base on Framework for an API Gateway endorsed by the .NET Foundation as revolutionary! # AspNetCore.ApiGateway ## Asp Net Core Api Gateway package. |Packages|Version|Downloads| |---------------------------|:---:|:---:| |*AspNetCore.ApiGateway*|[](https://www.nuget.org/packages/AspNetCore.ApiGateway)|[](https://www.nuget.org/packages/AspNetCore.ApiGateway)| |*Veritas.AspNetCore.ApiGateway.Minimal*|[](https://www.nuget.org/packages/Veritas.AspNetCore.ApiGateway.Minimal)|[](https://www.nuget.org/packages/Veritas.AspNetCore.ApiGateway.Minimal)| |*AspNetCore.ApiGateway.Client*|[](https://www.nuget.org/packages/AspNetCore.ApiGateway.Client)|[](https://www.nuget.org/packages/AspNetCore.ApiGateway.Client)| |*ts-aspnetcore-apigateway-client*|[](https://www.npmjs.com/package/ts-aspnetcore-apigateway-client)|[](https://www.npmjs.com/package/ts-aspnetcore-apigateway-client)| ```diff + This project has been on-boarded by the .NET Foundation, in the Seed category. ``` Read [more](https://github.com/dotnet-foundation/projects/issues/255). Social Media: LinkedIn [post](https://www.linkedin.com/feed/update/urn:li:activity:7168255226624372736/). [](https://www.linkedin.com/feed/update/urn:li:activity:7168255226624372736/) ||**More of my open-source projects**|| |---------------------------|---|:---:| |*Website AI Assistant*| AI Assistant built using ML .NET, Microsoft's machine learning platform, to help visitors to your website, narrow down which of the offered products or services suits their needs.|[Browse](https://github.com/VeritasSoftware/WebsiteAIAssistant)| |*Live Health Checks*|Real-Time Api Health Check Monitoring system|[Browse](https://github.com/VeritasSoftware/LiveHealthChecks)| |*.NET WebRTC*|A .NET library for WebRTC, enabling real-time communication in your web applications. Audio+video chat, screen sharing, text chat, file transfer etc.<br>`Angular`, `React` & `Blazor` clients.|[Browse](https://github.com/VeritasSoftware/WebRTC)| ## Background The microservices architecture uses an Api Gateway as shown below.  **The package:** * Makes creating an Api Gateway a breeze!! The framework is available as a * **RESTful Microservice Facade.** * **RESTful Minimal API Facade.** * **Azure Functions Facade.** ## Gateway as a RESTful Minimal API Facade A Minimal API in ASP.NET Core is designed to create lightweight HTTP APIs with minimal dependencies, making it ideal for microservices or small applications. It uses concise syntax, top-level statements, and avoids the overhead of controllers. The API Gateway has be implemented as a Minimal API, which acts as a facade over your backend microservices. Read [**more**](/Docs/README_MinimalAPI.md) ## Gateway as an Azure Functions Facade The API Gateway has be implemented as Azure Functions, which acts as a facade over your backend microservices. Real easy to integrate the library into a Functions project. Seamlessly transition you Azure Functions knowledge to the Api Gateway. Read [**more**](/Docs/README_AzureFunctions.md) ## Gateway as a RESTful Microservice Facade ## Features * Swagger * Authorization * Filters * Action * Exception * Result * Load balancing * Response caching * Web sockets * Request aggregation * Middleware service * Logging * Clients available in * .NET * Typescript ## Gateway as a RESTful Microservice Facade ### Your **Gateway API** is a microservice which exposes endpoints that are a **facade** over your backend API endpoints. * HEAD * GET * POST * PUT * PATCH * DELETE <div> </div> <img src="/Docs/FacadeDesignPattern.PNG" style="width:60%;height:auto;max-width:500px;" alt="API Gateway Facade" > ## Implementation In the solution, there are 2 **back end APIs** : **Weather API** and **Stock API**. For eg. To make a GET call to the backend API, you would set up an Api and a