aio_etcd 0.4.6.1

先决条件

此版本的python etcd只能与etcd服务器版本2.0.x或更高版本一起正常工作。如果您运行的是较旧版本的etcd，请使用python etcd 0.3.3或更早版本。

众所周知，这个客户机使用Python3.5由于使用了“async def”语法，它在旧版本的python中不起作用。

不支持Python2。

来源

$ python setup.py install

创建客户端对象

importaio_etcdasetcdclient=etcd.Client()# this will create a client against etcd server running on localhost on port 4001client=etcd.Client(port=4002)client=etcd.Client(host='127.0.0.1',port=4003)client=etcd.Client(host=(('127.0.0.1',4001),('127.0.0.1',4002),('127.0.0.1',4003)))client=etcd.Client(host='127.0.0.1',port=4003,allow_redirect=False)# wont let you run sensitive commands on non-leader machines, default is true# If you have defined a SRV record for _etcd._tcp.example.com pointing to the clientsclient=etcd.Client(srv_domain='example.com',protocol="https")# create a client against https://api.example.com:443/etcdclient=etcd.Client(host='api.example.com',protocol='https',port=443,version_prefix='/etcd')

写一个键

awaitclient.write('/nodes/n1',1)# with ttlawaitclient.set('/nodes/n1',1)# Equivalent, for compatibility reasons.awaitclient.write('/nodes/n2',2,ttl=4)# sets the ttl to 4 seconds

读取键

(awaitclient.read('/nodes/n2')).value# read a value(awaitclient.get('/nodes/n2')).value# Equivalent, for compatibility reasons.awaitclient.read('/nodes',recursive=True)# get all the values of a directory, recursively.# raises etcd.EtcdKeyNotFound when key not foundtry:client.read('/invalid/path')exceptetcd.EtcdKeyNotFound:# do somethingprint"error"

删除键

awaitclient.delete('/nodes/n1')

原子比较和交换

awaitclient.write('/nodes/n2',2,prevValue=4)# will set /nodes/n2 's value to 2 only if its previous value was 4awaitclient.write('/nodes/n2',2,prevExist=False)# will set /nodes/n2 's value to 2 only if the key did not exist beforeawaitclient.write('/nodes/n2',2,prevIndex=30)# will set /nodes/n2 's value to 2 only if the key was last modified at index 30awaitclient.test_and_set('/nodes/n2',2,4)#equivalent to client.write('/nodes/n2', 2, prevValue = 4)

您还可以原子更新结果：

awaitclient.write('/foo','bar')result=awaitclient.read('/foo')print(result.value)# barresult.value+=u'bar'updated=awaitclient.update(result)# if any other client wrote to '/foo' in the meantime this will failprint(updated.value)# barbar

看一把钥匙

result=awaitclient.read('/nodes/n1')# start from a known initial valueresult=awaitclient.read('/nodes/n1',wait=True,waitIndex=result.modifiedIndex+1)# will wait till the key is changed, and return once it's changedresult=awaitclient.read('/nodes/n1',wait=True,waitIndex=10)# get all changes on this key starting from index 10result=awaitclient.watch('/nodes/n1')# equivalent to client.read('/nodes/n1', wait = True)result=awaitclient.watch('/nodes/n1',index=result.modifiedIndex+1)

如果要超时read（）调用，请将其包装在异步中。等待：

result=awaitasyncio.wait_for(client.read('/nodes/n1',wait=True),timeout=30)

刷新按键ttl

（因为etcd 2.3.0）可以在不通知当前观察者的情况下刷新etcd中的键

这可以通过在更新ttl时将refresh设置为true来实现。

刷新密钥时不能更新其值

client.write('/nodes/n1','value',ttl=30)# sets the ttl to 30 secondsclient.refresh('/nodes/n1',ttl=600)# refresh ttl to 600 seconds, without notifying current watchers

锁定模块

# Initialize the lock object:# NOTE: this does not acquire a lockfromaio_etcd.lockimportLockclient=etcd.Client()# Or you can custom lock prefix, default is '/_locks/' if you are using HEADclient=etcd.Client(lock_prefix='/my_etcd_root/_locks')lock=etcd.Lock(client,'my_lock_name')# Use the lock object:awaitlock.acquire(blocking=True,# will block until the lock is acquiredlock_ttl=None)# lock will live until we release itlock.is_acquired# Trueawaitlock.acquire(lock_ttl=60)# renew a lockawaitlock.release()# release an existing locklock.is_acquired# False# The lock object may also be used as a context manager:asyncwithLock(client,'customer1')asmy_lock:do_stuff()my_lock.is_acquired# Trueawaitmy_lock.acquire(lock_ttl=60)my_lock.is_acquired# False

获取群集中的计算机

machines=awaitclient.machines()

获得集群的领导者

leaderinfo=awaitclient.leader()

在目录中生成顺序键

x=awaitclient.write("/dir/name","value",append=True)print("generated key: "+x.key)# actually the whole pathprint("stored value: "+x.value)

列出目录的内容

#stick a couple values in the directoryawaitclient.write("/dir/name","value1",append=True)awaitclient.write("/dir/name","value2",append=True)directory=awaitclient.get("/dir/name")# loop through a directory's childrenforresultindirectory.children:print(result.key+": "+result.value)# or just get the first child valueprint(directory.next(children).value)