Add Snapstart helper to AbstractAspNetCoreFunction

Author: ppittle

Libraries/src/Amazon.Lambda.AspNetCoreServer.Hosting/Amazon.Lambda.AspNetCoreServer.Hosting.csproj

@@ -27,6 +27,8 @@
     <ProjectReference Include="..\Amazon.Lambda.APIGatewayEvents\Amazon.Lambda.APIGatewayEvents.csproj" />
     <ProjectReference Include="..\Amazon.Lambda.AspNetCoreServer\Amazon.Lambda.AspNetCoreServer.csproj" />
     <ProjectReference Include="..\Amazon.Lambda.RuntimeSupport\Amazon.Lambda.RuntimeSupport.csproj" />
-  </ItemGroup>
+    <ProjectReference Include="..\Amazon.Lambda.Serialization.SystemTextJson\Amazon.Lambda.Serialization.SystemTextJson.csproj" />
+
+   </ItemGroup>
 
 </Project>

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

@@ -8,6 +8,7 @@
 using System.Text.Json.Serialization;
 using Amazon.Lambda.APIGatewayEvents;
 using Amazon.Lambda.ApplicationLoadBalancerEvents;
+using Amazon.Lambda.AspNetCoreServer.Internal;
 using Amazon.Lambda.Core;
 using Amazon.Lambda.RuntimeSupport;
 using Amazon.Lambda.RuntimeSupport.Helpers;
@@ -101,8 +102,6 @@ private class HelperLambdaContext : ILambdaContext, ICognitoIdentity, IClientCon
 
     private static class SnapstartHelperLambdaRequests
     {
-        private static readonly Uri _baseUri = new Uri("http://localhost");
-
         public static async Task ExecuteSnapstartInitRequests(string jsonRequest, int times, HandlerWrapper handlerWrapper)
         {
             var dummyRequest = new InvocationRequest(
@@ -124,108 +123,20 @@ public static async Task ExecuteSnapstartInitRequests(string jsonRequest, int ti
 
