Add ImageService.set_next_boot for GNOI Activate OS. (#207)

* Add ImageService.set_next_boot for GNOI Activate OS.

* address copilot comment.

* more logs.

* update unit test.

Author: hdwhdw

host_modules/image_service.py

@@ -160,6 +160,27 @@ def list_images(self):
             logger.error(msg)
             return e.returncode, msg
 
+    @host_service.method(
+        host_service.bus_name(MOD_NAME), in_signature="s", out_signature="is"
+    )
+    def set_next_boot(self, image):
+        """
+        Set the image to be used for the next boot.
+
+        Args:
+            image: The name of the image to set for the next boot.
+        """
+        logger.info("Setting the next boot image to {}".format(image))
+        cmd = ["/usr/local/bin/sonic-installer", "set-next-boot", image]
+        result = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        msg = "Boot image set to {}".format(image)
+        logger.info(msg)
+        if result.returncode:
+            logger.error("Failed to set next boot image: {}".format(result.stderr.decode()))
+            msg = result.stderr.decode()
+        return result.returncode, msg
+
+
     def _parse_sonic_installer_list(self, output):
         """
         Parse the output of the sonic-installer list command.

tests/host_modules/image_service_test.py

@@ -568,3 +568,59 @@ def test_list_images_failed(self, mock_check_output, MockInit, MockBusName, Mock
             stderr=subprocess.STDOUT,
         )
 
+    @mock.patch("dbus.SystemBus")
+    @mock.patch("dbus.service.BusName")
+    @mock.patch("dbus.service.Object.__init__")
+    @mock.patch("subprocess.run")
+    def test_image_set_next_boot_success(self, mock_run, MockInit, MockBusName, MockSystemBus):
+        """
+        Test that the `set_next_boot` method successfully sets the next boot image.
+        """
+        # Arrange
+        image_service = ImageService(mod_name="image_service")
+        image = "sonic_image"
+        mock_result = mock.Mock()
+        mock_result.returncode = 0
+        mock_result.stderr = b""
+        mock_run.return_value = mock_result
+
+        # Act
+        rc, msg = image_service.set_next_boot(image)
+
+        # Assert
+        assert rc == 0, "wrong return value"
+        assert image in msg, "message should contain the name of the new image"
+        mock_run.assert_called_once_with(
+            ["/usr/local/bin/sonic-installer", "set-next-boot", image],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+
+    @mock.patch("dbus.SystemBus")
+    @mock.patch("dbus.service.BusName")
+    @mock.patch("dbus.service.Object.__init__")
+    @mock.patch("subprocess.run")
+    def test_image_set_next_boot_fail_not_exists(self, mock_run, MockInit, MockBusName, MockSystemBus):
+        """
+        Test that the `set_next_boot` method fails when the image does not exist.
+        """
+        # Arrange
+        image_service = ImageService(mod_name="image_service")
+        image = "nonexistent_image"
+        mock_result = mock.Mock()
+        mock_result.returncode = 1
+        mock_result.stderr = b"Error: Image does not exist"
+        mock_run.return_value = mock_result
+
+        # Act
+        rc, msg = image_service.set_next_boot(image)
+
+        # Assert
+        assert rc != 0, "wrong return value"
+        assert "Error: Image does not exist" in msg, "message should contain 'Error: Image does not exist'"
+        mock_run.assert_called_once_with(
+            ["/usr/local/bin/sonic-installer", "set-next-boot", image],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+