def discover_instances(self):
config = self._config
discovery_interval = config.instance.get('discovery_interval', 3600)
while self._running:
start_time = time.time()
for host in config.ip_network.hosts():
host = str(host)
if host in config.discovered_instances:
continue
instance = config.instance.copy()
instance.pop('network_address')
instance['ip_address'] = host
host_config = self._build_config(instance)
try:
sys_object_oid = self.fetch_sysobject_oid(host_config)
except Exception as e:
self.log.debug("Error scanning host %s: %s", host, e)
continue
if sys_object_oid not in self.profiles_by_oid:
if not (host_config.table_oids or host_config.raw_oids):
self.log.warn("Host %s didn't match a profile for sysObjectID %s", host, sys_object_oid)
continue
else:
profile = self.profiles_by_oid[sys_object_oid]
host_config.refresh_with_profile(self.profiles[profile], self.warning, self.log)
config.discovered_instances[host] = host_config
write_persistent_cache(self.check_id, json.dumps(list(config.discovered_instances)))
time_elapsed = time.time() - start_time
if discovery_interval - time_elapsed > 0:
time.sleep(discovery_interval - time_elapsed)
def write_persistent_cache(self, key, value):
# type: (str, str) -> None
"""Stores `value` in a persistent cache for this check instance.
The cache is located in a path where the agent is guaranteed to have read & write permissions. Namely in
- `%ProgramData%\\Datadog\\run` on Windows.
- `/opt/datadog-agent/run` everywhere else.
The cache is persistent between agent restarts but will be rebuilt if the check instance configuration changes.
- **key** (_str_) - Identifier used to build the filename
- **value** (_str_) - Value to store
"""
datadog_agent.write_persistent_cache(self._persistent_cache_id(key), value)
def _start_discovery(self):
cache = read_persistent_cache(self.check_id)
if cache:
hosts = json.loads(cache)
for host in hosts:
try:
ipaddress.ip_address(host)
except ValueError:
write_persistent_cache(self.check_id, json.dumps([]))
break
instance = self.instance.copy()
instance.pop('network_address')
instance['ip_address'] = host
host_config = self._build_config(instance)
self._config.discovered_instances[host] = host_config
self._thread = threading.Thread(target=self.discover_instances, name=self.name)
self._thread.daemon = True
self._thread.start()
def write_persistent_cache(self, key, value):
# type: (str, str) -> None
datadog_agent.write_persistent_cache(self._persistent_cache_id(key),
value)
