| // Copyright 2016 Google Inc. All Rights Reserved. |
| // |
| // 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 main contains a client which pulls messages from a subscription and prints them. |
| package main |
| |
| import ( |
| "flag" |
| "fmt" |
| "log" |
| "os" |
| "os/signal" |
| "time" |
| |
| "golang.org/x/net/context" |
| |
| "google.golang.org/cloud/pubsub" |
| ) |
| |
| var ( |
| projID = flag.String("p", "", "The ID of your Google Cloud project.") |
| subName = flag.String("s", "", "The name of the subscription to pull from") |
| numConsume = flag.Int("n", 10, "The number of messages to consume") |
| ) |
| |
| func main() { |
| flag.Parse() |
| |
| if *projID == "" { |
| log.Fatal("-p is required") |
| } |
| if *subName == "" { |
| log.Fatal("-s is required") |
| } |
| |
| quit := make(chan os.Signal, 1) |
| signal.Notify(quit, os.Interrupt) |
| |
| ctx := context.Background() |
| |
| client, err := pubsub.NewClient(ctx, *projID) |
| if err != nil { |
| log.Fatalf("creating pubsub client: %v", err) |
| } |
| |
| sub := client.Subscription(*subName) |
| |
| it, err := sub.Pull(ctx, pubsub.MaxExtension(time.Minute)) |
| if err != nil { |
| fmt.Printf("error constructing iterator: %v", err) |
| return |
| } |
| defer it.Stop() |
| |
| go func() { |
| <-quit |
| it.Stop() |
| }() |
| |
| for i := 0; i < *numConsume; i++ { |
| m, err := it.Next() |
| if err == pubsub.Done { |
| break |
| } |
| if err != nil { |
| fmt.Printf("advancing iterator: %v", err) |
| break |
| } |
| fmt.Printf("got message: %v\n", string(m.Data)) |
| m.Done(true) |
| } |
| } |