Support API Gateway websocket api via LambdaServer

Libraries/src/Amazon.Lambda.AspNetCoreServer.Hosting/Internal/LambdaRuntimeSupportServer.cs

@@ -175,4 +175,45 @@ public ApplicationLoadBalancerMinimalApi(IServiceProvider serviceProvider)
             }
         }
     }
+
+    /// <summary>
+    /// IServer for handlying Lambda events from an API Gateway Websocket API.
+    /// </summary>
+    public class APIGatewayWebsocketApiLambdaRuntimeSupportServer : LambdaRuntimeSupportServer
+    {
+        /// <summary>
+        /// Create instances
+        /// </summary>
+        /// <param name="serviceProvider">The IServiceProvider created for the ASP.NET Core application</param>
+        public APIGatewayWebsocketApiLambdaRuntimeSupportServer(IServiceProvider serviceProvider)
+            : base(serviceProvider)
+        {
+        }
+
+        /// <summary>
+        /// Creates HandlerWrapper for processing events from API Gateway Websocket API
+        /// </summary>
+        /// <param name="serviceProvider"></param>
+        /// <returns></returns>
+        protected override HandlerWrapper CreateHandlerWrapper(IServiceProvider serviceProvider)
+        {
+            var handler = new APIGatewayWebsocketApiMinimalApi(serviceProvider).FunctionHandlerAsync;
+            return HandlerWrapper.GetHandlerWrapper(handler, this.Serializer);
+        }
+
+        /// <summary>
+        /// Create the APIGatewayWebsocketApiV2ProxyFunction passing in the ASP.NET Core application's IServiceProvider
+        /// </summary>
+        public class APIGatewayWebsocketApiMinimalApi : APIGatewayWebsocketApiProxyFunction
+        {
+            /// <summary>
+            /// Create instances
+            /// </summary>
+            /// <param name="serviceProvider">The IServiceProvider created for the ASP.NET Core application</param>
+            public APIGatewayWebsocketApiMinimalApi(IServiceProvider serviceProvider)
+                : base(serviceProvider)
+            {
+            }
+        }
+    }
 }

Libraries/src/Amazon.Lambda.AspNetCoreServer.Hosting/ServiceCollectionExtensions.cs

@@ -27,7 +27,12 @@ public enum LambdaEventSource
         /// <summary>
         /// ELB Application Load Balancer
         /// </summary>
-        ApplicationLoadBalancer
+        ApplicationLoadBalancer,
+
+        /// <summary>
+        /// API Gateway HTTP API
+        /// </summary>
+        WebsocketApi
     }
 
     /// <summary>
@@ -106,6 +111,7 @@ private static bool TryLambdaSetup(IServiceCollection services, LambdaEventSourc
                 LambdaEventSource.HttpApi => typeof(APIGatewayHttpApiV2LambdaRuntimeSupportServer),
                 LambdaEventSource.RestApi => typeof(APIGatewayRestApiLambdaRuntimeSupportServer),
                 LambdaEventSource.ApplicationLoadBalancer => typeof(ApplicationLoadBalancerLambdaRuntimeSupportServer),
+                LambdaEventSource.WebsocketApi => typeof(APIGatewayWebsocketApiLambdaRuntimeSupportServer),
                 _ => throw new ArgumentException($"Event source type {eventSource} unknown")
             };
 

Libraries/src/Amazon.Lambda.AspNetCoreServer/APIGatewayProxyFunction.cs

@@ -5,6 +5,7 @@
 using System.Security.Claims;
 using System.Text;
 
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Primitives;
@@ -151,33 +152,9 @@ protected override void MarshallRequest(InvokeFeatures features, APIGatewayProxy
             {
                 var requestFeatures = (IHttpRequestFeature)features;
                 requestFeatures.Scheme = "https";
-                requestFeatures.Method = apiGatewayRequest.HttpMethod;
+                requestFeatures.Method = this.ParseHttpMethod(apiGatewayRequest);
 
-                string path = null;
-
-                // Replaces {proxy+} in path, if exists
-                if (apiGatewayRequest.PathParameters != null && apiGatewayRequest.PathParameters.TryGetValue("proxy", out var proxy) &&
-                    !string.IsNullOrEmpty(apiGatewayRequest.Resource))
-                {
-                    var proxyPath = proxy;
-                    path = apiGatewayRequest.Resource.Replace("{proxy+}", proxyPath);
-
-                    // Adds all the rest of non greedy parameters in apiGateway.Resource to the path
-                    foreach (var pathParameter in apiGatewayRequest.PathParameters.Where(pp => pp.Key != "proxy"))
-                    {
-                        path = path.Replace($"{{{pathParameter.Key}}}", pathParameter.Value);
-                    }
-                }
-
-                if (string.IsNullOrEmpty(path))
-                {
-                    path = apiGatewayRequest.Path;
-                }
-
-                if (!path.StartsWith("/"))
-                {
-                    path = "/" + path;
-                }
+                string path = this.ParseHttpPath(apiGatewayRequest);
 
                 var rawQueryString = Utilities.CreateQueryStringParameters(
                     apiGatewayRequest.QueryStringParameters, apiGatewayRequest.MultiValueQueryStringParameters, true);
@@ -214,13 +191,7 @@ protected override void MarshallRequest(InvokeFeatures features, APIGatewayProxy
 