         public static async Task<string> SerializeToJson(HttpRequestMessage request, LambdaEventSource lambdaType)
         {
-            if (null == request.RequestUri)
-            {
-                throw new ArgumentException($"{nameof(HttpRequestMessage.RequestUri)} must be set.", nameof(request));
-            }
-
-            if (request.RequestUri.IsAbsoluteUri)
-            {
-                throw new ArgumentException($"{nameof(HttpRequestMessage.RequestUri)} must be relative.", nameof(request));
-            }
-
-            // make request absolut (relative to localhost) otherwise parsing the query will not work
-            request.RequestUri = new Uri(_baseUri, request.RequestUri);
-
-            var duckRequest = new
-            {
-                Body = await ReadContent(request),
-                Headers = request.Headers
-                    .ToDictionary(
-                        kvp => kvp.Key,
-                        kvp => kvp.Value.FirstOrDefault(),
-                        StringComparer.OrdinalIgnoreCase),
-                HttpMethod = request.Method.ToString(),
-                Path = "/" + _baseUri.MakeRelativeUri(request.RequestUri),
-                RawQuery = request.RequestUri?.Query,
-                Query = QueryHelpers.ParseNullableQuery(request.RequestUri?.Query)
-            };
-
-            string translatedRequestJson = lambdaType switch
+            var result = lambdaType switch
             {
                 LambdaEventSource.ApplicationLoadBalancer =>
-                    JsonSerializer.Serialize(
-                        new ApplicationLoadBalancerRequest
-                        {
-                            Body = duckRequest.Body,
-                            Headers = duckRequest.Headers,
-                            Path = duckRequest.Path,
-                            HttpMethod = duckRequest.HttpMethod,
-                            QueryStringParameters = duckRequest.Query?.ToDictionary(k => k.Key, v => v.Value.ToString())
-                        },
-                        LambdaRequestTypeClasses.Default.ApplicationLoadBalancerRequest),
+                    await HttpRequestMessageSerializer.SerializeToJson<ApplicationLoadBalancerRequest>(request),
                 LambdaEventSource.HttpApi =>
-                    JsonSerializer.Serialize(
-                        new APIGatewayHttpApiV2ProxyRequest
-                        {
-                            Body = duckRequest.Body,
-                            Headers = duckRequest.Headers,
-                            RawPath = duckRequest.Path,
-                            RequestContext = new APIGatewayHttpApiV2ProxyRequest.ProxyRequestContext
-                            {
-                                Http = new APIGatewayHttpApiV2ProxyRequest.HttpDescription
-                                {
-                                    Method = duckRequest.HttpMethod,
-                                    Path = duckRequest.Path
-                                }
-                            },
-                            QueryStringParameters = duckRequest.Query?.ToDictionary(k => k.Key, v => v.Value.ToString()),
-                            RawQueryString = duckRequest.RawQuery
-                        },
-                        LambdaRequestTypeClasses.Default.APIGatewayHttpApiV2ProxyRequest),
+                    await HttpRequestMessageSerializer.SerializeToJson<APIGatewayHttpApiV2ProxyRequest>(request),
                 LambdaEventSource.RestApi =>
-                    JsonSerializer.Serialize(
-                        new APIGatewayProxyRequest
-                        {
-                            Body = duckRequest.Body,
-                            Headers = duckRequest.Headers,
-                            Path = duckRequest.Path,
-                            HttpMethod = duckRequest.HttpMethod,
-                            RequestContext = new APIGatewayProxyRequest.ProxyRequestContext
-                            {
-                                HttpMethod = duckRequest.HttpMethod
-                            },
-                            QueryStringParameters = duckRequest.Query?.ToDictionary(k => k.Key, v => v.Value.ToString())
-                        },
-                        LambdaRequestTypeClasses.Default.APIGatewayProxyRequest),
+                    await HttpRequestMessageSerializer.SerializeToJson<APIGatewayProxyRequest>(request),
                 _ => throw new NotImplementedException(
                     $"Unknown {nameof(LambdaEventSource)}: {Enum.GetName(lambdaType)}")
             };
 
-            return translatedRequestJson;
-        }
-
-        private static async Task<string> ReadContent(HttpRequestMessage r)
-        {
-            if (r.Content == null)
-                return string.Empty;
-
-            return await r.Content.ReadAsStringAsync();
+            return result;
         }
     }
 }
-
-
-[JsonSourceGenerationOptions(WriteIndented = true)]
-[JsonSerializable(typeof(ApplicationLoadBalancerRequest))]
-[JsonSerializable(typeof(APIGatewayHttpApiV2ProxyRequest))]
-[JsonSerializable(typeof(APIGatewayProxyRequest))]
-[JsonSerializable(typeof(APIGatewayProxyRequest.ClientCertValidity))]
-[JsonSerializable(typeof(APIGatewayProxyRequest.ProxyRequestClientCert))]
-[JsonSerializable(typeof(APIGatewayProxyRequest.ProxyRequestContext))]
-[JsonSerializable(typeof(APIGatewayProxyRequest.RequestIdentity))]
-
-internal partial class LambdaRequestTypeClasses : JsonSerializerContext
-{
-}
 #endif

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

@@ -98,7 +98,7 @@ public static IServiceCollection AddAWSLambdaHosting(this IServiceCollection ser
         /// <see cref="HttpRequestMessage.RequestUri"/>.
         /// <para />.
         /// Be aware that this will invoke your applications function handler code
-        /// multiple times.  Additionally, tt uses a mock <see cref="ILambdaContext"/>
+        /// multiple times.  Additionally, it uses a mock <see cref="ILambdaContext"/>
         /// which may not be fully populated.
         /// <para />
         /// This method automatically registers with <see cref="SnapshotRestore.RegisterBeforeSnapshot"/>.

