Google Cloud Pub/Sub C# example

google-cloud-pubsub-example.cs

//
// Google Cloud Pub/Sub C# example
// NOTE: This is a .NET Core 1.1 console app. 
// Use "dotnet run" to run it, run setup.ps1 first.
//

using System;
using System.Collections.Generic;
using Google.Cloud.PubSub.V1;
using Google.Protobuf;
using Grpc.Core;

namespace PubSubExample
{
	public class ProgramExample
	{
		private const string ProjectId = "YOUR PROJECT ID";
		private const string TopicId = "YOUR TOPIC ID";
		private const string SubscriptionId = "YOUR SUBSCRIPTION ID";

		// To view a message in your subscription:
		// gcloud beta pubsub subscriptions pull testsub1

		public static void Main(string[] args)
		{
			PublishToTopic();
			PublishToTopic();

			// The loop is necessary as pull doesn't always brings back all your messages
			var response = ShowMessagesForSubscription();
			while (response != null && response.ReceivedMessages.Count > 0)
			{
				response = ShowMessagesForSubscription();
			}
		}

		private static void CreateTopic()
		{
			// The fully qualified name for the new topic
			var topicName = new TopicName(ProjectId, TopicId);

			// Creates the new topic
			PublisherClient publisher = PublisherClient.Create();
			Topic topic = publisher.CreateTopic(topicName);
			Console.WriteLine($"Topic {topic.Name} created.");
		}

		private static void ListTopics()
		{
			// List all topics for the project
			PublisherClient publisher = PublisherClient.Create();
			var topics = publisher.ListTopics(new ProjectName(ProjectId));
			foreach (Topic topic1 in topics)
			{
				Console.WriteLine(topic1.Name);
			}
		}

		private static void PublishToTopic()
		{
			var topicName = new TopicName(ProjectId, TopicId);

			PublisherClient publisher = PublisherClient.Create();

			// Create a message
			var message = new PubsubMessage()
			{
				Data = ByteString.CopyFromUtf8("hello world")
			};
			message.Attributes.Add("myattrib", "its value");

			// Add it to the list of messages to publish
			var messageList = new List<PubsubMessage>() { message };

			// Publish it
			Console.WriteLine("Publishing...");
			var response = publisher.Publish(topicName, messageList);

			// Get the message ids GCloud gave us
			Console.WriteLine("  Message ids published:");
			foreach (string messageId in response.MessageIds)
			{
				Console.WriteLine($"  {messageId}");
			}
		}

		private static PullResponse ShowMessagesForSubscription()
		{
			var subscriptionName = new SubscriptionName(ProjectId, SubscriptionId);

			var subscription = SubscriberClient.Create();

			try
			{
				PullResponse response = subscription.Pull(subscriptionName, true, 10);

				var all = response.ReceivedMessages;

				foreach (ReceivedMessage message in all)
				{
					string id = message.Message.MessageId;
					string publishDate = message.Message.PublishTime.ToDateTime().ToString("dd-M-yyyy HH:MM:ss");
					string data = message.Message.Data.ToStringUtf8();

					Console.WriteLine($"{id} {publishDate} - {data}");

					Console.Write("  Acknowledging...");
					subscription.Acknowledge(subscriptionName, new string[] { message.AckId });
					Console.WriteLine("done");
				}

				return response;
			}
			catch (RpcException e)
			{
				Console.WriteLine("Something went wrong: {0}", e.Message);
				return null;
			}
		}
	}
}

project.json

{
	"version": "1.0.0-*",
	"buildOptions": {
		"debugType": "portable",
		"emitEntryPoint": true
	},

	"dependencies": {
		"Google.Cloud.PubSub.V1": "1.0.0-beta06",
		"Microsoft.Extensions.Logging": "1.0.0",
		"Microsoft.Extensions.Logging.Console": "1.0.0",
		"Microsoft.Extensions.Logging.Debug": "1.0.0"
	},

	"frameworks": {
		"netcoreapp1.1": {
			"dependencies": {
				"Microsoft.NETCore.App": {
					"type": "platform",
					"version": "1.1.0"
				}
			},
			"imports": "dnxcore50"
		}
	}
}

setup.ps1

#
# Once you have a Google cloud account setup:
#
# 1. Download and install the Google Cloud Windows SDK
# 2. Inside the browser, download a credentials.json file
# 3. Put the .json file inside the directory you run this example.
# 4. Run "gcloud components install beta"
# 5. Update the project and zone inside this script.
# 6. Run this script before performing a "dotnet run"
#

$env:HOME="$(pwd)"
$env:GOOGLE_APPLICATION_CREDENTIALS="$(pwd)\google-cloud-credentials.json"
$project="YOUR-PROJECT-ID"
$zone="europe-west1-b"

gcloud config set compute/zone $zone
gcloud config set project $project