                 Utilities.SetHeadersCollection(requestFeatures.Headers, apiGatewayRequest.Headers, apiGatewayRequest.MultiValueHeaders);
 
-                if (!requestFeatures.Headers.ContainsKey("Host"))
-                {
-                    var apiId = apiGatewayRequest?.RequestContext?.ApiId ?? "";
-                    var stage = apiGatewayRequest?.RequestContext?.Stage ?? "";
-
-                    requestFeatures.Headers["Host"] = $"apigateway-{apiId}-{stage}";
-                }
+                requestFeatures.Headers = this.AddMissingRequestHeaders(apiGatewayRequest, requestFeatures.Headers);
 
 
                 if (!string.IsNullOrEmpty(apiGatewayRequest.Body))
@@ -256,6 +227,7 @@ protected override void MarshallRequest(InvokeFeatures features, APIGatewayProxy
                 {
                     connectionFeatures.RemotePort = int.Parse(forwardedPort, CultureInfo.InvariantCulture);
                 }
+                connectionFeatures.ConnectionId = apiGatewayRequest.RequestContext?.ConnectionId;
 
                 // Call consumers customize method in case they want to change how API Gateway's request
                 // was marshalled into ASP.NET Core request.
@@ -335,5 +307,66 @@ protected override APIGatewayProxyResponse MarshallResponse(IHttpResponseFeature
 
             return response;
         }
+
+        /// <summary>
+        /// Get the http path from the request.
+        /// </summary>
+        /// <param name="apiGatewayRequest"></param>
+        /// <returns>string</returns>
+        protected virtual string ParseHttpPath(APIGatewayProxyRequest apiGatewayRequest)
+        {
+            string path = null;
+
+            // Replaces {proxy+} in path, if exists
+            if (apiGatewayRequest.PathParameters != null && apiGatewayRequest.PathParameters.TryGetValue("proxy", out var proxy) &&
+                !string.IsNullOrEmpty(apiGatewayRequest.Resource))
+            {
+                var proxyPath = proxy;
+                path = apiGatewayRequest.Resource.Replace("{proxy+}", proxyPath);
+
+                // Adds all the rest of non greedy parameters in apiGateway.Resource to the path
+                foreach (var pathParameter in apiGatewayRequest.PathParameters.Where(pp => pp.Key != "proxy"))
+                {
+                    path = path.Replace($"{{{pathParameter.Key}}}", pathParameter.Value);
+                }
+            }
+
+            if (string.IsNullOrEmpty(path))
+            {
+                path = apiGatewayRequest.Path;
+            }
+
+            if (!path.StartsWith("/"))
+            {
+                path = "/" + path;
+            }
+            return path;
+        }
+
+        /// <summary>
+        /// Get the http method from the request.
+        /// </summary>
+        /// <param name="apiGatewayRequest"></param>
+        /// <returns>string</returns>
+        protected virtual string ParseHttpMethod(APIGatewayProxyRequest apiGatewayRequest)
+        {
+            return apiGatewayRequest.HttpMethod;
+        }
+
+        /// <summary>
+        /// Add missing headers to request.
+        /// </summary>
+        /// <returns>IHeaderDictionary</returns>
+        protected virtual IHeaderDictionary AddMissingRequestHeaders(APIGatewayProxyRequest apiGatewayRequest, IHeaderDictionary headers)
+        {
+            if (!headers.ContainsKey("Host"))
+            {
+                var apiId = apiGatewayRequest?.RequestContext?.ApiId ?? "";
+                var stage = apiGatewayRequest?.RequestContext?.Stage ?? "";
+
+                headers["Host"] = $"apigateway-{apiId}-{stage}";
+            }
+            return headers;
+        }
     }
 }

Libraries/src/Amazon.Lambda.AspNetCoreServer/APIGatewayWebsocketApiProxyFunction.cs