GET Route in your Gateway API's **Api Orchestrator**. Then, the client app would make a GET call to the Gateway API which would make a GET call to the backend API using HttpClient. ## In your Backend API Let us say you have a GET endpoint like this. * **HTTP GET - /weatherforecast/forecast** ## In your Gateway API You add a Route for the backend GET call in the **Api Orchrestrator**. You create a backend API with ApiKey called **weatherservice** for eg. And, a Route with RouteKey called **forecast** for eg. So, the call to the Gateway would become: * **HTTP GET - /weatherservice/forecast** **Add a reference to the package and...** * Create an **Api Orchestration**. You create an Api (weatherservice) and add a Route (forecast). ```C# public static class ApiOrchestration { public static void Create(IApiOrchestrator orchestrator, IApplicationBuilder app) { var serviceProvider = app.ApplicationServices; var weatherService = serviceProvider.GetService<IWeatherService>(); var weatherApiClientConfig = weatherService.GetClientConfig(); orchestrator.StartGatewayHub = true; orchestrator.GatewayHubUrl = "https://localhost:44360/GatewayHub"; orchestrator.AddApi("weatherservice", "http://localhost:63969/") //Get .AddRoute("forecast", GatewayVerb.GET, new RouteInfo { Path = "weatherforecast/forecast", ResponseType = typeof(IEnumerable<WeatherForecast>) }) //Head .AddRoute("forecasthead", GatewayVerb.HEAD, new RouteInfo { Path = "weatherforecast/forecast" }) //Get with params .AddRoute("typewithparams", GatewayVerb.GET, new RouteInfo { Path = "weatherforecast/types/{index}"}) //Get using custom HttpClient .AddRoute("types", GatewayVerb.GET, new RouteInfo { Path = "weatherforecast/types", ResponseType = typeof(string[]), HttpClientConfig = weatherApiClientConfig }) //Get with param using custom HttpClient .AddRoute("type", GatewayVerb.GET, new RouteInfo { Path = "weatherforecast/types/", ResponseType = typeof(WeatherTypeResponse), HttpClientConfig = weatherApiClientConfig }) //Get using custom implementation .AddRoute("forecast-custom", GatewayVerb.GET, weatherService.GetForecast) //Post .AddRoute("add", GatewayVerb.POST, new RouteInfo { Path = "weatherforecast/types/add", RequestType = typeof(AddWeatherTypeRequest), ResponseType = typeof(string[])}) //Put .AddRoute("update", GatewayVerb.PUT, new RouteInfo { Path = "weatherforecast/types/update", RequestType = typeof(UpdateWeatherTypeRequest), ResponseType = typeof(string[]) }) //Patch .AddRoute("patch", GatewayVerb.PATCH, new RouteInfo { Path = "weatherforecast/forecast/patch", ResponseType = typeof(WeatherForecast) }) //Delete .AddRoute("remove", GatewayVerb.DELETE, new RouteInfo { Path = "weatherforecast/types/remove/", ResponseType = typeof(string[]) }) .AddApi("stockservice", "http://localhost:63967/") .AddRoute("stocks", GatewayVerb.GET, new RouteInfo { Path = "stock", ResponseType = typeof(IEnumerable<StockQuote>) }) .AddRoute("stock", GatewayVerb.GET, new RouteInfo { Path = "stock/", ResponseType = typeof(StockQuote) }) .AddHub("chatservice", ConnectionHelpers.BuildHubConnection, "2f85e3c6-66d2-48a3-8ff7-31a65073558b") .AddRoute("room", new HubRouteInfo { InvokeMethod = "SendMessage", ReceiveMethod = "ReceiveMessage", ReceiveParameterTypes = new Type[] { typeof(string), typeof(string) } }); } } ``` * Hook up in Startup.cs ```C# public void ConfigureServices(IServiceCollection services) { services.AddTransient<IWeatherService, WeatherService>(); //Api gateway services.AddApiGateway(); services.AddControllers(); services.AddSwaggerGen(c => { c.SwaggerDoc("v1", new OpenApiInfo { Title = "My Api Gateway", Version = "v1" }); }); } public void Configure(IApplicationBuilder app, IWebHostEnvironment env) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } app.UseSwagger(); app.UseSwaggerUI(c => { c.SwaggerEndpoint("/swagger/v1/swagger.json", "My Api Gateway"); }); //Api gateway app.UseApiGateway(orchestrator => ApiOrchestration.Create(orchestrator, app)); app.UseHttpsRedirection(); app.UseRouting(); app.UseAuthorization(); app.UseEndpoints(endpoints => { //GatewayHub endpoint endpoints.MapHub<GatewayHub>("/gatewayhub"); endpoints.MapControllers(); }); } ``` The Gateway Swagger appears as shown below:  To call the **forecast** Route on the **weather service** Api, you can enter the **Api key** and **Route key** into Swagger as below:  This will hit the **weatherforecast/forecast** endpoint on the backend Weather API. ### Using appsettings.json If you want, you can keep the **ApiKey, RouteKey, backend API base urls and Route path**, in the **appsettings.json**, read it using a Config Service, and pass it to the Api Orchestrator in the Create method. Read [**more**](/Docs/README_ConfigSettings.md). ### Deployment to Prod As with any Web API, when there is any code change, the API Gateway too is published and deployed using **Blue/Green deployment**. This is available in **Azure** & **AWS**. In Azure App Service, you use **deployment slots** etc. * Read [more](https://learn.microsoft.com/en-us/azure/app-service/deploy-best-practices#use-deployment-slots). * Read [more](https://learn.microsoft.com/en-us/azure/container-apps/blue-green-deployment?pivots=azure-cli). Azure Kubernetes Service (AKS) also supports Blue/Green deployment. Read [more](https://learn.microsoft.com/en-us/azure/architecture/guide/aks/blue-green-deployment-for-aks). In AWS, you use **Elastic Beanstalk**. Read [more](https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.CNAMESwap.html). So, there is no down time. ### Verbs usage & Routing You can check out how the Api Gateway supported Verbs are used & Routing below. ### [Verbs Usage & Routing](Docs/README_VERBS.md) ### Authorization Just like a Web API's Authorization Filter, the framework provides a **Gateway Authorization Filter**. Here you can perform any kind of Authorization you like. There is no prescribed Authorization. ### [Authorization](Docs/README_Authorization.md) ### Customizations * Create a new or customize the default **HttpClient** used by all the routes, to hit the backend Api. * Create a new or customize the default **HttpClient** which each route uses to hit the backend Api. * Use your own custom implementation to hit the backend Api. For **Request aggregation**, see this section. ### [Customizations](Docs/README_Customizations.md) ### Load Balancing ### [Load Balancing](Docs/README_LoadBalancing.md) ### Response Caching ### [Response Caching](Docs/README_ResponseCaching.md) ### Web Sockets ### [Web Sockets](Docs/README_WebSockets.md) ### Filters * #### [Action Filters](Docs/README_ActionFilters.md) * #### [Exception Filters](Docs/README_ExceptionFilters.md) * #### [Result Filters](Docs/README_ResultFilters.md) ### Middleware Service ### [Middleware Service](Docs/README_Middleware_Service.md) ### Viewing your Gateway's Api Orchestration Your Gateway's Api Orchestration is published by **GET /api/Gateway/orchestration** endpoint. ### [Viewing Api Orchestration](Docs/README_Orchestration.md) ### Logging The Api Gateway uses **ILogger\<ApiGatewayLog>** to create logs. In your Gateway API project, this can be used to tap into these logs. ## Clients The Api Gateway supports a fixed set of endpoints. All routes go through these endpoints. The Client application has to talk to these endpoints of the Api Gateway. A Client library is provided for: * [**.Net**](Docs/README_Net_Client.md) * [**Typescript**](Docs/README_Typescript_Client.md)", Assign "at most 3 tags" to the expected json: {"id":"8171","tags":[]} "only from the tags list I provide: []" returns me the "expected json"