GCP Pubsub Listener

listener.go

package main

// example
// go run ./main.go <gcp-project-name> <pubsub-subscription-name> | jq -r .payload.source.table

import (
	"context"
	"fmt"
	"os"
	"os/signal"

	"cloud.google.com/go/pubsub"
)

func main() {
	if len(os.Args) < 3 {
		fmt.Fprintf(os.Stderr, "usage: %s projectID subscriptionID\n", os.Args[0])
		os.Exit(1)
	}

	projectID := os.Args[1]
	subscriptionID := os.Args[2]
	fmt.Fprintf(os.Stderr, "projectID: %s, subscriptionID: %s\n", projectID, subscriptionID)

	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
	client, err := pubsub.NewClient(ctx, projectID)
	if err != nil {
		fmt.Fprintf(os.Stderr, "pubsub.NewClient: %s", err)
		os.Exit(1)
	}

	sub := client.Subscription(subscriptionID)
	defer cancel()

	sub.Receive(ctx, func(ctx context.Context, msg *pubsub.Message) {
		fmt.Println(string(msg.Data))
		msg.Ack()
	})

}