Endpoints without a scheme

[JobaDiniz]

When setting up Temporalio as a aspire resource, I want to get the endpoint. Turns out temporalio main endpoint on port 7233 cannot have a scheme, it's grpc, and you cannot add scheme to the endpoint.

This is not supported by Aspire.

/// <summary>
/// Provides extension methods for adding the Temporal executable resource to the application model.
/// </summary>
public static class TemporalBuilderExtensions
{
    /// <summary>
    /// Adds a Temporal executable resource to the application model.
    /// </summary>
    /// <param name="builder">The <see cref="IDistributedApplicationBuilder"/>.</param>
    /// <param name="name">The name of the resource. This name will be used as the connection string name when referenced in a dependency.</param>
    /// <param name="executablePath"></param>
    /// <param name="args"></param>
    public static IResourceBuilder<TemporalExecutableResource> AddTemporalDevelopmentServer(this IDistributedApplicationBuilder builder,
        [ResourceName] string name, string? executablePath = null, string[]? args = null)
    {
        args = args ?? [];
        string[] allArgs = args is { Length: > 0 }
            ? ["server", "start-dev", .. args]
            : ["server", "start-dev"];
        var temporal = new TemporalExecutableResource(name, executablePath);
        return builder.AddResource(temporal)
            .WithArgs(allArgs)
            .WithEndpoint(port: 7233, scheme: string.Empty, name: TemporalExecutableResource.ServerEndpointName, isProxied: false)
            .WithHttpEndpoint(port: 8233, name: "ui", isProxied: false)
            .WithHttpEndpoint(port: 52723, name: "metrics", isProxied: false);
    }
}

I added string.empty there, but when I do temporal.GetEndpoint I receive a ://localhost:7233 invalid endpoint:

var temporal = builder.AddTemporalDevelopmentServer("temporal");

var api = builder.AddProject<Projects.Torch_Api>("api")
    .WithEnvironment("Temporal:Endpoint", temporal.GetEndpoint(TemporalExecutableResource.ServerEndpointName))

Am I doing something wrong? Or does Aspire need to support such scenario?

[davidfowl]

The scheme for grpc is http. Use WithHttpEndpoint. You can get the host and port by doing this:

var temporal = builder.AddTemporalDevelopmentServer("temporal");

var endpoint = temporal.GetEndpoint(TemporalExecutableResource.ServerEndpointName);

var hostAndPort = ReferenceExpression.Create($"{endpoint.Property(EndpointProperty.Host)}:{endpoint.Property(EndpointProperty.Port)}");

var api = builder.AddProject<Projects.Torch_Api>("api")
    .WithEnvironment("Temporal:Endpoint", hostAndPort);

In 9.2 there's HostAndPort enum value.

[JobaDiniz]

Building this host and port is kinda the job of building the connection string. But using IResourceWithConnectionString requires the environment variable to be ConnectionStrings__{sourceResourceName}, and I need the environment variable to be Temporal:Endpoint.

/// <summary>
/// Represents a Temporal executable resource by using temporal command line interface.
/// </summary>
/// <param name="name"></param>
/// <param name="executablePath"></param>
public class TemporalExecutableResource(string name, string? executablePath) :
    ExecutableResource(name, executablePath ?? "temporal", string.Empty), IResourceWithConnectionString
{
    public const string ServerEndpointName = "server";

    private EndpointReference? serverReference;
    public EndpointReference ServerEndpoint =>
        serverReference ??= new(this, ServerEndpointName);

    public ReferenceExpression ConnectionStringExpression =>
        ReferenceExpression.Create(
            $"{ServerEndpoint.Property(EndpointProperty.Host)}:{ServerEndpoint.Property(EndpointProperty.Port)}"
        );
}

var temporal = builder.AddTemporalDevelopmentServer("temporal");

var api = builder.AddProject<Projects.Torch_Api>("api")
    .WithReference(temporal);

With the above code, Aspire injects an environment variable named ConnectionStrings__temporal with the actual host and port.

Is there a way to tell Aspire to use Temporal:Endpoint when injecting the connection string env var?

[afscrome]

Is there a way to tell Aspire to use Temporal:Endpoint when injecting the connection string env var?

WithReference() is highly opinionated in how it injects values - if those opinions don't work for you, you can inject your own environment variables. In your case you don't need to implement IResourceWithConnectionString and can wire up the endpoint by itself:

api
.WithEnvironment("Temporal__Endpoint", $"{temporal.GetEndpoint("http").Property(EndpointProperty.HostAndPort)}");