@@ -0,0 +1,70 @@
+using System;
+
+using Microsoft.AspNetCore.Http;
+
+using Amazon.Lambda.APIGatewayEvents;
+using Amazon.Lambda.AspNetCoreServer.Internal;
+
+namespace Amazon.Lambda.AspNetCoreServer
+{
+    /// <summary>
+    /// Base class for ASP.NET Core Lambda functions that are getting request from API Gateway Websocket API V2 payload format.
+    ///
+    /// The http method is fixed as POST. Requests are handled using the RouteKey, so the same lambda should be referenced by multiple API Gateway routes for the ASP.NET Core IServer to successfully route requests.
+    /// </summary>
+    public abstract class APIGatewayWebsocketApiProxyFunction : APIGatewayProxyFunction
+    {
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        protected APIGatewayWebsocketApiProxyFunction()
+            : base()
+        {
+
+        }
+
+        /// <inheritdoc/>
+        /// <param name="startupMode">Configure when the ASP.NET Core framework will be initialized</param>
+        protected APIGatewayWebsocketApiProxyFunction(StartupMode startupMode)
+            : base(startupMode)
+        {
+
+        }
+
+        /// <summary>
+        /// Constructor used by Amazon.Lambda.AspNetCoreServer.Hosting to support ASP.NET Core projects using the Minimal API style.
+        /// </summary>
+        /// <param name="hostedServices"></param>
+        protected APIGatewayWebsocketApiProxyFunction(IServiceProvider hostedServices)
+            : base(hostedServices)
+        {
+            _hostServices = hostedServices;
+        }
+
+        /// <inheritdoc/>
+        /// <param name="apiGatewayRequest"></param>
+        /// <returns>string</returns>
+        protected override string ParseHttpPath(APIGatewayProxyRequest apiGatewayRequest)
+        {
+            var path = "/" + Utilities.DecodeResourcePath(apiGatewayRequest.RequestContext.RouteKey);
+            return path;
+        }
+
+        /// <inheritdoc/>
+        /// <param name="apiGatewayRequest"></param>
+        /// <returns>string</returns>
+        protected override string ParseHttpMethod(APIGatewayProxyRequest apiGatewayRequest)
+        {
+            return "POST";
+        }
+
+        /// <inheritdoc/>
+        /// <returns>IHeaderDictionary</returns>
+        protected override IHeaderDictionary AddMissingRequestHeaders(APIGatewayProxyRequest apiGatewayRequest, IHeaderDictionary headers)
+        {
+            headers = base.AddMissingRequestHeaders(apiGatewayRequest, headers);
+            headers["Content-Type"] = "application/json";
+            return headers;
+        }
+    }
+}

Libraries/src/Amazon.Lambda.AspNetCoreServer/APIGatewayWebsocketApiProxyFunction{TStartup}.cs

@@ -0,0 +1,40 @@
+using Microsoft.AspNetCore.Hosting;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Amazon.Lambda.AspNetCoreServer
+{
+    /// <summary>
+    /// APIGatewayWebsocketApiV2ProxyFunction is the base class that is implemented in a ASP.NET Core Web API. The derived class implements
+    /// the Init method similar to Main function in the ASP.NET Core and provides typed Startup. The function handler for
+    /// the Lambda function will point to this base class FunctionHandlerAsync method.
+    /// </summary>
+    /// <typeparam name ="TStartup">The type containing the startup methods for the application.</typeparam>
+    public abstract class APIGatewayWebsocketApiProxyFunction<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicMethods | DynamicallyAccessedMemberTypes.PublicConstructors)] TStartup> : APIGatewayWebsocketApiProxyFunction where TStartup : class
+    {
+        /// <summary>
+        /// Default Constructor. The ASP.NET Core Framework will be initialized as part of the construction.
+        /// </summary>
+        protected APIGatewayWebsocketApiProxyFunction()
+            : base()
+        {
+
+        }
+
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="startupMode">Configure when the ASP.NET Core framework will be initialized</param>
+        protected APIGatewayWebsocketApiProxyFunction(StartupMode startupMode)
+            : base(startupMode)
+        {
+
+        }
+
+        /// <inheritdoc/>
+        protected override void Init(IWebHostBuilder builder)
+        {
+            builder.UseStartup<TStartup>();
+        }
+    }
+}

Libraries/test/Amazon.Lambda.AspNetCoreServer.Test/Amazon.Lambda.AspNetCoreServer.Test.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.5.002.0
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Amazon.Lambda.AspNetCoreServer.Test", "Amazon.Lambda.AspNetCoreServer.Test.csproj", "{AE614E81-1148-41E0-9CA7-B1F3EB34B65E}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{AE614E81-1148-41E0-9CA7-B1F3EB34B65E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{AE614E81-1148-41E0-9CA7-B1F3EB34B65E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{AE614E81-1148-41E0-9CA7-B1F3EB34B65E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{AE614E81-1148-41E0-9CA7-B1F3EB34B65E}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {FDFB946B-997E-4736-A826-7461752C8DF4}
+	EndGlobalSection
+EndGlobal