tests/integration: Move of naming/snapshot clientv3 tests (and yaml reference)

path change in clientv3/yaml/config_test

git mv clientv3/naming/grpc_test.go         tests/integration/clientv3/grpc_test.go
git mv clientv3/snapshot/*_test.go          tests/integration/snapshot
git mv clientv3/{main_test.go,example_*.go} tests/integration/clientv3/examples/

tests/integration/clientv3/examples/example_lease_test.go

@@ -0,0 +1,141 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package clientv3_test
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"go.etcd.io/etcd/v3/clientv3"
+)
+
+func ExampleLease_grant() {
+	cli, err := clientv3.New(clientv3.Config{
+		Endpoints:   endpoints,
+		DialTimeout: dialTimeout,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer cli.Close()
+
+	// minimum lease TTL is 5-second
+	resp, err := cli.Grant(context.TODO(), 5)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// after 5 seconds, the key 'foo' will be removed
+	_, err = cli.Put(context.TODO(), "foo", "bar", clientv3.WithLease(resp.ID))
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func ExampleLease_revoke() {
+	cli, err := clientv3.New(clientv3.Config{
+		Endpoints:   endpoints,
+		DialTimeout: dialTimeout,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer cli.Close()
+
+	resp, err := cli.Grant(context.TODO(), 5)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = cli.Put(context.TODO(), "foo", "bar", clientv3.WithLease(resp.ID))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// revoking lease expires the key attached to its lease ID
+	_, err = cli.Revoke(context.TODO(), resp.ID)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	gresp, err := cli.Get(context.TODO(), "foo")
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println("number of keys:", len(gresp.Kvs))
+	// Output: number of keys: 0
+}
+
+func ExampleLease_keepAlive() {
+	cli, err := clientv3.New(clientv3.Config{
+		Endpoints:   endpoints,
+		DialTimeout: dialTimeout,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer cli.Close()
+
+	resp, err := cli.Grant(context.TODO(), 5)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = cli.Put(context.TODO(), "foo", "bar", clientv3.WithLease(resp.ID))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// the key 'foo' will be kept forever
+	ch, kaerr := cli.KeepAlive(context.TODO(), resp.ID)
+	if kaerr != nil {
+		log.Fatal(kaerr)
+	}
+
+	ka := <-ch
+	fmt.Println("ttl:", ka.TTL)
+	// Output: ttl: 5
+}
+
+func ExampleLease_keepAliveOnce() {
+	cli, err := clientv3.New(clientv3.Config{
+		Endpoints:   endpoints,
+		DialTimeout: dialTimeout,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer cli.Close()
+
+	resp, err := cli.Grant(context.TODO(), 5)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = cli.Put(context.TODO(), "foo", "bar", clientv3.WithLease(resp.ID))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// to renew the lease only once
+	ka, kaerr := cli.KeepAliveOnce(context.TODO(), resp.ID)
+	if kaerr != nil {
+		log.Fatal(kaerr)
+	}
+
+	fmt.Println("ttl:", ka.TTL)
+	// Output: ttl: 5
+}