pubsub.go

package hello

import (
	"encoding/base64"
	"fmt"
	"net/http"

	"google.golang.org/appengine"

	"golang.org/x/oauth2/google"
	"google.golang.org/api/pubsub/v1"
)

func init() {
	http.HandleFunc("/publish", publishHandler)
}

func publishHandler(w http.ResponseWriter, r *http.Request) {
	ctx := appengine.NewContext(r)
	hc, err := google.DefaultClient(ctx,  pubsub.PubsubScope)
	if err != nil {
		handleError(w, err)
		return
	}

	pubsubService, err := pubsub.New(hc)
	if err != nil {
		handleError(w, err)
		return
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}

	msgData := []byte("test!")

	resp, err := pubsubService.Projects.Topics.Publish(
		"projects/YOUR-PROJECT-ID/topics/YOUR-TOPIC-ID",
		&pubsub.PublishRequest{
			Messages: []*pubsub.PubsubMessage{
				{
					Data: base64.StdEncoding.EncodeToString(msgData),
				},
			},
		},
	).Do()
	if err != nil {
		handleError(w, err)
		return
	}
	fmt.Fprintf(w, "ok! id: %q", resp.MessageIds[0])
}

func handleError(w http.ResponseWriter, err error) {
	// TODO(you): log the error, etc.
	http.Error(w, err.Error(), http.StatusInternalServerError)
}