Cgroups api refactor for v2

azurelinuxagent/agent.py

@@ -28,9 +28,11 @@
 import subprocess
 import sys
 import threading
+
+from azurelinuxagent.common.exception import CGroupsException
 from azurelinuxagent.ga import logcollector, cgroupconfigurator
 from azurelinuxagent.ga.cgroup import AGENT_LOG_COLLECTOR, CpuCgroup, MemoryCgroup
-from azurelinuxagent.ga.cgroupapi import SystemdCgroupsApi
+from azurelinuxagent.ga.cgroupapi import get_cgroup_api, log_cgroup_warning
 
 import azurelinuxagent.common.conf as conf
 import azurelinuxagent.common.event as event
@@ -206,18 +208,29 @@ def collect_logs(self, is_full_mode):
 
         # Check the cgroups unit
         log_collector_monitor = None
-        cgroups_api = SystemdCgroupsApi()
-        cpu_cgroup_path, memory_cgroup_path = cgroups_api.get_process_cgroup_paths("self")
+        cpu_cgroup_path = None
+        memory_cgroup_path = None
         if CollectLogsHandler.is_enabled_monitor_cgroups_check():
-            cpu_slice_matches = (cgroupconfigurator.LOGCOLLECTOR_SLICE in cpu_cgroup_path)
-            memory_slice_matches = (cgroupconfigurator.LOGCOLLECTOR_SLICE in memory_cgroup_path)
+            try:
+                cgroup_api = get_cgroup_api()
+            except CGroupsException as e:
+                log_cgroup_warning("Unable to determine which cgroup version to use: {0}".format(ustr(e)), send_event=True)
+                sys.exit(logcollector.INVALID_CGROUPS_ERRCODE)
+
+            cpu_cgroup_path, memory_cgroup_path = cgroup_api.get_process_cgroup_paths("self")
+            cpu_slice_matches = False
+            memory_slice_matches = False
+            if cpu_cgroup_path is not None:
+                cpu_slice_matches = (cgroupconfigurator.LOGCOLLECTOR_SLICE in cpu_cgroup_path)
+            if memory_cgroup_path is not None:
+                memory_slice_matches = (cgroupconfigurator.LOGCOLLECTOR_SLICE in memory_cgroup_path)
 
             if not cpu_slice_matches or not memory_slice_matches:
-                logger.info("The Log Collector process is not in the proper cgroups:")
+                log_cgroup_warning("The Log Collector process is not in the proper cgroups:", send_event=False)
                 if not cpu_slice_matches:
-                    logger.info("\tunexpected cpu slice")
+                    log_cgroup_warning("\tunexpected cpu slice", send_event=False)
                 if not memory_slice_matches:
-                    logger.info("\tunexpected memory slice")
+                    log_cgroup_warning("\tunexpected memory slice", send_event=False)
 
                 sys.exit(logcollector.INVALID_CGROUPS_ERRCODE)
 

tests/data/cgroups/v2/proc_pid_cgroup

@@ -0,0 +1 @@
+0::/system.slice/Microsoft.A.Sample.Extension_1.0.1_aeac05dc-8c24-4542-95f2-a0d6be1c5ba7.scope

tests/data/cgroups/v2/proc_self_cgroup

@@ -0,0 +1 @@
+0::/system.slice/walinuxagent.service

tests/data/cgroups/v2/sys_fs_cgroup_cgroup.subtree_control

@@ -0,0 +1 @@
+cpuset cpu io memory pids

tests/ga/test_cgroupconfigurator_sudo.py

@@ -25,7 +25,7 @@
 from azurelinuxagent.ga.cgroupstelemetry import CGroupsTelemetry
 from azurelinuxagent.common.exception import ExtensionError, ExtensionErrorCodes
 from azurelinuxagent.common.future import ustr
-from tests.lib.mock_cgroup_environment import mock_cgroup_environment
+from tests.lib.mock_cgroup_environment import mock_cgroup_v1_environment
 from tests.lib.tools import AgentTestCase, patch, mock_sleep, i_am_root, is_python_version_26_or_34, skip_if_predicate_true
 
