pubsub.go

package main

import (
	"log"
	"os"

	"cloud.google.com/go/pubsub"
	"golang.org/x/net/context"
)

func main() {
	ctx := context.Background()

	projectID := getEnv("PROJECT_ID")

	client, err := pubsub.NewClient(ctx, projectID)
	if err != nil {
		log.Fatalf("Failed to create client: %v", err)
	}

	topicName := getEnv("PUBSUB_TOPIC")

	topic, err := client.CreateTopic(ctx, topicName)
	if err != nil {
		log.Printf("Topic '%v' exists not need to recreate", topicName)
	}

	msgID, err := topic.Publish(ctx, &pubsub.Message{
		Data: []byte("Hello Henry!"),
	}).Get(ctx)
	if err != nil {
		log.Fatalf("Error publishing message: %v", err)
	}
	log.Printf("Message ID: %v", msgID)

}

func getEnv(k string) string {
	v := os.Getenv(k)
	if v == "" {
		log.Fatalf("Environment variable '%v' required and not set", k)
	}
	return v
}