Fix write_to_file function

src/service.py

@@ -277,25 +277,25 @@ def validate_exporter_configs(self) -> Tuple[bool, str]:
 
 
 def write_to_file(path: Path, content: str, mode: Optional[int] = None) -> bool:
-    """Write to file with provided content."""
-    success = True
+    """Write to file with provided content.
+
+    It's important to first set the permissions to then write the content because it might have
+    sensitive information like password.
+    """
     try:
-        logger.info("Writing file to %s.", path)
-        fileobj = (
-            os.fdopen(os.open(path, os.O_CREAT | os.O_WRONLY, mode), "w", encoding="utf-8")
-            if mode
-            # create file with default permissions based on default OS umask
-            else open(path, "w", encoding="utf-8")  # pylint: disable=consider-using-with
-        )
-        with fileobj as file:
+        path.touch()
+        if mode is not None:
+            os.chmod(path, mode)
+
+        with open(path, "w", encoding="utf-8") as file:
             file.write(content)
     except (NotADirectoryError, PermissionError) as err:
         logger.error(err)
         logger.info("Writing file to %s - Failed.", path)
-        success = False
-    else:
-        logger.info("Writing file to %s - Done.", path)
-    return success
+        return False
+
+    logger.info("Writing file to %s - Done.", path)
+    return True
 
 
 def remove_file(path: Path) -> bool:

tests/unit/test_service.py

@@ -783,22 +783,56 @@ def test_write_to_file_success(self, mock_os, mock_open):
 
         mock_open.assert_called_with(path, "w", encoding="utf-8")
         mock_file.write.assert_called_with(content)
+        mock_os.chmod.assert_not_called()
 
-    @mock.patch("service.os.open", new_callable=mock.mock_open)
-    @mock.patch("service.os.fdopen", new_callable=mock.mock_open)
+    def test_write_file_already_exist_changes_permission(self):
+        path = pathlib.Path(self.temp_file.name)
+        prior_permission = path.stat().st_mode & 0o777
+        new_permission = 0o666
+        self.assertNotEqual(prior_permission, new_permission)
+
+        service.write_to_file(path, "", new_permission)
+
+        after_permission = path.stat().st_mode & 0o777
+        self.assertEqual(after_permission, new_permission)
+
+    def test_write_file_changes_content(self):
+        path = pathlib.Path(self.temp_file.name)
+        content_before = (
+            "port: 10200\nlevel: DEBUG\ncollect_timeout: 60\n\nenable_collectors:\n  \n  "
+            "- collector.poweredge_raid\n  \n  - collector.ipmi_dcmi\n  \n  "
+            "- collector.ipmi_sensor\n  \n  - collector.ipmi_sel\n\n  - collector.redfish\n  "
+            "\n\nredfish_host: 'https://10.229.2.8'\nredfish_username: 'root'\n"
+            "redfish_password: '<redacted>'\nredfish_client_timeout: '60'\n"
+        )
+        with open(path, "w", encoding="utf-8") as file:
+            file.write(content_before)
+
+        # simulate the redfish disable option
+        content_after = (
+            "port: 10200\nlevel: DEBUG\ncollect_timeout: 60\n\nenable_collectors:\n  \n"
+            "  - collector.poweredge_raid\n  \n  - collector.ipmi_dcmi\n  "
+            "\n  - collector.ipmi_sensor\n  \n  - collector.ipmi_sel\n"
+        )
+
+        service.write_to_file(path, content_after)
+
+        self.assertEqual(path.read_text(), content_after)
+
+    @mock.patch("builtins.open", new_callable=mock.mock_open)
     @mock.patch("service.os")
-    def test_write_to_file_with_mode_success(self, mock_os, mock_fdopen, mock_open):
+    def test_write_to_file_with_mode_success(self, mock_os, mock_open):
         path = pathlib.Path(self.temp_file.name)
         content = "Hello, world!"
 
-        mock_file = mock_fdopen.return_value.__enter__.return_value
+        mock_file = mock_open.return_value.__enter__.return_value
 
         result = service.write_to_file(path, content, mode=0o600)
         self.assertTrue(result)
 
-        mock_open.assert_called_with(path, mock_os.O_CREAT | mock_os.O_WRONLY, 0o600)
-        mock_fdopen.assert_called_with(mock_open.return_value, "w", encoding="utf-8")
+        mock_open.assert_called_with(path, "w", encoding="utf-8")
         mock_file.write.assert_called_with(content)
+        mock_os.chmod.assert_called_with(path, 0o600)
 
     @mock.patch("builtins.open", new_callable=mock.mock_open)
     def test_write_to_file_permission_error(self, mock_open):