JarCastingjetcd: Java binding for etcd
TravisCI:
CircleCI:
A simple Java client library for the awesome etcd
Uses the Apache HttpAsyncClient to implement watches without blocking a thread, and Google's Guava to give us the nice ListenableFuture interface.
Check out SmokeTest.java to see how this is used (and tested), but here's a quick code example:
EtcdClient client = new EtcdClient(URI.create("http://127.0.0.1:4001/"));
String key = "/watch";
EtcdResult result = this.client.set(key, "hello");
Assert.assertEquals("hello", result.value);
result = this.client.get(key);
Assert.assertEquals("hello", result.value);
ListenableFuture<EtcdResult> watchFuture = this.client.watch(key, result.index + 1);
Assert.assertFalse(watchFuture.isDone());
result = this.client.set(key, "world");
Assert.assertEquals("world", result.value);
EtcdResult watchResult = watchFuture.get(100, TimeUnit.MILLISECONDS);
Assert.assertNotNull(result);
Assert.assertEquals("world", result.value);
For a bit of background, check out the blog post.
Testing
-
Export the IP for the node to use (this example is the typical IP of a
docker-machinehost:export HOST_IP="192.168.99.100" -
Fire up an
etcdDocker container:
docker run -d -p 4001:4001 -p 2380:2380 -p 2379:2379 --name etcd quay.io/coreos/etcd:v2.0.3
-name etcd0
-advertise-client-urls http://${HOST_IP}:2379,http://${HOST_IP}:4001
-listen-client-urls http://0.0.0.0:2379,http://0.0.0.0:4001
-initial-advertise-peer-urls http://${HOST_IP}:2380
-listen-peer-urls http://0.0.0.0:2380
-initial-cluster-token etcd-cluster-1
-initial-cluster etcd0=http://${HOST_IP}:2380
-initial-cluster-state new ```