				frontends(
+					frontend("herp/derp",
+						passHostHeader(),
+						routes(
+							route("/derp", "PathPrefix:/derp"),
+							route("herp", "Host:herp")),
+					),
+				),
+			),
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			actual, err := test.provider.loadIngresses(client)
+			require.NoError(t, err, "error loading ingresses")
+
+			assert.Equal(t, test.expected, actual)
+		})
+	}
+}
+
 func TestPriorityHeaderValue(t *testing.T) {
 	ingresses := []*v1beta1.Ingress{
 		buildIngress(