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

@@ -8,6 +8,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
+using System.Net.Http;
 using System.Reflection;
 using System.Text;
 using System.Threading.Tasks;
@@ -251,6 +253,46 @@ protected virtual IHostBuilder CreateHostBuilder()
             return builder;
         }
 
+        #if NET8_0_OR_GREATER
+        /// <summary>
+        /// Return one or more <see cref="HttpRequestMessage"/>s that will be used to invoke
+        /// Routes in your lambda function in order to initialize the asp.net and lambda pipelines
+        /// during <see cref="SnapshotRestore.RegisterBeforeSnapshot"/>,
+        /// improving the performance gains offered by SnapStart.
+        /// <para />
+        /// The returned <see cref="HttpRequestMessage"/>s must have a relative
+        /// <see cref="HttpRequestMessage.RequestUri"/>.
+        /// <para />.
+        /// Be aware that this will invoke your applications function handler code
+        /// multiple times.  Additionally, it uses a mock <see cref="ILambdaContext"/>
+        /// which may not be fully populated.
+        /// <para />
+        /// This method automatically registers with <see cref="SnapshotRestore.RegisterBeforeSnapshot"/>.
+        /// <para />
+        /// If SnapStart is not enabled, then this method is never invoked.
+        /// <para />
+        /// Example:
+        /// <para />
+        /// <code>
+        /// <![CDATA[
+        /// public class HttpV2LambdaFunction : APIGatewayHttpApiV2ProxyFunction<Startup>
+        /// {
+        ///     protected override IEnumerable<HttpRequestMessage> RegisterBeforeSnapshotRequest() =>
+        ///     [
+        ///         new HttpRequestMessage
+        ///         {
+        ///             RequestUri = new Uri("/api/ExampleSnapstartInit"),
+        ///             Method = HttpMethod.Get
+        ///         }
+        ///     ];
+        /// }
+        /// ]]>
+        /// </code>
+        /// </summary>
+        protected virtual IEnumerable<HttpRequestMessage> RegisterBeforeSnapshotRequest() =>
+            Enumerable.Empty<HttpRequestMessage>();
+        #endif
+
         private protected bool IsStarted
         {
             get
@@ -284,6 +326,37 @@ protected void Start()
                         "instead of ConfigureWebHostDefaults to make sure the property Lambda services are registered.");
             }
             _logger = ActivatorUtilities.CreateInstance<Logger<AbstractAspNetCoreFunction<TREQUEST, TRESPONSE>>>(this._hostServices);
+
+            #if NET8_0_OR_GREATER
+
+            Amazon.Lambda.Core.SnapshotRestore.RegisterBeforeSnapshot(async () =>
+            {
+                var beforeSnapstartRequests = RegisterBeforeSnapshotRequest();
+
+                foreach (var httpRequest in beforeSnapstartRequests)
+                {
+                    var invokeTimes = 5;
+
+                    var json = await HttpRequestMessageSerializer.SerializeToJson<TREQUEST>(httpRequest);
+
+                    var request = HttpRequestMessageSerializer.Deserialize<TREQUEST>(json);
+
+                    InvokeFeatures features = new InvokeFeatures();
+                    MarshallRequest(features, request, new SnapStartEmptyLambdaContext());
+
+                    var context = CreateContext(features);
+
+                    var lambdaContext = new SnapStartEmptyLambdaContext();
+
+                    for (var i = 0; i < invokeTimes; i++)
+                    {
+                        await ProcessRequest(lambdaContext, context, features);
+                    }
+                }
+            });
+
+            #endif
+
         }
 
         /// <summary>

Libraries/src/Amazon.Lambda.AspNetCoreServer/Amazon.Lambda.AspNetCoreServer.csproj

@@ -31,6 +31,7 @@
 
   <ItemGroup>
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
+    <ProjectReference Include="..\Amazon.Lambda.RuntimeSupport\Amazon.Lambda.RuntimeSupport.csproj" />
     <ProjectReference Include="..\Amazon.Lambda.Serialization.SystemTextJson\Amazon.Lambda.Serialization.SystemTextJson.csproj" />
   </ItemGroup>