Fix issue where missing external IP address breaks SSH Tunnel.

Added unit test to cover missing external IP case.
Justin's feedback.
Lint fix.
Lavalmap's feedback.

pkg/master/master.go

@@ -444,15 +444,26 @@ func (n nodeAddressProvider) externalAddresses() ([]string, error) {
 	if err != nil {
 		return nil, err
 	}
+	var matchErr error
 	addrs := []string{}
 	for ix := range nodes.Items {
 		node := &nodes.Items[ix]
 		addr, err := nodeutil.GetPreferredNodeAddress(node, preferredAddressTypes)
 		if err != nil {
+			if _, ok := err.(*nodeutil.NoMatchError); ok {
+				matchErr = err
+				continue
+			}
 			return nil, err
 		}
 		addrs = append(addrs, addr)
 	}
+	if len(addrs) == 0 && matchErr != nil {
+		// We only return an error if we have items.
+		// Currently we return empty list/no error if Items is empty.
+		// We do this for backward compatibility reasons.
+		return nil, matchErr
+	}
 	return addrs, nil
 }
 

pkg/master/master_test.go

@@ -278,6 +278,22 @@ func TestGetNodeAddresses(t *testing.T) {
 	assert.Equal([]string{"127.0.0.1", "127.0.0.1"}, addrs)
 }
 
+func TestGetNodeAddressesWithOnlySomeExternalIP(t *testing.T) {
+	assert := assert.New(t)
+
+	fakeNodeClient := fake.NewSimpleClientset(makeNodeList([]string{"node1", "node2", "node3"}, apiv1.NodeResources{})).Core().Nodes()
+	addressProvider := nodeAddressProvider{fakeNodeClient}
+
+	// Pass case with 1 External type IP (index == 1) and nodes (indexes 0 & 2) have no External IP.
+	nodes, _ := fakeNodeClient.List(metav1.ListOptions{})
+	nodes.Items[1].Status.Addresses = []apiv1.NodeAddress{{Type: apiv1.NodeExternalIP, Address: "127.0.0.1"}}
+	fakeNodeClient.Update(&nodes.Items[1])
+
+	addrs, err := addressProvider.externalAddresses()
+	assert.NoError(err, "addresses should not have returned an error.")
+	assert.Equal([]string{"127.0.0.1"}, addrs)
+}
+
 func decodeResponse(resp *http.Response, obj interface{}) error {
 	defer resp.Body.Close()
 

pkg/util/node/node.go

@@ -64,6 +64,17 @@ func GetHostname(hostnameOverride string) (string, error) {
 	return strings.ToLower(hostName), nil
 }
 
+// NoMatchError is a typed implementation of the error interface. It indicates a failure to get a matching Node.
+type NoMatchError struct {
+	addresses []v1.NodeAddress
+}
+
+// Error is the implementation of the conventional interface for
+// representing an error condition, with the nil value representing no error.
+func (e *NoMatchError) Error() string {
+	return fmt.Sprintf("no preferred addresses found; known addresses: %v", e.addresses)
+}
+
 // GetPreferredNodeAddress returns the address of the provided node, using the provided preference order.
 // If none of the preferred address types are found, an error is returned.
 func GetPreferredNodeAddress(node *v1.Node, preferredAddressTypes []v1.NodeAddressType) (string, error) {
@@ -74,7 +85,7 @@ func GetPreferredNodeAddress(node *v1.Node, preferredAddressTypes []v1.NodeAddre
 			}
 		}
 	}
-	return "", fmt.Errorf("no preferred addresses found; known addresses: %v", node.Status.Addresses)
+	return "", &NoMatchError{addresses: node.Status.Addresses}
 }
 
 // GetNodeHostIP returns the provided node's IP, based on the priority: