Add rust_log option to service related classes

Signed-off-by: mulhern <[email protected]>

tests/client-dbus/tests/udev/_utils.py

@@ -238,11 +238,14 @@ class _Service:
     """
 
     # pylint: disable=consider-using-with
-    def start_service(self):
+    def start_service(self, *, rust_log=None):
         """
         Starts the stratisd service if it is not already started. Verifies
         that it has not exited at the time the method returns. Verifies that
         the D-Bus service is available.
+
+        :param rust_log: value for RUST_LOG environment variable
+        :type rust_log: str or NoneType
         """
 
         settle()
@@ -252,6 +255,7 @@ def start_service(self):
 
         service = subprocess.Popen(
             [x for x in _STRATISD.split(" ") if x != ""],
+            env={} if rust_log is None else {"RUST_LOG": rust_log} | os.environ,
             text=True,
         )
 
@@ -359,11 +363,12 @@ class ServiceContextManager:
     A context manager for starting and stopping the daemon.
     """
 
-    def __init__(self):
+    def __init__(self, *, rust_log=None):
         self._service = _Service()
+        self._rust_log = rust_log
 
     def __enter__(self):
-        self._service.start_service()
+        self._service.start_service(rust_log=self._rust_log)
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         self._service.stop_service()
@@ -376,13 +381,15 @@ class OptionalKeyServiceContextManager:
     A service context manager that accepts an optional key
     """
 
-    def __init__(self, *, key_spec=None):
+    def __init__(self, *, key_spec=None, rust_log=None):
         """
         Initialize a context manager with an optional list of keys
         :param key_spec: Key description and data for kernel keys to be added
         :type key_spec: list of (str, str) or NoneType
+        :param rust_log: value for RUST_LOG environment variable
+        :type rust_log: str or NoneType
         """
-        self._ctxt_manager = ServiceContextManager()
+        self._ctxt_manager = ServiceContextManager(rust_log=rust_log)
         self._keys = KernelKey([]) if key_spec is None else KernelKey(key_spec)
 
     def __enter__(self):