health check changes

Author: HaikAsatryan

Readme.md

@@ -24,8 +24,8 @@ This package currently supports:
 - **Resilience Pipelines** for `HttpClient` operations.
 - **Controller Extensions** for mapping old-style MVC controllers.
 - **SignalR Extensions** for adding simple SignalR or distributed SignalR backed with Redis.
-- **OpenTelemetry Integration** for tracking metrics, traces, and logging.
-- **Health Checks** with default endpoints and startup validation.
+- **OpenTelemetry**: Metrics, traces, and logs with Prometheus support.
+- **Health Checks**: Startup validation and endpoints for monitoring.
 - Various **Extensions and Utilities**, including enumerable, string, and queryable extensions.
 
 ## Prerequisites
@@ -162,8 +162,9 @@ app
    .UseResponseCrafter()
    .UseCors()
    .MapMinimalApis()
-   .MapDefaultEndpoints()
    .EnsureHealthy()
+   .MapHealthCheckEndpoints()
+   .MapPrometheusExporterEndpoints()
    .ClearAssemblyRegistry()
    .UseOpenApi()
    .MapControllers();
@@ -422,7 +423,7 @@ The package includes extension methods to simplify common validation scenarios:
 - File Validations:
     - HasMaxFileSize(maxFileSizeInMb): Validates that an uploaded file does not exceed the specified maximum size.
     - FileTypeIsOneOf(allowedFileExtensions): Validates that the uploaded file has one of the allowed file
-          extensions.
+      extensions.
 - String Validations:
     - IsValidJson(): Validates that a string is a valid JSON.
     - IsXssSanitized(): Validates that a string is sanitized against XSS attacks.
@@ -545,45 +546,43 @@ app.MapControllers();
 app.Run();
 ```
 
-## OpenTelemetry
+## Telemetry Integration
 
-Use `builder.AddOpenTelemetry()` to add OpenTelemetry to your project. This will track metrics, traces, and logging at
-runtime, including ASP.NET Core and `HttpClient` operations.
-
-Example:
-
-```csharp
-var builder = WebApplication.CreateBuilder(args);
-builder.AddOpenTelemetry();
-```
+Integrate OpenTelemetry for observability, including metrics, traces, and logging:
+1. Setup:
+    ```csharp
+    var builder = WebApplication.CreateBuilder(args);
+    builder.AddOpenTelemetry();
+    var app = builder.Build();
+    app.MapPrometheusExporterEndpoints();
+    app.Run();
+    ```
+2. Prometheus Endpoints:
+    - Metrics: `url/above-board/metrics`
+    - Health Metrics: `url/above-board/metrics/health`
+3. Included Features:
+    - ASP.NET Core metrics
+    - HTTP client telemetry
+    - Distributed tracing
+    - Logging
+    - Prometheus exporter
 
 ## HealthChecks
-
-The `app.EnsureHealthy()` extension method performs a health check at startup and will terminate the application if it
-is not healthy.
+- **Startup Validation:** `app.EnsureHealthy()` performs a health check at startup and terminates the application if it
+  is not healthy.
+- **Endpoints Mapping:** `app.MapHealthCheckEndpoints()` maps default health check endpoints to the application.
+- **Mapped Endpoints:**
+  - Ping Endpoint: `url/above-board/ping`
+  - Health Check Endpoint: `url/above-board/health`
 
 Example:
-
 ```csharp
 var app = builder.Build();
-app.EnsureHealthy();
-```
-
-### Default Endpoints
-
-To map default endpoints, use `app.MapDefaultEndpoints()`. This will add the following endpoints:
-
-- Ping Endpoint: `url/above-board/ping`
-- Health Check Endpoint: `url/above-board/health`
-- Prometheus Metrics Endpoint: `url/above-board/metrics`
-- Prometheus Health Metrics Endpoint: `url/above-board/metrics/health`
 
-> Note: To use Prometheus endpoints, you need to apply `OpenTelemetry` as well.
+app.EnsureHealthy(); // Startup validation
+app.MapHealthCheckEndpoints(); // Map health check routes
 