 
@@ -40,7 +40,7 @@ def _get_cgroup_configurator(self, initialize=True, enable=True, mock_commands=N
         CGroupConfigurator._instance = None
         configurator = CGroupConfigurator.get_instance()
         CGroupsTelemetry.reset()
-        with mock_cgroup_environment(self.tmp_dir) as mock_environment:
+        with mock_cgroup_v1_environment(self.tmp_dir) as mock_environment:
             if mock_commands is not None:
                 for command in mock_commands:
                     mock_environment.add_command(command)
@@ -139,7 +139,7 @@ def test_start_extension_command_should_not_use_fallback_option_if_extension_tim
             with tempfile.TemporaryFile(dir=self.tmp_dir, mode="w+b") as stderr:
                 with patch("azurelinuxagent.ga.extensionprocessutil.wait_for_process_completion_or_timeout",
                            return_value=[True, None, 0]):
-                    with patch("azurelinuxagent.ga.cgroupapi.SystemdCgroupsApi._is_systemd_failure",
+                    with patch("azurelinuxagent.ga.cgroupapi._SystemdCgroupApi._is_systemd_failure",
                                return_value=False):
                         with self.assertRaises(ExtensionError) as context_manager:
                             configurator.start_extension_command(

tests/ga/test_update.py

@@ -1955,7 +1955,7 @@ def iterator(*_, **__):
                         with patch('azurelinuxagent.ga.remoteaccess.get_remote_access_handler'):
                             with patch('azurelinuxagent.ga.agent_update_handler.get_agent_update_handler'):
                                 with patch('azurelinuxagent.ga.update.initialize_event_logger_vminfo_common_parameters'):
-                                    with patch('azurelinuxagent.ga.cgroupapi.CGroupsApi.cgroups_supported', return_value=False):  # skip all cgroup stuff
+                                    with patch('azurelinuxagent.ga.cgroupapi.CGroupUtil.cgroups_supported', return_value=False):  # skip all cgroup stuff
                                         with patch('azurelinuxagent.ga.update.is_log_collection_allowed', return_value=True):
                                             with patch('time.sleep'):
                                                 with patch('sys.exit'):

tests/lib/cgroups_tools.py

@@ -33,17 +33,3 @@ def create_legacy_agent_cgroup(cgroups_file_system_root, controller, daemon_pid)
         fileutil.append_file(os.path.join(legacy_cgroup, "cgroup.procs"), daemon_pid + "\n")
         return legacy_cgroup
 
-    @staticmethod
-    def create_agent_cgroup(cgroups_file_system_root, controller, extension_handler_pid):
-        """
-        Previous versions of the daemon (2.2.31-2.2.40) wrote their PID to /sys/fs/cgroup/{cpu,memory}/WALinuxAgent/WALinuxAgent;
-        starting from version 2.2.41 we track the agent service in walinuxagent.service instead of WALinuxAgent/WALinuxAgent.
-
-        This method creates a mock cgroup using the newer path and adds the given PID to it.
-        """
-        new_cgroup = os.path.join(cgroups_file_system_root, controller, "walinuxagent.service")
-        if not os.path.exists(new_cgroup):
-            os.makedirs(new_cgroup)
-        fileutil.append_file(os.path.join(new_cgroup, "cgroup.procs"), extension_handler_pid + "\n")
-        return new_cgroup
-

tests/lib/mock_cgroup_environment.py

@@ -20,29 +20,11 @@
 from tests.lib.tools import patch, data_dir
 from tests.lib.mock_environment import MockEnvironment, MockCommand
 
