static async Task DoSample()
{
EtcdClientOpitions options = new EtcdClientOpitions() {
Urls = new string[] { "https://etcd0.em", "https://etcd1.em", "https://etcd2.em" },
Username = "******",
Password = "******",
UseProxy = false,
IgnoreCertificateError = true, // If the ectd server is running with self-signed SSL certificate and we can ignore the SSL error
//X509Certificate = new X509Certificate2(@"client.p12"), // client cerificate
JsonDeserializer = new NewtonsoftJsonDeserializer(),
};
EtcdClient etcdClient = new EtcdClient(options);
string key = "/my/key";
string value;
// query the value of the node using GetNodeValueAsync
try {
value = await etcdClient.GetNodeValueAsync(key);
Console.WriteLine("The value of `{0}` is `{1}`", key, value);
}
catch(EtcdCommonException.KeyNotFound) {
Console.WriteLine("Key `{0}` does not exist", key);
}
// update the value using SetNodeAsync
EtcdResponse resp = await etcdClient.SetNodeAsync(key, "some value");
Console.WriteLine("Key `{0}` is changed, modifiedIndex={1}", key, resp.Node.ModifiedIndex);
// query the node using GetNodeAsync
resp = await etcdClient.GetNodeAsync(key, ignoreKeyNotFoundException: true);
if (resp == null || resp.Node == null)
Console.WriteLine("Key `{0}` does not exist", key);
else
Console.WriteLine("The value of `{0}` is `{1}`", key, resp.Node.Value);
//////////////////////////////////////////////////////////
List<Task<EtcdResponse>> tasks = new List<Task<EtcdResponse>>();
key = "/in-order-queue";
// start monitoring the expire event
WatchChanges(etcdClient, key);
// create 5 in-order nodes, TTL = 3 second
for (int i = 0; i < 5; i++) {
tasks.Add( etcdClient.CreateInOrderNodeAsync(key, i.ToString(), ttl: 3) );
}
await Task.WhenAll(tasks);
// list the in-order nodes
resp = await etcdClient.GetNodeAsync(key, false, recursive: true, sorted:true);
if (resp.Node.Nodes != null) {
foreach (var node in resp.Node.Nodes)
{
Console.WriteLine("`{0}` = {1}", node.Key, node.Value);
}
}
/////////////////////////////////////////////////////////////
key = "/my/cas-test";
value = Guid.NewGuid().ToString();
try {
resp = await etcdClient.CreateNodeAsync(key, value, null, dir : false);
Console.WriteLine("Key `{0}` is created with value {1}", key, value);
}
catch (EtcdCommonException.NodeExist) {
Console.WriteLine("Key `{0}` already exists", key);
}
long prevIndex = 1;
try {
resp = await etcdClient.CompareAndSwapNodeAsync(key, value, "new value");
Console.WriteLine("Key `{0}` is updated to `{1}`", key, resp.Node.Value);
prevIndex = resp.Node.ModifiedIndex;
}
catch (EtcdCommonException.KeyNotFound) {
Console.WriteLine("Key `{0}` does not exists", key);
}
catch (EtcdCommonException.TestFailed) {
Console.WriteLine("Key `{0}` can not be updated because the supplied previous value is incorrect", key);
}
try {
resp = await etcdClient.CompareAndSwapNodeAsync(key, prevIndex, "new value2");
Console.WriteLine("Key `{0}` is updated to `{1}`", key, resp.Node.Value);
}
catch (EtcdCommonException.KeyNotFound) {
Console.WriteLine("Key `{0}` does not exists", key);
}
catch (EtcdCommonException.TestFailed) {
Console.WriteLine("Key `{0}` can not be updated because the supplied previous index is incorrect", key);
}
try {
resp = await etcdClient.CompareAndDeleteNodeAsync(key, prevIndex+1);
Console.WriteLine("Key `{0}` is deleted", key);
}
catch (EtcdCommonException.KeyNotFound) {
Console.WriteLine("Key `{0}` does not exists", key);
}
catch (EtcdCommonException.TestFailed) {
Console.WriteLine("Key `{0}` can not be deleted because the supplied previous index is incorrect", key);
}
if (prevIndex == 1) // the previous CAS failed
{
try {
resp = await etcdClient.CompareAndDeleteNodeAsync(key, "new value2");
Console.WriteLine("Key `{0}` is deleted", key);
}
catch (EtcdCommonException.KeyNotFound) {
Console.WriteLine("Key `{0}` does not exists", key);
}
catch (EtcdCommonException.TestFailed) {
Console.WriteLine("Key `{0}` can not be deleted because the supplied previous value is incorrect", key);
etcdClient.DeleteNodeAsync(key, ignoreKeyNotFoundException: true).Wait();
}
}
}
static async void WatchChanges(EtcdClient etcdClient, string key)
{
long waitIndex = etcdClient.LastIndex;
for (; ; )
{
try
{
EtcdResponse resp = await etcdClient.WatchNodeAsync(key, recursive: true, waitIndex: waitIndex);
if (resp != null && resp.Node != null)
{
if( string.Equals( resp.Action, EtcdResponse.ACTION_EXPIRE) )
Console.WriteLine("`{0}` is expired", resp.Node.Key);
waitIndex = resp.Node.ModifiedIndex + 1;
}
continue;
}
catch(EtcdException.EventIndexCleared)
{
waitIndex = etcdClient.LastIndex;
}
catch(EtcdException.WatcherCleared)
{
waitIndex = etcdClient.LastIndex;
}
catch(Exception ex)
{
int indentation = 0;
while (ex != null)
{
if (!(ex is AggregateException))
{
Console.WriteLine("{0} {1} : {2}", string.Empty.PadLeft(indentation), ex.GetType().Name, ex.Message);
}
indentation += 2;
ex = ex.InnerException;
}
}
// if something went wrong, wait for 1 second and try again
await Task.Delay(1000);
}
}
