Allow tls section without hosts in Ingress rule

internal/ingress/controller/controller.go

@@ -1007,20 +1007,7 @@ func (n *NGINXController) createServers(data []*extensions.Ingress,
 				continue
 			}
 
-			tlsSecretName := ""
-			found := false
-			for _, tls := range ing.Spec.TLS {
-				if sets.NewString(tls.Hosts...).Has(host) {
-					tlsSecretName = tls.SecretName
-					found = true
-					break
-				}
-			}
-
-			if !found {
-				// does not contains a TLS section but none of the host match
-				continue
-			}
+			tlsSecretName := extractTLSSecretName(host, ing, n.store.GetLocalSSLCert)
 
 			if tlsSecretName == "" {
 				glog.V(3).Infof("host %v is listed on tls section but secretName is empty. Using default cert", host)
@@ -1174,3 +1161,41 @@ func (n *NGINXController) SetForceReload(shouldReload bool) {
 		atomic.StoreInt32(&n.forceReload, 0)
 	}
 }
+
+// extractTLSSecretName returns the name of the secret that
+// contains a SSL certificate for a particular hostname.
+// In case there is no match, an empty string is returned.
+func extractTLSSecretName(host string, ing *extensions.Ingress,
+	getLocalSSLCert func(string) (*ingress.SSLCert, error)) string {
+	if ing == nil {
+		return ""
+	}
+
+	for _, tls := range ing.Spec.TLS {
+		if sets.NewString(tls.Hosts...).Has(host) {
+			return tls.SecretName
+		}
+	}
+
+	// contains a TLS section but none of the host match or there
+	// is no hosts in the TLS section. As last resort we valide
+	// the host against the certificate and we use it if is valid
+	for _, tls := range ing.Spec.TLS {
+		key := fmt.Sprintf("%v/%v", ing.Namespace, tls.SecretName)
+		cert, err := getLocalSSLCert(key)
+		if err != nil {
+			glog.Warningf("ssl certificate \"%v\" does not exist in local store", key)
+			continue
+		}
+
+		if cert == nil {
+			continue
+		}
+
+		if sets.NewString(cert.CN...).Has(host) {
+			return tls.SecretName
+		}
+	}
+
+	return ""
+}

internal/ingress/controller/controller_test.go

@@ -0,0 +1,131 @@
+/*
+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 controller
+
+import (
+	"testing"
+
+	extensions "k8s.io/api/extensions/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/ingress-nginx/internal/ingress"
+)
+
+func TestExtractTLSSecretName(t *testing.T) {
+	tests := []struct {
+		host    string
+		ingress *extensions.Ingress
+		fn      func(string) (*ingress.SSLCert, error)
+		expName string
+	}{
+		{
+			"foo.bar",
+			nil,
+			func(string) (*ingress.SSLCert, error) {
+				return nil, nil
+			},
+			"",
+		},
+		{
+			"foo.bar",
+			&extensions.Ingress{},
+			func(string) (*ingress.SSLCert, error) {
+				return nil, nil
+			},
+			"",
+		},
+		{
+			"foo.bar",
+			&extensions.Ingress{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test",
+				},
+				Spec: extensions.IngressSpec{
+					TLS: []extensions.IngressTLS{
+						{SecretName: "demo"},
+					},
+					Rules: []extensions.IngressRule{
+						{
+							Host: "foo.bar",
+						},
+					},
+				},
+			},
+			func(string) (*ingress.SSLCert, error) {
+				return nil, nil
+			},
+			"",
+		},
+		{
+			"foo.bar",
+			&extensions.Ingress{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test",
+				},
+				Spec: extensions.IngressSpec{
+					TLS: []extensions.IngressTLS{
+						{SecretName: "demo"},
+					},
+					Rules: []extensions.IngressRule{
+						{
+							Host: "foo.bar",
+						},
+					},
+				},
+			},
+			func(string) (*ingress.SSLCert, error) {
+				return &ingress.SSLCert{
+					CN: []string{"foo.bar", "example.com"},
+				}, nil
+			},
+			"demo",
+		},
+		{
+			"foo.bar",
+			&extensions.Ingress{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test",
+				},
+				Spec: extensions.IngressSpec{
+					TLS: []extensions.IngressTLS{
+						{
+							Hosts:      []string{"foo.bar", "example.com"},
+							SecretName: "demo",
+						},
+					},
+					Rules: []extensions.IngressRule{
+						{
+							Host: "foo.bar",
+						},
+					},
+				},
+			},
+			func(string) (*ingress.SSLCert, error) {
+				return &ingress.SSLCert{
+					CN: []string{"foo.bar", "example.com"},
+				}, nil
+			},
+			"demo",
+		},
+	}
+
+	for _, testCase := range tests {
+		name := extractTLSSecretName(testCase.host, testCase.ingress, testCase.fn)
+		if name != testCase.expName {
+			t.Errorf("expected %v as the name of the secret but got %v", testCase.expName, name)
+		}
+	}
+}