AppHost Setup

Start by creating a folder Aspire to keep things separated. Inside the folder create two new projects and make sure they use the latest versions:

1. Aspire.ServiceDefaults
2. Aspire.AppHost

After the two projects are created make sure they use the latest NuGet versions. The Aspire.AppHost project is not using NuGet, in the .csproj file edit the SDK version to the latest, 13.3.4.

Let’s start by running the Aspire.AppHost and see what we get out of the box.

If you get an error about using an unsecured transport, add the following line in the launchSettings.json file under environmentVariables:

"ASPIRE_ALLOW_UNSECURED_TRANSPORT": "true"

Adding the SQL Server

Aspire makes it really easy to set up your projects but also external dependencies, let’s start by adding a SQL server to the resources. Add the following NuGet package to the project:

Aspire.Hosting.SqlServer

Next, replace the code in AppHost.cs with the following:

var builder = DistributedApplication.CreateBuilder(args);

var sqlPassword = builder.AddParameter("SqlPassword");

var sql = builder
    .AddSqlServer("sql", port: 2026, password: sqlPassword)
    .WithDataVolume("AspireDataVolume");

var db = sql.AddDatabase("OnlineToestemmingDb", databaseName: "OnlineToestemming");


builder.Build().Run();

Let’s run the application and discover what Aspire did.

First it lets the developer create a password. When you start the solution, Aspire will ask for it first so we do not have to specify it. Provide a strong password in the Aspire UI and make sure it is saved to the user secrets.

Secondly, it sets up the AddSqlServer on port 2026, uses a DataVolume named AspireDataVolume. Without a data volume all data is removed when you turn off your application.

Creating the SQL server might take some time depending on your machine and internet speed.

Lastly, it creates a new database inside the SQL server.

In Docker, a couple of things have happened as well, run the following commands:

docker volume ls

This will show the volumes created inside docker, you will see your new volume here

docker ps

This command shows you all the containers running. If everything is correct you will have one container running: mcr.microsoft.com/mssql/server:2022-latest. One thing to mention is the port forward: 127.0.0.1:32769->1433/tcp. The port that is shown is not the same as the port setup in Aspire. This happens because Aspire provides a proxy between you and the docker instance.

You can sign-in to the SQL server with SQL server management studio. Use the server name 127.0.0.1,2026, sa as username and provide the password you created to sign into your SQL database server.

In the object explorer you will see the newly created database: OnlineToestemming.

Let’s shut down Aspire and implement some improvements into our setup.

After Aspire is stopped and you were to check docker again you will observe that SQL Server has stopped, also in SQL Management Studio the server has become unavailable.

This might become an issue, for example if your tests or other applications depend on the SQL Server. This can be solved by setting a lifetime to SQL Server.

.WithLifetime(ContainerLifetime.Persistent)

And while we are making improvements, let’s disable the proxy support so that in docker we have the same outbound port:

.WithEndpointProxySupport(proxyEnabled: false)

After you made the changes restart the Aspire AppHost application, wait for the server to become available and execute the docker ps command again in the terminal.

You can see that the port will now be 2026, 127.0.0.1:2026->1433/tcp and when you stop the application it will keep running (until you shut down your machine)

The next step is connecting the rest of the solution to the Aspire app host.