-_MOCKED_COMMANDS = [
+# Mocked commands which are common between v1, v2, and hybrid cgroup environments
+_MOCKED_COMMANDS_COMMON = [
    MockCommand(r"^systemctl --version$",
 '''systemd 237
 +PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN -PCRE2 default-hierarchy=hybrid
-'''),
-
-    MockCommand(r"^mount -t cgroup$",
-'''cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)
-cgroup on /sys/fs/cgroup/rdma type cgroup (rw,nosuid,nodev,noexec,relatime,rdma)
-cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
-cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
-cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
-cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
-cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
-cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
-cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
-cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
-cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
-cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
-'''),
-
-    MockCommand(r"^mount -t cgroup2$",
-'''cgroup on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime) 
 '''),
 
     MockCommand(r"^systemctl show walinuxagent\.service --property Slice",
@@ -77,10 +59,84 @@
 
 ]
 
-_MOCKED_FILES = [
-    ("/proc/self/cgroup", os.path.join(data_dir, 'cgroups', 'proc_self_cgroup')),
-    (r"/proc/[0-9]+/cgroup", os.path.join(data_dir, 'cgroups', 'proc_pid_cgroup')),
-    ("/sys/fs/cgroup/unified/cgroup.controllers", os.path.join(data_dir, 'cgroups', 'sys_fs_cgroup_unified_cgroup.controllers'))
+_MOCKED_COMMANDS_V1 = [
+    MockCommand(r"^findmnt -t cgroup --noheadings$",
+'''/sys/fs/cgroup/systemd          cgroup cgroup rw,nosuid,nodev,noexec,relatime,xattr,name=systemd
+/sys/fs/cgroup/devices          cgroup cgroup rw,nosuid,nodev,noexec,relatime,devices
+/sys/fs/cgroup/rdma             cgroup cgroup rw,nosuid,nodev,noexec,relatime,rdma
+/sys/fs/cgroup/perf_event       cgroup cgroup rw,nosuid,nodev,noexec,relatime,perf_event
+/sys/fs/cgroup/net_cls,net_prio cgroup cgroup rw,nosuid,nodev,noexec,relatime,net_cls,net_prio
+/sys/fs/cgroup/blkio            cgroup cgroup rw,nosuid,nodev,noexec,relatime,blkio
+/sys/fs/cgroup/cpuset           cgroup cgroup rw,nosuid,nodev,noexec,relatime,cpuset
+/sys/fs/cgroup/misc             cgroup cgroup rw,nosuid,nodev,noexec,relatime,misc
+/sys/fs/cgroup/cpu,cpuacct      cgroup cgroup rw,nosuid,nodev,noexec,relatime,cpu,cpuacct
+/sys/fs/cgroup/memory           cgroup cgroup rw,nosuid,nodev,noexec,relatime,memory
+/sys/fs/cgroup/freezer          cgroup cgroup rw,nosuid,nodev,noexec,relatime,freezer
+/sys/fs/cgroup/hugetlb          cgroup cgroup rw,nosuid,nodev,noexec,relatime,hugetlb
+/sys/fs/cgroup/pids             cgroup cgroup rw,nosuid,nodev,noexec,relatime,pids
+'''),
+
+    MockCommand(r"^findmnt -t cgroup2 --noheadings$", ''),
+
+    MockCommand(r"^stat -f --format=%T /sys/fs/cgroup$", 'tmpfs'),
+
+]
+
+_MOCKED_COMMANDS_V2 = [
+    MockCommand(r"^findmnt -t cgroup2 --noheadings$",
