Example of using dotnet watch with Aspire

[En3Tho]

This might come in handy for others who are curious how to run projects with dotnet watch enabled. Basically it's a full copy of what AddProject does but with ExecutableResource instead of ProjectResource. I'm not sure this requires a pull request but maybe it is worth being an example in the docs or something like that.

public static  IResourceBuilder<ExecutableResource> AddProjectWithDotnetWatch<TProject>(this IDistributedApplicationBuilder builder, string name) where TProject : IServiceMetadata, new()
    {
        var serviceMetadata = new TProject();
        var project = new ExecutableResource(name, "dotnet", Path.GetDirectoryName(serviceMetadata.ProjectPath)!, ["watch", "--non-interactive"]);
        var executableBuilder = builder.AddResource(project);
        // We only want to turn these on for .NET projects, ConfigureOtlpEnvironment works for any resource type that
        // implements IDistributedApplicationResourceWithEnvironment.
        executableBuilder.WithEnvironment("OTEL_DOTNET_EXPERIMENTAL_OTLP_EMIT_EXCEPTION_LOG_ATTRIBUTES", "true");
        executableBuilder.WithEnvironment("OTEL_DOTNET_EXPERIMENTAL_OTLP_EMIT_EVENT_LOG_ATTRIBUTES", "true");
        executableBuilder.WithOtlpExporter();
        executableBuilder.WithEnvironment((context) =>
        {
            if (context.PublisherName == "manifest")
            {
                return;
            }

            // Enable ANSI Control Sequences for colors in Output Redirection
            context.EnvironmentVariables["DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION"] = "true";

            // Enable Simple Console Logger Formatting with a UTC timestamp similar to RFC3339Nano that Docker generates
            context.EnvironmentVariables["LOGGING__CONSOLE__FORMATTERNAME"] = "simple";
            context.EnvironmentVariables["LOGGING__CONSOLE__FORMATTEROPTIONS__TIMESTAMPFORMAT"] =
                $"{TimestampParser.DisplayFormat} ";
        });
        executableBuilder.WithAnnotation(serviceMetadata);
        return executableBuilder;
    }

[DamianEdwards]

We intend to update dotnet watch to properly support working with Aspire AppHost projects. I've logged dotnet/sdk#36971 to track this feature.

[danmoseley]

Thanks @En3Tho . I'm going to close this as I don't think there's further action but folks can find your example.

[En3Tho]

@danmoseley Should there be a tracking issue for dotnet watch support in Aspire? Maybe I've missed it? Or that sdk issue is enough?

[danmoseley]

I think the SDK issue will likely cover it but you'd be welcome to open a linked issue here for the scenario if there isn't one.