Make configuration easier

Author: MatthewSteeples

Ledgerscope.PassiveHealthChecker.Sample/Program.cs

@@ -1,5 +1,4 @@
 using Microsoft.Extensions.Diagnostics.HealthChecks;
-using Microsoft.Extensions.Http;
 using System.Text;
 using System.Text.Json;
 
@@ -13,18 +12,7 @@ public static void Main(string[] args)
 
             // Add services to the container.
             builder.Services.AddRazorPages();
-
-            builder.Services.AddSingleton<PassiveHttpHealthCheckStatuses>();
-
-            builder.Services.AddHealthChecks()
-                .AddCheck<PassiveHttpHealthCheckHealthCheck>("Passive Http Health Check");
-
-            // Register the handler
-            builder.Services.AddTransient<PassiveHttpHealthCheckHandler>();
-
-            builder.Services.AddHttpClient();
-
-            builder.Services.AddTransient<IHttpMessageHandlerBuilderFilter, GlobalHttpMessageHandlerBuilderFilter>();
+            builder.Services.ConfigurePassiveHealthChecker();
 
             var app = builder.Build();
 

PassiveHealthChecker/Ledgerscope.PassiveHealthChecker.csproj

@@ -8,6 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Diagnostics.HealthChecks" Version="10.0.5" />
     <PackageReference Include="Microsoft.Extensions.Diagnostics.HealthChecks.Abstractions" Version="10.0.5" />
     <PackageReference Include="Microsoft.Extensions.Http" Version="10.0.5" />
   </ItemGroup>

PassiveHealthChecker/PassiveHealthCheckerServiceCollectionExtensions.cs

@@ -0,0 +1,48 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Diagnostics.HealthChecks;
+using Microsoft.Extensions.Http;
+
+namespace Ledgerscope.PassiveHealthChecker
+{
+    /// <summary>
+    /// Extensions for registering the passive health checker services.
+    /// </summary>
+    public static class PassiveHealthCheckerServiceCollectionExtensions
+    {
+        private const string DefaultHealthCheckName = "Passive Http Health Check";
+
+        /// <summary>
+        /// Registers the passive health checker services, global HTTP handler filter, and health check.
+        /// </summary>
+        public static T ConfigurePassiveHealthChecker<T>(this T services) where T : IServiceCollection
+        {
+            ArgumentNullException.ThrowIfNull(services);
+
+            services.AddHttpClient();
+
+            services.TryAddSingleton<PassiveHttpHealthCheckStatuses>();
+            services.TryAddTransient<PassiveHttpHealthCheckHandler>();
+            services.TryAddTransient<PassiveHttpHealthCheckHealthCheck>();
+            services.TryAddEnumerable(ServiceDescriptor.Transient<IHttpMessageHandlerBuilderFilter, GlobalHttpMessageHandlerBuilderFilter>());
+
+            services.AddHealthChecks();
+            services.Configure<HealthCheckServiceOptions>(options =>
+            {
+                if (options.Registrations.Any(registration => string.Equals(registration.Name, DefaultHealthCheckName, StringComparison.Ordinal)))
+                {
+                    return;
+                }
+
+                options.Registrations.Add(new HealthCheckRegistration(
+                    DefaultHealthCheckName,
+                    serviceProvider => serviceProvider.GetRequiredService<PassiveHttpHealthCheckHealthCheck>(),
+                    failureStatus: null,
+                    tags: null,
+                    timeout: default));
+            });
+
+            return services;
+        }
+    }
+}

README.md

@@ -47,14 +47,7 @@ The solution contains two projects:
 Add the following to your Program.cs or Startup.cs:
 
 ```csharp
-// Register the passive health check services
-builder.Services.AddSingleton<PassiveHttpHealthCheckStatuses>();
-builder.Services.AddTransient<PassiveHttpHealthCheckHandler>();
-builder.Services.AddTransient<IHttpMessageHandlerBuilderFilter, GlobalHttpMessageHandlerBuilderFilter>();
-
-// Add the health check
-builder.Services.AddHealthChecks()
-    .AddCheck<PassiveHttpHealthCheckHealthCheck>("Passive Http Health Check");
+builder.Services.ConfigurePassiveHealthChecker();
 
 // Configure health check endpoint
 app.UseHealthChecks("/health");