Create a service scope for each ASP.NET health check, correct AddHealthContributor documentation

Author: bart-vmware

src/Common/src/Common/HealthChecks/HealthAggregator.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.Concurrent;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Diagnostics.HealthChecks;
 using Steeltoe.Common.Extensions;
 using MicrosoftHealthCheckResult = Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckResult;
@@ -108,7 +109,10 @@ private static async Task<SteeltoeHealthCheckResult> RunMicrosoftHealthCheckAsyn
 
         try
         {
-            IHealthCheck check = registration.Factory(serviceProvider);
+            // Match the behavior of ASP.NET's HealthCheckService, which creates a scope for each check.
+            await using AsyncServiceScope serviceScope = serviceProvider.CreateAsyncScope();
+
+            IHealthCheck check = registration.Factory(serviceScope.ServiceProvider);
             MicrosoftHealthCheckResult result = await check.CheckHealthAsync(context, cancellationToken);
 
             healthCheckResult.Status = ToHealthStatus(result.Status);

src/Management/src/Endpoint/Actuators/Health/EndpointServiceCollectionExtensions.cs

@@ -76,7 +76,7 @@ private static void RegisterDefaultHealthContributors(IServiceCollection service
     }
 
     /// <summary>
-    /// Adds the specified <see cref="IHealthContributor" /> to the D/I container as a scoped service.
+    /// Adds the specified <see cref="IHealthContributor" /> to the D/I container as a singleton service.
     /// </summary>
     /// <typeparam name="T">
     /// The type of health contributor to add.
@@ -98,7 +98,7 @@ public static IServiceCollection AddHealthContributor<T>(this IServiceCollection
     }
 
     /// <summary>
-    /// Adds the specified <see cref="IHealthContributor" /> to the D/I container as a scoped service.
+    /// Adds the specified <see cref="IHealthContributor" /> to the D/I container as a singleton service.
     /// </summary>
     /// <param name="services">
     /// The <see cref="IServiceCollection" /> to add services to.

src/Management/test/Endpoint.Test/Actuators/Health/HealthAggregationTest.cs

@@ -7,6 +7,7 @@
 using FluentAssertions.Extensions;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.TestHost;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Diagnostics.HealthChecks;
@@ -516,6 +517,58 @@ public async Task Converts_AspNet_health_check_results()
             """);
     }
 
+    [Fact]
+    public async Task Can_use_scoped_AspNet_health_check()
+    {
+        WebApplicationBuilder builder = TestWebApplicationBuilderFactory.CreateDefault(false);
+        builder.Configuration.AddInMemoryCollection(AppSettings);
+        builder.Services.AddDbContext<TestDbContext>(options => options.UseInMemoryDatabase(Guid.NewGuid().ToString()));
+        builder.Services.AddHealthChecks().AddDbContextCheck<TestDbContext>();
+        builder.Services.AddHealthActuator();
+        await using WebApplication host = builder.Build();
+
+        // ReSharper disable once AccessToDisposedClosure
+        Action action = () => host.Services.GetRequiredService<TestDbContext>();
+        action.Should().ThrowExactly<InvalidOperationException>();
+
+        await using (AsyncServiceScope scope = host.Services.CreateAsyncScope())
+        {
+            await using var dbContext = scope.ServiceProvider.GetRequiredService<TestDbContext>();
+            await dbContext.Database.EnsureDeletedAsync(TestContext.Current.CancellationToken);
+            await dbContext.Database.EnsureCreatedAsync(TestContext.Current.CancellationToken);
+        }
+
+        host.MapHealthChecks("/health");
+        await host.StartAsync(TestContext.Current.CancellationToken);
+        using var httpClient = new HttpClient();
+
+        HttpResponseMessage actuatorResponse =
+            await httpClient.GetAsync(new Uri("http://localhost:5000/actuator/health"), TestContext.Current.CancellationToken);
+
+        actuatorResponse.StatusCode.Should().Be(HttpStatusCode.OK);
+
+        string actuatorResponseBody = await actuatorResponse.Content.ReadAsStringAsync(TestContext.Current.CancellationToken);
+
+        actuatorResponseBody.Should().BeJson("""
+            {
+              "status": "UP",
+              "components": {
+                "TestDbContext": {
+                  "status": "UP"
+                }
+              }
+            }
+            """);
+
+        HttpResponseMessage aspNetResponse = await httpClient.GetAsync(new Uri("http://localhost:5000/health"), TestContext.Current.CancellationToken);
+
+        aspNetResponse.StatusCode.Should().Be(HttpStatusCode.OK);
+
+        string aspnetResponseBody = await aspNetResponse.Content.ReadAsStringAsync(TestContext.Current.CancellationToken);
+
+        aspnetResponseBody.Should().Be("Healthy");
+    }
+
     private sealed class AspNetHealthyCheck : IHealthCheck
     {
         public async Task<MicrosoftHealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
@@ -562,4 +615,7 @@ public Task<MicrosoftHealthCheckResult> CheckHealthAsync(HealthCheckContext cont
             throw new InvalidOperationException("test-exception");
         }
     }
+
+    private sealed class TestDbContext(DbContextOptions options)
+        : DbContext(options);
 }

src/Management/test/Endpoint.Test/Steeltoe.Management.Endpoint.Test.csproj

@@ -16,6 +16,7 @@
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="$(MatchTargetFrameworkVersion)" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="$(EntityFrameworkCoreTestVersion)" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="$(EntityFrameworkCoreTestVersion)" />
+    <PackageReference Include="Microsoft.Extensions.Diagnostics.HealthChecks.EntityFrameworkCore" Version="$(EntityFrameworkCoreTestVersion)" />
   </ItemGroup>
 
   <ItemGroup>