Cgroup rewrite: uses systemctl for expressing desired configuration instead drop-in files

azurelinuxagent/agent.py

@@ -226,6 +226,8 @@ def collect_logs(self, is_full_mode):
 
             log_collector_cgroup = cgroup_api.get_process_cgroup(process_id="self", cgroup_name=AGENT_LOG_COLLECTOR)
             tracked_controllers = log_collector_cgroup.get_controllers()
+            for controller in tracked_controllers:
+                logger.info("{0} controller for cgroup: {1}".format(controller.get_controller_type(), controller))
 
             if len(tracked_controllers) != len(log_collector_cgroup.get_supported_controller_names()):
                 event.warn(WALAEventOperation.LogCollection, "At least one required controller is missing. The following controllers are required for the log collector to run: {0}", log_collector_cgroup.get_supported_controller_names())

azurelinuxagent/common/osutil/systemd.py

@@ -84,3 +84,39 @@ def get_unit_property(unit_name, property_name):
         raise ValueError("Can't find property {0} of {1}".format(property_name, unit_name))
     return match.group('value')
 
+
+def set_unit_property_run_time(unit_name, property_name, value):
+    """
+    Set a property of a unit at runtime
+
+    Note: --runtime settings only apply until the next reboot
+    """
+    try:
+        # Ex: systemctl set-property foobar.service CPUWeight=200 --runtime
+        shellutil.run_command(["systemctl", "set-property", unit_name, "{0}={1}".format(property_name, value), "--runtime"])
+    except shellutil.CommandError as e:
+        raise ValueError("Can't set property {0} of {1}: {2}".format(property_name, unit_name, e))
+
+
+def set_unit_properties_run_time(unit_name, properties):
+    """
+    Set multiple properties of a unit at runtime
+
+    Note: --runtime settings only apply until the next reboot
+    """
+    try:
+        # Ex: systemctl set-property foobar.service CPUWeight=200 MemoryMax=2G IPAccounting=yes --runtime
+        shellutil.run_command(["systemctl", "set-property", unit_name] + properties + ["--runtime"])
+    except shellutil.CommandError as e:
+        raise ValueError("Can't set properties {0} of {1}: {2}".format(properties, unit_name, e))
+
+
+def is_unit_loaded(unit_name):
+    """
+    Determine if a unit is loaded
+    """
+    try:
+        value = get_unit_property(unit_name, "LoadState")
+        return value.lower() == "loaded"
+    except shellutil.CommandError:
+        return False

azurelinuxagent/ga/cgroupapi.py

@@ -59,7 +59,7 @@ class CGroupUtil(object):
     Cgroup utility methods which are independent of systemd cgroup api.
     """
     @staticmethod
-    def cgroups_supported():
+    def distro_supported():
         distro_info = get_distro()
         distro_name = distro_info[0]
         try:
@@ -650,8 +650,6 @@ def get_controllers(self, expected_relative_path=None):
                 controller = MemoryControllerV1(self._cgroup_name, controller_path)
 
             if controller is not None:
-                msg = "{0} controller for cgroup: {1}".format(supported_controller_name, controller)
-                log_cgroup_info(msg)
                 controllers.append(controller)
 
         return controllers
@@ -729,8 +727,6 @@ def get_controllers(self, expected_relative_path=None):
                 controller = MemoryControllerV2(self._cgroup_name, self._cgroup_path)
 
             if controller is not None:
-                msg = "{0} controller for cgroup: {1}".format(supported_controller_name, controller)
-                log_cgroup_info(msg)
                 controllers.append(controller)
 
         return controllers

azurelinuxagent/ga/cgroupcontroller.py

@@ -162,7 +162,7 @@ def is_active(self):
                                  ' Internal error: {1}'.format(self.path, ustr(e)))
         return False
 
-    def get_tracked_metrics(self, **_):
+    def get_tracked_metrics(self):
         """
         Retrieves the current value of the metrics tracked for this controller/cgroup and returns them as an array.
         """
@@ -173,3 +173,9 @@ def get_unit_properties(self):
         Returns a list of the unit properties to collect for the controller.
         """
         raise NotImplementedError()
+
+    def get_controller_type(self):
+        """
+        Returns the name of the controller.
+        """
+        raise NotImplementedError()

azurelinuxagent/ga/cgroupstelemetry.py

@@ -25,17 +25,8 @@ class CGroupsTelemetry(object):
     """
     """
     _tracked = {}
-    _track_throttled_time = False
     _rlock = threading.RLock()
 
-    @staticmethod
-    def set_track_throttled_time(value):
-        CGroupsTelemetry._track_throttled_time = value
-
-    @staticmethod
-    def get_track_throttled_time():
-        return CGroupsTelemetry._track_throttled_time
-
     @staticmethod
     def track_cgroup_controller(cgroup_controller):
         """
@@ -79,7 +70,7 @@ def poll_all_tracked():
         with CGroupsTelemetry._rlock:
             for controller in CGroupsTelemetry._tracked.values():
                 try:
-                    metrics.extend(controller.get_tracked_metrics(track_throttled_time=CGroupsTelemetry._track_throttled_time))
+                    metrics.extend(controller.get_tracked_metrics())
                 except Exception as e:
                     # There can be scenarios when the CGroup has been deleted by the time we are fetching the values
                     # from it. This would raise IOError with file entry not found (ERRNO: 2). We do not want to log
@@ -98,5 +89,4 @@ def poll_all_tracked():
     @staticmethod
     def reset():
         with CGroupsTelemetry._rlock:
-            CGroupsTelemetry._tracked.clear()  # emptying the dictionary
-            CGroupsTelemetry._track_throttled_time = False
+            CGroupsTelemetry._tracked.clear()  # emptying the dictionary

