def test_create_should_return_a_FileSystemCgroupsApi_on_non_systemd_platforms(
self):
with patch("azurelinuxagent.common.cgroupapi.CGroupsApi._is_systemd",
return_value=False):
api = CGroupsApi.create()
self.assertTrue(type(api) == FileSystemCgroupsApi)
def __init__(self):
"""
Ensures the cgroups file system is mounted and selects the correct API to interact with it
"""
osutil = get_osutil()
self._cgroups_supported = osutil.is_cgroups_supported()
if self._cgroups_supported:
self._enabled = True
try:
osutil.mount_cgroups()
self._cgroups_api = CGroupsApi.create()
status = "The cgroup filesystem is ready to use"
except Exception as e:
status = ustr(e)
self._enabled = False
else:
self._enabled = False
self._cgroups_api = None
status = "Cgroups are not supported by the platform"
logger.info("CGroups Status: {0}".format(status))
add_event(AGENT_NAME,
version=CURRENT_VERSION,
op=WALAEventOperation.InitializeCGroups,
is_success=self._enabled,
message=status,
log_event=False)
def initialize(self):
try:
if self._initialized:
return
#
# check whether cgroup monitoring is supported on the current distro
#
self._cgroups_supported = CGroupsApi.cgroups_supported()
if not self._cgroups_supported:
logger.info("Cgroup monitoring is not supported on {0}",
get_distro())
return
#
# check systemd
#
self._cgroups_api = CGroupsApi.create()
if not isinstance(self._cgroups_api, SystemdCgroupsApi):
message = "systemd was not detected on {0}".format(
get_distro())
logger.warn(message)
add_event(op=WALAEventOperation.CGroupsInitialize,
is_success=False,
message=message,
log_event=False)
return
def log_cgroup_info(format_string, *args):
message = format_string.format(*args)
logger.info(message)
add_event(op=WALAEventOperation.CGroupsInfo,
message=message)
def log_cgroup_warn(format_string, *args):
message = format_string.format(*args)
logger.warn(message)
add_event(op=WALAEventOperation.CGroupsInfo,
message=message,
is_success=False,
log_event=False)
log_cgroup_info("systemd version: {0}",
self._cgroups_api.get_systemd_version())
#
# Older versions of the daemon (2.2.31-2.2.40) wrote their PID to /sys/fs/cgroup/{cpu,memory}/WALinuxAgent/WALinuxAgent. When running
# under systemd this could produce invalid resource usage data. Do not enable cgroups under this condition.
#
legacy_cgroups = self._cgroups_api.cleanup_legacy_cgroups()
if legacy_cgroups > 0:
log_cgroup_warn(
"The daemon's PID was added to a legacy cgroup; will not monitor resource usage."
)
return
#
# check v1 controllers
#
cpu_controller_root, memory_controller_root = self._cgroups_api.get_cgroup_mount_points(
)
if cpu_controller_root is not None:
logger.info("The CPU cgroup controller is mounted at {0}",
cpu_controller_root)
else:
log_cgroup_warn("The CPU cgroup controller is not mounted")
if memory_controller_root is not None:
logger.info(
"The memory cgroup controller is mounted at {0}",
memory_controller_root)
else:
log_cgroup_warn(
"The memory cgroup controller is not mounted")
#
# check v2 controllers
#
cgroup2_mountpoint, cgroup2_controllers = self._cgroups_api.get_cgroup2_controllers(
)
if cgroup2_mountpoint is not None:
log_cgroup_warn(
"cgroups v2 mounted at {0}. Controllers: [{1}]",
cgroup2_mountpoint, cgroup2_controllers)
#
# check the cgroups for the agent
#
agent_unit_name = self._cgroups_api.get_agent_unit_name()
cpu_cgroup_relative_path, memory_cgroup_relative_path = self._cgroups_api.get_process_cgroup_relative_paths(
"self")
if cpu_cgroup_relative_path is None:
log_cgroup_warn(
"The agent's process is not within a CPU cgroup")
else:
cpu_accounting = self._cgroups_api.get_unit_property(
agent_unit_name, "CPUAccounting")
log_cgroup_info('CPUAccounting: {0}', cpu_accounting)
if memory_cgroup_relative_path is None:
log_cgroup_warn(
"The agent's process is not within a memory cgroup")
else:
memory_accounting = self._cgroups_api.get_unit_property(
agent_unit_name, "MemoryAccounting")
log_cgroup_info('MemoryAccounting: {0}', memory_accounting)
#
# All good, enable cgroups and start monitoring the agent
#
self._cgroups_enabled = True
if cpu_controller_root is None or cpu_cgroup_relative_path is None:
logger.info("Will not track CPU for the agent's cgroup")
else:
self._agent_cpu_cgroup_path = os.path.join(
cpu_controller_root, cpu_cgroup_relative_path)
CGroupsTelemetry.track_cgroup(
CpuCgroup(agent_unit_name,
self._agent_cpu_cgroup_path))
if memory_controller_root is None or memory_cgroup_relative_path is None:
logger.info("Will not track memory for the agent's cgroup")
else:
self._agent_memory_cgroup_path = os.path.join(
memory_controller_root, memory_cgroup_relative_path)
CGroupsTelemetry.track_cgroup(
MemoryCgroup(agent_unit_name,
self._agent_memory_cgroup_path))
log_cgroup_info("Agent cgroups: CPU: {0} -- MEMORY: {1}",
self._agent_cpu_cgroup_path,
self._agent_memory_cgroup_path)
except Exception as e:
message = "Error initializing cgroups: {0}".format(ustr(e))
logger.warn(message)
add_event(op=WALAEventOperation.CGroupsInitialize,
is_success=False,
message=message,
log_event=False)
finally:
self._initialized = True