+'''/sys/fs/cgroup cgroup2 cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot
+'''),
+
+    MockCommand(r"^findmnt -t cgroup --noheadings$", ''),
+
+    MockCommand(r"^stat -f --format=%T /sys/fs/cgroup$", 'cgroup2fs'),
+
+]
+
+_MOCKED_COMMANDS_HYBRID = [
+    MockCommand(r"^findmnt -t cgroup --noheadings$",
+'''/sys/fs/cgroup/systemd          cgroup cgroup rw,nosuid,nodev,noexec,relatime,xattr,name=systemd
+/sys/fs/cgroup/devices          cgroup cgroup rw,nosuid,nodev,noexec,relatime,devices
+/sys/fs/cgroup/rdma             cgroup cgroup rw,nosuid,nodev,noexec,relatime,rdma
+/sys/fs/cgroup/perf_event       cgroup cgroup rw,nosuid,nodev,noexec,relatime,perf_event
+/sys/fs/cgroup/net_cls,net_prio cgroup cgroup rw,nosuid,nodev,noexec,relatime,net_cls,net_prio
+/sys/fs/cgroup/blkio            cgroup cgroup rw,nosuid,nodev,noexec,relatime,blkio
+/sys/fs/cgroup/cpuset           cgroup cgroup rw,nosuid,nodev,noexec,relatime,cpuset
+/sys/fs/cgroup/misc             cgroup cgroup rw,nosuid,nodev,noexec,relatime,misc
+/sys/fs/cgroup/cpu,cpuacct      cgroup cgroup rw,nosuid,nodev,noexec,relatime,cpu,cpuacct
+/sys/fs/cgroup/memory           cgroup cgroup rw,nosuid,nodev,noexec,relatime,memory
+/sys/fs/cgroup/freezer          cgroup cgroup rw,nosuid,nodev,noexec,relatime,freezer
+/sys/fs/cgroup/hugetlb          cgroup cgroup rw,nosuid,nodev,noexec,relatime,hugetlb
+/sys/fs/cgroup/pids             cgroup cgroup rw,nosuid,nodev,noexec,relatime,pids
+'''),
+
+    MockCommand(r"^findmnt -t cgroup2 --noheadings$",
+'''/sys/fs/cgroup/unified cgroup2 cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate
+'''),
+
+    MockCommand(r"^stat -f --format=%T /sys/fs/cgroup$", 'tmpfs'),
+
+    MockCommand(r"^stat -f --format=%T /sys/fs/cgroup/unified$", 'cgroup2fs'),
+
+]
+
+_MOCKED_FILES_V1 = [
+    ("/proc/self/cgroup", os.path.join(data_dir, 'cgroups', 'v1', 'proc_self_cgroup')),
+    (r"/proc/[0-9]+/cgroup", os.path.join(data_dir, 'cgroups', 'v1', 'proc_pid_cgroup'))
+]
+
+_MOCKED_FILES_V2 = [
+    ("/proc/self/cgroup", os.path.join(data_dir, 'cgroups', 'v2', 'proc_self_cgroup')),
+    (r"/proc/[0-9]+/cgroup", os.path.join(data_dir, 'cgroups', 'v2', 'proc_pid_cgroup')),
+    ("/sys/fs/cgroup/cgroup.subtree_control", os.path.join(data_dir, 'cgroups', 'v2', 'sys_fs_cgroup_cgroup.subtree_control')),
+    ("/sys/fs/cgroup/azure.slice/cgroup.subtree_control", os.path.join(data_dir, 'cgroups', 'v2', 'sys_fs_cgroup_cgroup.subtree_control')),
+    ("/sys/fs/cgroup/azure.slice/walinuxagent.service/cgroup.subtree_control", os.path.join(data_dir, 'cgroups', 'v2', 'sys_fs_cgroup_cgroup.subtree_control_empty'))
+]
+
+_MOCKED_FILES_HYBRID = [
+    ("/proc/self/cgroup", os.path.join(data_dir, 'cgroups', 'v1', 'proc_self_cgroup')),
+    (r"/proc/[0-9]+/cgroup", os.path.join(data_dir, 'cgroups', 'v1', 'proc_pid_cgroup')),
+    ("/sys/fs/cgroup/unified/cgroup.controllers", os.path.join(data_dir, 'cgroups', 'hybrid', 'sys_fs_cgroup_cgroup.controllers'))
 ]
 
 _MOCKED_PATHS = [
@@ -106,18 +162,56 @@ class UnitFilePaths:
 
