ovs: check if list bridge/ports output is empty (#54)

Author: Yun Chen

ovs/vswitch.go

@@ -77,6 +77,9 @@ func (v *VSwitchService) ListPorts(bridge string) ([]string, error) {
 		return nil, err
 	}
 
+	if string(output) == "" {
+		return nil, nil
+	}
 	ports := strings.Split(strings.TrimSpace(string(output)), "\n")
 	return ports, err
 }
@@ -88,6 +91,9 @@ func (v *VSwitchService) ListBridges() ([]string, error) {
 		return nil, err
 	}
 
+	if string(output) == "" {
+		return nil, nil
+	}
 	bridges := strings.Split(strings.TrimSpace(string(output)), "\n")
 	return bridges, err
 }

ovs/vswitch_test.go

@@ -205,6 +205,15 @@ func TestClientVSwitchListPorts(t *testing.T) {
 		err   error
 		c     *Client
 	}{
+		{
+			name:  "test br0 bonded with no interface",
+			input: "br0",
+			want:  nil,
+			err:   nil,
+			c: testClient(nil, func(cmd string, args ...string) ([]byte, error) {
+				return []byte(""), nil
+			}),
+		},
 		{
 			name:  "test br0 bonded",
 			input: "br0",
@@ -260,6 +269,14 @@ func TestClientVSwitchListBridges(t *testing.T) {
 		err  error
 		c    *Client
 	}{
+		{
+			name: "test no bridge",
+			want: nil,
+			err:  nil,
+			c: testClient(nil, func(cmd string, args ...string) ([]byte, error) {
+				return []byte(""), nil
+			}),
+		},
 		{
 			name: "test single bridge",
 			want: []string{"br0"},