Setting Up a Backend for a Game Using Azure Services

In this chapter, we will set up a backend for a game app with real-time communication. We will not only create a backend that can scale up to handle a large number of users but also scale down when the number of users is reduced. To build that backend, we will use a serverless architecture based on services in Microsoft Azure.

The following topics will be covered in this chapter:

• Understanding the different Azure serverless services
• Creating a SignalR service in Microsoft Azure
• Using Azure Functions as an application programming interface (API)

Technical requirements

To be able to complete this project, you need to have Visual Studio for Mac or PC installed, as well as the necessary .NET MAUI components. See Chapter 1, Introduction to .NET MAUI, for more details on how to set up your environment.

You also need an Azure account. If you have a Visual Studio subscription, there are a specific amount of Azure credits included each month. To activate your Azure benefits, go to https://my.visualstudio.com.

You can also create a free account, where you can use selected services for free over 12 months. You will get $200 worth of credit to explore any Azure service for 30 days, and you can also use the free services at any time. Read more at https://azure.microsoft.com/en-us/free/.

If you do not have and do not want to sign up for a free Azure account, you can use local development tools to run the services without Azure.

You can find the full source for the code in this chapter at https://github.com/PacktPublishing/MAUI...

Project overview

The main aim of this project will be to set up the backend for a game. A large part of the project will be the configuration that we will carry out in the Azure portal. We will also write some code for the Azure functions that will handle the SignalR connections and a bit of the game logic and state. SignalR is a library that makes real-time communication in applications easier. Azure SignalR is a service that makes it easier to connect multiple clients to send messages via the SignalR library. SignalR is described in more detail later. There will be functions to return information about the SignalR connection, manage matching players to play against each other, and post the result of each player’s turn to the SignalR service.

The following diagram shows an overview of the architecture of this application:

Figure 9.1 – Application architecture

The estimated time to complete this part of the project is about 2 hours.

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Understanding the different Azure serverless services

Before we start to build a backend with a serverless architecture, we need to define what serverless means. In a serverless architecture, the code will run on a server, but we don’t need to worry about that; the only thing we need to focus on is building our software. We let someone else handle everything to do with servers. We don’t need to think about how much memory or central processing units (CPUs) the server needs, or even how many servers we need. When we use services in Azure, Microsoft takes care of this for us.

Azure SignalR Service

Azure SignalR Service is a service in Microsoft Azure for real-time communication between a server and clients. The service will push content to the clients without them having to poll the server to get content updates. SignalR can be used for multiple types of applications, including mobile applications, web applications, and desktop applications.

SignalR will use WebSockets...

Building the serverless backend

In this section, we will set up the backend based on the services described in the preceding section.

Creating a SignalR service

The first service that we will set up is the one for SignalR. To create such a service, proceed as follows:

1. Go to the Azure portal at https://portal.azure.com.
2. Create a new resource. The SignalR Service resource is in the Web & Mobile category.
3. Provide a name for the resource in the form.
4. Select the subscription you want to use for this project.

   We recommend that you create a new Resource group and use it for all the resources that we will create for this project. The reason that we want one resource group is that it is easier to track which resources are related to this project, and it is also easier to delete all the resources together.

5. Select a location that is close to your users.
6. Select a pricing tier. For this project, we will use the Free tier. We can always use the Free tier for...

Deploying the functions to Azure

The final step in this chapter is to deploy the functions to Azure. You can do that as a part of a continuous integration/continuous deployment (CI/CD) pipeline – for example, with Azure DevOps. But the easiest way to deploy the functions, in this case, is to do it directly from Visual Studio. Perform the following steps to deploy the functions:

1. Right-click on the SticksAndStones.Functions project and select Publish.
2. Select Azure as the destination for publishing and click Next:

Figure 9.14 – Target selection when publishing

3. Choose Azure Function App (Windows) in the Specific target tab, then click Next:

Figure 9.15 – Container selection when publishing

4. Sign in to the same Microsoft account that we used in the Azure portal when we were creating the Function App resource.
5. Select the subscription that contains the function app. All function...

Summary

In this chapter, we started by learning about a few Azure services, including SignalR, and Functions. Then, we created the services in Azure that our game server backend would need – a SignalR service for real-time communication, and finally, the Functions service to host our backend functions. After this, we implemented the Azure functions that would provide the functionality for our game.

We wrapped up this chapter by publishing our function code to the Azure Functions instance in Azure.

In the next chapter, we will build a game app that will use the backend we have built in this project.