func rawService(ctx context.Context) *raw.Service {
return internal.Service(ctx, "pubsub", func(hc *http.Client) interface{} {
svc, _ := raw.New(hc)
svc.BasePath = baseAddr()
return svc
}).(*raw.Service)
}
func newPubSubService(client *http.Client, endpoint string) (*apiService, error) {
s, err := raw.New(client)
if err != nil {
return nil, err
}
s.BasePath = endpoint
return &apiService{s: s}, nil
}
func rawService(ctx context.Context) *raw.Service {
baseAddr := func() string {
// Environment variables for gcloud emulator:
// https://cloud.google.com/sdk/gcloud/reference/beta/emulators/pubsub/
if host := os.Getenv("PUBSUB_EMULATOR_HOST"); host != "" {
return "http://" + host + "/"
}
return prodAddr
}
return internal.Service(ctx, "pubsub", func(hc *http.Client) interface{} {
svc, _ := raw.New(hc)
svc.BasePath = baseAddr()
return svc
}).(*raw.Service)
}
// NewClient create a new PubSub client.
func NewClient(ctx context.Context, projectID string, opts ...cloud.ClientOption) (*Client, error) {
o := []cloud.ClientOption{
cloud.WithEndpoint(prodAddr),
cloud.WithScopes(raw.PubsubScope, raw.CloudPlatformScope),
cloud.WithUserAgent(userAgent),
}
o = append(o, opts...)
httpClient, endpoint, err := transport.NewHTTPClient(ctx, o...)
if err != nil {
return nil, fmt.Errorf("dialing: %v", err)
}
s, err := raw.New(httpClient)
if err != nil {
return nil, err
}
s.BasePath = endpoint
c := &Client{
projectID: projectID,
s: s,
}
return c, nil
}
func main() {
// Make sure we flush the log before quitting:
defer log.Flush()
// Connect to GCE (either from GCE permissions, JSON file, or ENV-vars):
client, err := google.DefaultClient(context.Background(), pubsub.PubsubScope)
if err != nil {
log.Criticalf("Unable to authenticate to GCE! (%s)", err)
os.Exit(2)
}
// Get a DNS service-object:
pubsubService, err := pubsub.New(client)
if err != nil {
log.Criticalf("Failed to connect to PUB/SUB! %v", err)
os.Exit(2)
}
// Build the topic and subscription names:
fullTopicName := fmt.Sprintf("projects/%v/topics/%v", *project, *topic)
fullSubscriptionName := fmt.Sprintf("projects/%v/subscriptions/%v", *project, "tail-pubsub")
// Create a subscription:
log.Debugf("Making subscription to topic (%v) ...", fullTopicName)
sub := &pubsub.Subscription{Topic: fullTopicName}
subscription, err := pubsubService.Projects.Subscriptions.Create(fullSubscriptionName, sub).Do()
if err != nil {
log.Warnf("Failed to create subscription to topic (%v): %v", fullTopicName, err)
log.Debugf("Getting existing subscription (%v) to topic (%v) ...", fullSubscriptionName, fullTopicName)
subscription, err = pubsubService.Projects.Subscriptions.Get(fullSubscriptionName).Do()
if err != nil {
log.Criticalf("Couldn't even get existing subscription (%v): %v", fullSubscriptionName, err)
os.Exit(2)
}
}
log.Debugf("Subscription (%s) was created", subscription.Name)
// Prepare a pull-request:
pullRequest := &pubsub.PullRequest{
ReturnImmediately: true,
MaxMessages: *batchsize,
}
// Now attack the pub/sub API:
for {
log.Debugf("Polling for messages ...")
pullResponse, err := pubsubService.Projects.Subscriptions.Pull(fullSubscriptionName, pullRequest).Do()
if err != nil {
log.Errorf("Failed to pull messages from subscription (%v): %v", fullSubscriptionName, err)
} else {
for _, receivedMessage := range pullResponse.ReceivedMessages {
messageData, err := base64.StdEncoding.DecodeString(receivedMessage.Message.Data)
if err != nil {
log.Warnf("Failed to decode message: %v", err)
} else {
log.Infof("Message: %v", string(messageData))
ackRequest := &pubsub.AcknowledgeRequest{
AckIds: []string{receivedMessage.AckId},
}
if _, err = pubsubService.Projects.Subscriptions.Acknowledge(fullSubscriptionName, ackRequest).Do(); err != nil {
log.Warnf("Failed to acknowledge messages: %v", err)
}
}
}
}
// Sleep until trying again:
time.Sleep(1 * time.Second)
}
}