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Deploying your app to Cloud Run

Google Cloud offers several options for running your code. For this example, you use Cloud Run to deploy a scalable app to Google Cloud. With zero server management, Cloud Run lets you focus on writing code. Plus, Cloud Run automatically scales to support sudden traffic spikes.

FROM mcr.microsoft.com/dotnet/core/aspnet:2.1
COPY . /app
WORKDIR /app
ENTRYPOINT ["dotnet", "Bookshelf.dll"]

Dockerfiles can be richer, but this configuration works for a lot of apps.

Cloud Run tells your app which port to listen to by setting the PORT environment variable. Bookshelf's Program.cs contains code to observe the PORT variable and listen on that port:

using Google.Cloud.Diagnostics.AspNetCore;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using System;

namespace Bookshelf
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateWebHostBuilder(args).Build().Run();
        }

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseGoogleDiagnostics(Startup.GetProjectId(), "Bookshelf", "0.01")
                .UseStartup<Startup>().UsePortEnvironmentVariable();
    }

    static class ProgramExtensions
    {
        // Google Cloud Run sets the PORT environment variable to tell this
        // process which port to listen to.
        public static IWebHostBuilder UsePortEnvironmentVariable(
            this IWebHostBuilder builder)
        {
            string port = Environment.GetEnvironmentVariable("PORT");
            if (!string.IsNullOrEmpty(port))
            {
                builder.UseUrls($"http://0.0.0.0:{port}");
            }
            return builder;
        }
    }
}

In your terminal window, deploy the app to Cloud Run using the gcloud CLI:

1. Build the app locally.

   dotnet publish -c Release
   

2. Use Cloud Build to build a Docker container and publish to Container Registry.

   gcloud builds submit --tag gcr.io/PROJECT_ID/bookshelf \
       bin/Release/netcoreapp2.1/publish
   

3. Run the container with Cloud Run.

   gcloud run deploy bookshelf --region us-central1 --platform managed \
       --image gcr.io/PROJECT_ID/bookshelf --allow-unauthenticated
   

   Your app is now viewable at the URL displayed in the output of gcloud run:

   Service [bookshelf] revision [bookshelf-00001] has been deployed and is serving traffic at
   https://bookshelf-lwuhslogjlnpofsxugoc.a.run.app
   

4. Copy the URL into your web browser to view the app.

For more information on deploying to Cloud Run, see the Cloud Run documentation.

Persist your data with Firestore

You cannot store information on your Cloud Run instances, because it is lost if the instance is restarted, and doesn't exist when new instances are created. Instead, you use a database that all your instances read from and write to.

Google Cloud offers several options for storing your data. In this example, you use Firestore to store the data for each book. Firestore is a fully managed, serverless, NoSQL document database that lets you store and query data. Firestore auto scales to meet your app needs, and scales to zero when you're not using it. Add your first book now.

1. To create a book for your deployed app, click Add book.

   
2. In the Title field, enter Moby Dick.
3. In the Author field, enter Herman Melville.

4. Click Save. There is now an entry to your Bookshelf app.

   

5. In the Google Cloud console, go to Cloud Firestore. Go to Cloud Firestore

   The data appears in Firestore. The Bookshelf app stores each book as a Firestore document with a unique ID, and all these documents are stored in a Firestore collection. For the purposes of this tutorial, the collection is called books.

   

Firestore stores the books by using the Firestore Client Library. Here is an example of fetching a Firestore document:

using Google.Cloud.Firestore;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Bookshelf.Models
{
    class FirestoreBookStore : IBookStore
    {
        private FirestoreDb _firestore;
        private CollectionReference _books;

        public FirestoreBookStore(string projectId)
        {
            _firestore = FirestoreDb.Create(projectId);
            _books = _firestore.Collection("Books");
        }

For more information on using Firestore, see Adding data to Firestore.

Store file uploads in Cloud Storage

Now that you've added a book, it's time to add the book cover image. You cannot store files on your instances. A database isn't the right choice for image files. Instead, you use Cloud Storage.

Cloud Storage is the primary blob store for Google Cloud. You can use Cloud Storage to host app assets that you want to share across Google Cloud. To use Cloud Storage, you need to create a Cloud Storage bucket, a basic container to hold your data.

1. In the Google Cloud console, go to the Cloud Storage Browser page.

   Go to the Cloud Storage Browser page

2. Click Create bucket.
3. In the Create bucket dialog, enter a name for your bucket by appending your Google Cloud project ID to the string _bucket so the name looks like YOUR_PROJECT_ID_bucket. This name is subject to the bucket name requirements. All other fields can remain at their default values.
4. Click Create.
5. After your bucket is created, objects must be made publicly accessible to be viewed by users. To make your objects publicly accessible see Making Data Public.
6. Click Edit book, and select an image to upload as your book's cover. For example, you can use this public domain image:
   
7. Click Save. You're redirected to the homepage, where there is an entry to your Bookshelf app.
   

The bookshelf app sends uploaded files to Cloud Storage by using the Cloud Storage Client Library.

using Google.Cloud.Storage.V1;
using Microsoft.AspNetCore.Http;
using System;
using System.Threading.Tasks;
using System.Web;

namespace Bookshelf.Services
{
    public class ImageUploader
    {
        private readonly string _bucketName;
        private readonly StorageClient _storageClient;

        public ImageUploader(string bucketName)
        {
            _bucketName = bucketName;
            _storageClient = StorageClient.Create();
        }

For more information on using Cloud Storage, see the Cloud Storage introduction.

Monitor your app using Google Cloud Observability

You've deployed your app and created and modified books. To monitor these events for your users, use Application Performance Management.

Monitor logs with Cloud Logging

1. In the Google Cloud, go to the Logs Explorer

   Go to Logs Explorer

   You can monitor your app in real time. If you have any issues with your app, this is one of the first places to look.

   
2. In the Resource drop-down list, select Cloud Run Revision, bookshelf.

Monitor errors with Error Reporting

1. In the Google Cloud console, go to the Error Reporting page.
   Go to Error Reporting page
   Error Reporting highlights errors and exceptions in your app and lets you set up alerting around them.
2. In your browser, go to the /Home/Throw URL in your app.
   For example, if your app is hosted at https://bookshelf-lwuhslogjlnpofsxugoc.a.run.app, then go to https://bookshelf-lwuhslogjlnpofsxugoc.a.run.app/Home/Throw.

   This generates a new test exception and sends it to Google Cloud Observability.

3. In the Google Cloud console, return to the Error Reporting page, and in a few moments the new error is visible. Click Auto Reload so you don't need to manually refresh the page.