import json import etcd3 as etcd3 CLUSTER_INFO_KEY = '/syncthing_monitor/cluster_info' class EtcdClient: def __init__(self, host, port, key=CLUSTER_INFO_KEY): self.etcd = etcd3.client(host=host, port=port) self.key = key def load_cluster_info(self): print("Retrieving cluster info from etcd...", flush=True) raw_value = self.etcd.get(self.key)[0] if raw_value is None: return {'devices': []} return json.loads(raw_value) def add_device_to_cluster(self, device_id, node_name, address): with self.etcd.lock('syncthing_monitor'): cluster_info = self.load_cluster_info() if any(device_id in device['id'] for device in cluster_info['devices']): return new_device = { 'id': device_id, 'node_name': node_name, 'address': address } cluster_info['devices'].append(new_device) print("Updating etcd value for '{0}': {1}".format(self.key, json.dumps(cluster_info)), flush=True) self.etcd.put(self.key, json.dumps(cluster_info)) def get_device_list(self): device_list = self.load_cluster_info()['devices'] print("Obtained device_list devices from etcd: {0}".format(json.dumps(device_list)), flush=True) return device_list def register_device_update_handler(self, device_update_handler): self.etcd.add_watch_callback(self.key, device_update_handler)