azurelinuxagent/ga/collect_logs.py

@@ -336,7 +336,7 @@ def get_max_recorded_metrics(self):
     def _poll_resource_usage(self):
         metrics = []
         for controller in self.controllers:
-            metrics.extend(controller.get_tracked_metrics(track_throttled_time=True))
+            metrics.extend(controller.get_tracked_metrics())
 
         for metric in metrics:
             current_max = self.max_recorded_metrics.get(metric.counter)

azurelinuxagent/ga/cpucontroller.py

@@ -108,24 +108,26 @@ def get_cpu_throttled_time(self, read_previous_throttled_time=True):
         """
         raise NotImplementedError()
 
-    def get_tracked_metrics(self, **kwargs):
+    def get_tracked_metrics(self):
         # Note: If the current cpu usage is less than the previous usage (metric is negative), then an empty array will
         # be returned and the agent won't track the metrics.
         tracked = []
         cpu_usage = self.get_cpu_usage()
         if cpu_usage >= float(0):
             tracked.append(MetricValue(MetricsCategory.CPU_CATEGORY, MetricsCounter.PROCESSOR_PERCENT_TIME, self.name, cpu_usage))
 
-        if 'track_throttled_time' in kwargs and kwargs['track_throttled_time']:
-            throttled_time = self.get_cpu_throttled_time()
-            if cpu_usage >= float(0) and throttled_time >= float(0):
-                tracked.append(MetricValue(MetricsCategory.CPU_CATEGORY, MetricsCounter.THROTTLED_TIME, self.name, throttled_time))
+        throttled_time = self.get_cpu_throttled_time()
+        if cpu_usage >= float(0) and throttled_time >= float(0):
+            tracked.append(MetricValue(MetricsCategory.CPU_CATEGORY, MetricsCounter.THROTTLED_TIME, self.name, throttled_time))
 
         return tracked
 
     def get_unit_properties(self):
         return ["CPUAccounting", "CPUQuotaPerSecUSec"]
 
+    def get_controller_type(self):
+        return "cpu"
+
 
 class CpuControllerV1(_CpuController):
     def initialize_cpu_usage(self):

azurelinuxagent/ga/exthandlers.py

@@ -1337,11 +1337,10 @@ def set_extension_resource_limits(self):
         # setup the resource limits for extension operations and it's services.
         man = self.load_manifest()
         resource_limits = man.get_resource_limits()
-        if not CGroupConfigurator.get_instance().is_extension_resource_limits_setup_completed(extension_name,
-                                                                                              cpu_quota=resource_limits.get_extension_slice_cpu_quota()):
-            CGroupConfigurator.get_instance().setup_extension_slice(
-                extension_name=extension_name, cpu_quota=resource_limits.get_extension_slice_cpu_quota())
-            CGroupConfigurator.get_instance().set_extension_services_cpu_memory_quota(resource_limits.get_service_list())
+
+        CGroupConfigurator.get_instance().setup_extension_slice(
+            extension_name=extension_name, cpu_quota=resource_limits.get_extension_slice_cpu_quota())
+        CGroupConfigurator.get_instance().set_extension_services_cpu_memory_quota(resource_limits.get_service_list())
 
     def create_status_file_if_not_exist(self, extension, status, code, operation, message):
         _, status_path = self.get_status_file_path(extension)
@@ -1476,7 +1475,7 @@ def uninstall(self, extension=None):
         resource_limits = man.get_resource_limits()
         CGroupConfigurator.get_instance().stop_tracking_extension_services_cgroups(
             resource_limits.get_service_list())
-        CGroupConfigurator.get_instance().remove_extension_services_drop_in_files(
+        CGroupConfigurator.get_instance().reset_extension_services_quota(
             resource_limits.get_service_list())
 
         uninstall_cmd = man.get_uninstall_command()
@@ -1502,8 +1501,9 @@ def on_rmtree_error(_, __, exc_info):
 
                 shutil.rmtree(base_dir, onerror=on_rmtree_error)
 
+            CGroupConfigurator.get_instance().stop_tracking_extension_cgroups(self.get_full_name())
             self.logger.info("Remove the extension slice: {0}".format(self.get_full_name()))
-            CGroupConfigurator.get_instance().remove_extension_slice(
+            CGroupConfigurator.get_instance().reset_extension_quota(
                 extension_name=self.get_full_name())
 
         except IOError as e:

azurelinuxagent/ga/memorycontroller.py

@@ -120,6 +120,9 @@ def get_tracked_metrics(self, **_):
     def get_unit_properties(self):
         return["MemoryAccounting"]
 
+    def get_controller_type(self):
+        return "memory"
+
 
 class MemoryControllerV1(_MemoryController):
     def get_memory_usage(self):

tests/ga/test_cgroupapi.py

@@ -83,7 +83,7 @@ def test_cgroups_should_be_supported_only_on_ubuntu16_centos7dot4_redhat7dot4_an
 
         for (distro, supported) in test_cases:
             with patch("azurelinuxagent.ga.cgroupapi.get_distro", return_value=distro):
-                self.assertEqual(CGroupUtil.cgroups_supported(), supported, "cgroups_supported() failed on {0}".format(distro))
+                self.assertEqual(CGroupUtil.distro_supported(), supported, "cgroups_supported() failed on {0}".format(distro))
 
 
 class SystemdCgroupsApiTestCase(AgentTestCase):