def read_persistent_cache(self, key):
# type: (str) -> str
"""Returns the value previously stored with `write_persistent_cache` for the same `key`.
- **key** (_str_) - The key to retrieve
"""
return datadog_agent.read_persistent_cache(self._persistent_cache_id(key))
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 read_persistent_cache(self, key):
# type: (str) -> str
return datadog_agent.read_persistent_cache(
self._persistent_cache_id(key))