-Example:
-
-```csharp
-app.MapDefaultEndpoints();
+app.Run();
 ```
 
 ## Additional Extensions and NuGet Packages

src/SharedKernel/Constants/EndpointConstants.cs

@@ -0,0 +1,7 @@
+namespace SharedKernel.Constants;
+
+internal static class EndpointConstants
+{
+   internal const string TagName = "above-board";
+   internal const string BasePath = $"/{TagName}";
+}

src/SharedKernel/Extensions/DefaultEndpoints.cs

@@ -1,7 +1,11 @@
-using Microsoft.AspNetCore.Builder;
+using HealthChecks.UI.Client;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Diagnostics.HealthChecks;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Diagnostics.HealthChecks;
 using ResponseCrafter.HttpExceptions;
+using SharedKernel.Constants;
 
 namespace SharedKernel.Extensions;
 
@@ -48,4 +52,21 @@ public static WebApplicationBuilder AddHealthChecks(this WebApplicationBuilder b
       builder.Services.AddHealthChecks();
       return builder;
    }
+
+   public static WebApplication MapHealthCheckEndpoints(this WebApplication app)
+   {
+      app
+         .MapGet($"{EndpointConstants.BasePath}/ping", () => "pong")
+         .Produces<string>()
+         .WithTags(EndpointConstants.TagName)
+         .WithOpenApi();
+
+      app.MapHealthChecks($"{EndpointConstants.BasePath}/health",
+         new HealthCheckOptions
+         {
+            ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse
+         });
+
+      return app;
+   }
 }

src/SharedKernel/Extensions/HealthCheckExtensions.cs

@@ -1,9 +1,12 @@
+using System.Net;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Diagnostics.HealthChecks;
 using Microsoft.Extensions.Logging;
 using OpenTelemetry.Metrics;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
+using SharedKernel.Constants;
 
 namespace SharedKernel.Extensions;
 
@@ -35,4 +38,14 @@ public static WebApplicationBuilder AddOpenTelemetry(this WebApplicationBuilder
 
       return builder;
    }
+
+   public static WebApplication MapPrometheusExporterEndpoints(this WebApplication app)
+   {
+      app.MapPrometheusScrapingEndpoint($"{EndpointConstants.BasePath}/metrics");
+
+      app.UseHealthChecksPrometheusExporter($"{EndpointConstants.BasePath}/metrics/health",
+         options => options.ResultStatusCodes[HealthStatus.Unhealthy] = (int)HttpStatusCode.OK);
+
+      return app;
+   }
 }

src/SharedKernel/Extensions/OpenTelemetryExtension.cs

@@ -8,13 +8,13 @@
         <PackageReadmeFile>Readme.md</PackageReadmeFile>
         <Authors>Pandatech</Authors>
         <Copyright>MIT</Copyright>
-        <Version>1.0.2</Version>
+        <Version>1.0.3</Version>
         <PackageId>Pandatech.SharedKernel</PackageId>
         <Title>Pandatech Shared Kernel Library</Title>
         <PackageTags>Pandatech, shared kernel, library, OpenAPI, Swagger, utilities, scalar</PackageTags>
         <Description>Pandatech.SharedKernel provides centralized configurations, utilities, and extensions for ASP.NET Core projects. For more information refere to readme.md document.</Description>
         <RepositoryUrl>https://github.com/PandaTechAM/be-lib-sharedkernel</RepositoryUrl>
-        <PackageReleaseNotes>Added redis and signalR utils</PackageReleaseNotes>
+        <PackageReleaseNotes>Healthcheck implementation changes</PackageReleaseNotes>
     </PropertyGroup>
 
     <ItemGroup>
@@ -42,7 +42,7 @@
         <PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.9.0"/>
         <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.9.0"/>
         <PackageReference Include="Pandatech.Crypto" Version="4.0.0" />
-        <PackageReference Include="Pandatech.DistributedCache" Version="3.0.0" />
+        <PackageReference Include="Pandatech.DistributedCache" Version="3.0.1" />
         <PackageReference Include="Pandatech.FluentMinimalApiMapper" Version="2.0.1" />
         <PackageReference Include="Pandatech.PandaVaultClient" Version="4.0.0" />
         <PackageReference Include="Pandatech.RegexBox" Version="3.0.0" />

src/SharedKernel/SharedKernel.csproj

@@ -41,7 +41,8 @@
    .UseResponseCrafter()
    .UseCors()
    .MapMinimalApis()
-   .MapDefaultEndpoints()
+   .MapHealthCheckEndpoints()
+   .MapPrometheusExporterEndpoints()
    .EnsureHealthy()
    .ClearAssemblyRegistry()
    .UseOpenApi()