// CreateGooglePubSubClient returns client communicate with google Pub/Sub service
func CreateGooglePubSubClient() (*pubsub.Client, error) {
envValue := os.Getenv(NDGooglePubSubURL)
if envValue != "" {
googlePubSubURL = envValue
}
envValue = os.Getenv(NDGoogleProjectID)
if envValue != "" {
googleProjectID = envValue
}
ctx := cloud.NewContext(googleProjectID, http.DefaultClient)
o := []cloud.ClientOption{
cloud.WithBaseHTTP(http.DefaultClient),
cloud.WithEndpoint(googleDatastoreURL),
}
client, _ := pubsub.NewClient(ctx, googleProjectID, o...)
return client, nil
}
// This example demonstrates calling the Cloud Pub/Sub API.
//
// Before running this example, be sure to enable Cloud Pub/Sub
// service on your project in Developer Console at:
// https://console.developers.google.com/
//
// Unless you run this sample on Compute Engine instance, please
// create a new service account and download a JSON key file for it at
// the developer console: https://console.developers.google.com/
//
// It has the following subcommands:
//
// create_topic <name>
// delete_topic <name>
// create_subscription <name> <linked_topic>
// delete_subscription <name>
// publish <topic> <message>
// pull_messages <subscription> <numworkers>
// publish_messages <topic> <numworkers>
//
// You can choose any names for topic and subscription as long as they
// follow the naming rule described at:
// https://cloud.google.com/pubsub/overview#names
//
// You can create/delete topics/subscriptions by self-explanatory
// subcommands.
//
// The "publish" subcommand is for publishing a single message to a
// specified Cloud Pub/Sub topic.
//
// The "pull_messages" subcommand is for continuously pulling messages
// from a specified Cloud Pub/Sub subscription with specified number
// of workers.
//
// The "publish_messages" subcommand is for continuously publishing
// messages to a specified Cloud Pub/Sub topic with specified number
// of workers.
func main() {
flag.Parse()
argv := flag.Args()
checkArgs(argv, 1)
if *projID == "" {
usageAndExit("Please specify Project ID.")
}
oldStyle := map[string]func(ctx context.Context, argv []string){
"publish": publish,
"pull_messages": pullMessages,
"publish_messages": publishMessages,
}
newStyle := map[string]func(client *pubsub.Client, argv []string){
"create_topic": createTopic,
"delete_topic": deleteTopic,
"list_topics": listTopics,
"list_topic_subscriptions": listTopicSubscriptions,
"topic_exists": checkTopicExists,
"create_subscription": createSubscription,
"delete_subscription": deleteSubscription,
"subscription_exists": checkSubscriptionExists,
"list_subscriptions": listSubscriptions,
}
subcommand := argv[0]
if f, ok := oldStyle[subcommand]; ok {
httpClient, err := newClient(*jsonFile)
if err != nil {
log.Fatalf("clientAndId failed, %v", err)
}
ctx := cloud.NewContext(*projID, httpClient)
f(ctx, argv)
} else if f, ok := newStyle[subcommand]; ok {
client, err := pubsub.NewClient(context.Background(), *projID)
if err != nil {
log.Fatalf("creating pubsub client: %v", err)
}
f(client, argv)
} else {
usageAndExit(fmt.Sprintf("Function not found for %s", subcommand))
}
}