public static IResourceBuilder AddAWSLambdaFunction()

in src/Aspire.Hosting.AWS/Lambda/LambdaExtensions.cs [32:112]
64 lines of code
4 McCabe index (conditional complexity)

    public static IResourceBuilder<LambdaProjectResource> AddAWSLambdaFunction<TLambdaProject>(this IDistributedApplicationBuilder builder, string name, string lambdaHandler, LambdaFunctionOptions? options = null) where TLambdaProject : IProjectMetadata, new()
    {
        options ??= new LambdaFunctionOptions();
        var metadata = new TLambdaProject();

        var serviceEmulator = AddOrGetLambdaServiceEmulatorResource(builder);
        IResourceBuilder<LambdaProjectResource> resource;
        // The Lambda function handler for a Class Library contains "::".
        // This is an example of a class library function handler "WebCalculatorFunctions::WebCalculatorFunctions.Functions::AddFunctionHandler".
        if (lambdaHandler.Contains("::") && AspireUtilities.IsRunningInDebugger)
        {
            // If we are running Aspire through an IDE where a debugger is attached,
            // we want to configure the Aspire resource to use a Launch Setting Profile that will be able to run the class library Lambda function.
            var project = new LambdaProjectResource(name);
            resource = builder.AddResource(project)
                .WithAnnotation(new LaunchProfileAnnotation($"{Constants.LaunchSettingsNodePrefix}{name}"))
                .WithAnnotation(new TLambdaProject());
        }
        else
        {
            var project = new LambdaProjectResource(name);
            resource = builder.AddResource(project)
                            .WithAnnotation(new TLambdaProject());
        }

        resource.WithParentRelationship(serviceEmulator);

        resource.WithOpenTelemetry();

        resource.WithEnvironment(context =>
        {
            var serviceEmulatorEndpoint = serviceEmulator.GetEndpoint("http");

            // Add the Lambda function resource on the path so the emulator can distinguish request
            // for each Lambda function.
            var apiPath = $"{serviceEmulatorEndpoint.Host}:{serviceEmulatorEndpoint.Port}/{name}";
            context.EnvironmentVariables["AWS_EXECUTION_ENV"] = $"aspire.hosting.aws#{SdkUtilities.GetAssemblyVersion()}";
            context.EnvironmentVariables["AWS_LAMBDA_RUNTIME_API"] = apiPath;
            context.EnvironmentVariables["AWS_LAMBDA_FUNCTION_NAME"] = name;
            context.EnvironmentVariables["_HANDLER"] = lambdaHandler;

            context.EnvironmentVariables["AWS_LAMBDA_LOG_FORMAT"] = options.LogFormat.Value;
            context.EnvironmentVariables["AWS_LAMBDA_LOG_LEVEL"] = options.ApplicationLogLevel.Value;

            var lambdaEmulatorEndpoint = $"http://{serviceEmulatorEndpoint.Host}:{serviceEmulatorEndpoint.Port}/?function={Uri.EscapeDataString(name)}";
            
            resource.WithAnnotation(new ResourceCommandAnnotation(
                name: "LambdaEmulator", 
                displayName: "Lambda Service Emulator", 
                updateState: context =>
                {
                    if (string.Equals(context.ResourceSnapshot.State?.Text, KnownResourceStates.Running))
                    {
                        return ResourceCommandState.Enabled;
                    }
                    return ResourceCommandState.Disabled;
                },
                executeCommand: context =>
                {
                    var startInfo = new ProcessStartInfo
                    {
                        UseShellExecute = true,
                        FileName = lambdaEmulatorEndpoint
                    };
                    Process.Start(startInfo);

                    return Task.FromResult(CommandResults.Success());
                },
                displayDescription: "Open the Lambda service emulator configured for this Lambda function",
                parameter: null,
                confirmationMessage: null,
                iconName: "Bug",
                iconVariant: IconVariant.Filled,
                isHighlighted: true)
            );
        });

        resource.WithAnnotation(new LambdaFunctionAnnotation(lambdaHandler));
        
        return resource;
    }