 
 @contextlib.contextmanager
-def mock_cgroup_environment(tmp_dir):
+def mock_cgroup_v1_environment(tmp_dir):
+    """
+    Creates a mock environment for cgroup v1 hierarchy used by the tests related to cgroups (currently it only
+    provides support for systemd platforms).
+    The command output used in __MOCKED_COMMANDS comes from an Ubuntu 20 system.
+    """
+    data_files = [
+        (os.path.join(data_dir, 'init', 'walinuxagent.service'), UnitFilePaths.walinuxagent),
+        (os.path.join(data_dir, 'init', 'azure.slice'), UnitFilePaths.azure),
+        (os.path.join(data_dir, 'init', 'azure-vmextensions.slice'), UnitFilePaths.vmextensions)
+    ]
+
+    with patch('azurelinuxagent.ga.cgroupapi.CGroupUtil.cgroups_supported', return_value=True):
+        with patch('azurelinuxagent.common.osutil.systemd.is_systemd', return_value=True):
+            with MockEnvironment(tmp_dir, commands=_MOCKED_COMMANDS_COMMON + _MOCKED_COMMANDS_V1, paths=_MOCKED_PATHS, files=_MOCKED_FILES_V1, data_files=data_files) as mock:
+                yield mock
+
+
+@contextlib.contextmanager
+def mock_cgroup_v2_environment(tmp_dir):
+    """
+    Creates a mock environment for cgroup v2 hierarchy used by the tests related to cgroups (currently it only
+    provides support for systemd platforms).
+    The command output used in __MOCKED_COMMANDS comes from an Ubuntu 22 system.
+    """
+    data_files = [
+        (os.path.join(data_dir, 'init', 'walinuxagent.service'), UnitFilePaths.walinuxagent),
+        (os.path.join(data_dir, 'init', 'azure.slice'), UnitFilePaths.azure),
+        (os.path.join(data_dir, 'init', 'azure-vmextensions.slice'), UnitFilePaths.vmextensions)
+    ]
+
+    with patch('azurelinuxagent.ga.cgroupapi.CGroupUtil.cgroups_supported', return_value=True):
+        with patch('azurelinuxagent.common.osutil.systemd.is_systemd', return_value=True):
+            with MockEnvironment(tmp_dir, commands=_MOCKED_COMMANDS_COMMON + _MOCKED_COMMANDS_V2, paths=_MOCKED_PATHS, files=_MOCKED_FILES_V2, data_files=data_files) as mock:
+                yield mock
+
+
+@contextlib.contextmanager
+def mock_cgroup_hybrid_environment(tmp_dir):
+    """
+    Creates a mock environment for cgroup hybrid hierarchy used by the tests related to cgroups (currently it only
+    provides support for systemd platforms).
     """
-    Creates a mocks environment used by the tests related to cgroups (currently it only provides support for systemd platforms).
-    The command output used in __MOCKED_COMMANDS comes from an Ubuntu 18 system.
-   """
     data_files = [
         (os.path.join(data_dir, 'init', 'walinuxagent.service'), UnitFilePaths.walinuxagent),
         (os.path.join(data_dir, 'init', 'azure.slice'), UnitFilePaths.azure),
         (os.path.join(data_dir, 'init', 'azure-vmextensions.slice'), UnitFilePaths.vmextensions)
     ]
 
-    with patch('azurelinuxagent.ga.cgroupapi.CGroupsApi.cgroups_supported', return_value=True):
+    with patch('azurelinuxagent.ga.cgroupapi.CGroupUtil.cgroups_supported', return_value=True):
         with patch('azurelinuxagent.common.osutil.systemd.is_systemd', return_value=True):
-            with MockEnvironment(tmp_dir, commands=_MOCKED_COMMANDS, paths=_MOCKED_PATHS, files=_MOCKED_FILES, data_files=data_files) as mock:
+            with MockEnvironment(tmp_dir, commands=_MOCKED_COMMANDS_COMMON + _MOCKED_COMMANDS_HYBRID, paths=_MOCKED_PATHS, files=_MOCKED_FILES_HYBRID, data_files=data_files) as mock:
                 yield mock