etcd3_wrapper/etcd_wrapper.py

72 lines
2.2 KiB
Python

import etcd3
import json
import signal
from dataclasses import dataclass
from collections import namedtuple
PseudoEtcdMeta = namedtuple("PseudoEtcdMeta", ["key"])
@dataclass(init=False)
class EtcdEntry:
def __init__(self, meta, value, value_in_json=False):
self.key = meta.key.decode("utf-8")
self.value = value.decode("utf-8")
if value_in_json:
self.value = json.loads(self.value)
key: str
value: str
class Etcd3Wrapper(object):
def __init__(self, *args, **kwargs):
self.client = etcd3.client(*args, **kwargs)
def get(self, *args, value_in_json=False, **kwargs):
_value, _key = self.client.get(*args, **kwargs)
if _key is None:
return None
return EtcdEntry(_key, _value, value_in_json=value_in_json)
def put(self, *args, value_in_json=False, **kwargs):
_key, _value = args
if value_in_json:
_value = json.dumps(_value)
if not isinstance(_key, str):
_key = _key.decode("utf-8")
return self.client.put(_key, _value, **kwargs)
def get_prefix(self, *args, value_in_json=False, **kwargs):
r = self.client.get_prefix(*args, **kwargs)
for entry in r:
yield EtcdEntry(*entry[::-1], value_in_json=value_in_json)
def watch_prefix(self, *args, timeout=0, value_in_json=False, **kwargs):
if timeout > 0:
signal.signal(signal.SIGALRM, raise_timeout)
while True:
try:
if timeout > 0:
signal.alarm(timeout)
r, _ = self.client.watch_prefix(*args, **kwargs)
for event in r:
# if e.value is None don't propagate its value
if event.value is None:
continue
event = EtcdEntry(event, event.value, value_in_json=value_in_json)
yield event
except TimeoutError:
_value = {"status": "TIMEOUT"}
yield EtcdEntry(PseudoEtcdMeta(key=b"TIMEOUT"), value=str.encode(json.dumps(_value)))
def raise_timeout(signum, frame):
_ = signum, frame
raise TimeoutError()