add-health-check-for-event-grid

src/HealthChecks.Azure.Messaging.EventGrid/AzureEventGridHealthCheck.cs

@@ -0,0 +1,33 @@
+namespace HealthChecks.Azure.Messaging.EventGrid;
+
+public sealed class AzureEventGridHealthCheck : IHealthCheck
+{
+    private readonly EventGridPublisherClient _client;
+
+    public AzureEventGridHealthCheck(EventGridPublisherClient client)
+    {
+        _client = Guard.ThrowIfNull(client);
+    }
+
+    /// <inheritdoc />
+    public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            // Send a ping event to verify connectivity
+            var healthCheckEvent = new EventGridEvent(
+                "HealthCheck",
+                "HealthCheck.Ping",
+                "1.0",
+                new { Timestamp = DateTimeOffset.UtcNow });
+
+            await _client.SendEventAsync(healthCheckEvent, cancellationToken).ConfigureAwait(false);
+
+            return HealthCheckResult.Healthy();
+        }
+        catch (Exception ex)
+        {
+            return new HealthCheckResult(context.Registration.FailureStatus, exception: ex);
+        }
+    }
+}

src/HealthChecks.Azure.Messaging.EventGrid/DependencyInjection/AzureEventGridHealthChecksBuilderExtensions.cs

@@ -0,0 +1,41 @@
+namespace Microsoft.Extensions.DependencyInjection;
+
+/// <summary>
+/// Extension methods to configure <see cref="AzureEventGridHealthCheck"/>.
+/// </summary>
+public static class AzureEventGridHealthChecksBuilderExtensions
+{
+    private const string NAME = "azure_event_grid";
+
+    /// <summary>
+    /// Add a health check for Azure Event Grid by registering <see cref="AzureEventGridHealthCheck"/> for given <paramref name="builder"/>.
+    /// </summary>
+    /// <param name="builder">The <see cref="IHealthChecksBuilder"/> to add <see cref="HealthCheckRegistration"/> to.</param>
+    /// <param name="clientFactory">
+    /// An optional factory to obtain <see cref="EventGridPublisherClient" /> instance.
+    /// When not provided, <see cref="EventGridPublisherClient" /> is simply resolved from <see cref="IServiceProvider"/>.
+    /// </param>
+    /// <param name="name">The health check name. Optional. If <c>null</c> the name 'azure_event_grid' will be used.</param>
+    /// <param name="failureStatus">
+    /// The <see cref="HealthStatus"/> that should be reported when the health check fails. Optional. If <c>null</c> then
+    /// the default status of <see cref="HealthStatus.Unhealthy"/> will be reported.
+    /// </param>
+    /// <param name="tags">A list of tags that can be used to filter sets of health checks. Optional.</param>
+    /// <param name="timeout">An optional <see cref="TimeSpan"/> representing the timeout of the check.</param>
+    /// <returns>The specified <paramref name="builder"/>.</returns>
+    public static IHealthChecksBuilder AddAzureEventGrid(
+        this IHealthChecksBuilder builder,
+        Func<IServiceProvider, EventGridPublisherClient>? clientFactory = default,
+        string? name = NAME,
+        HealthStatus? failureStatus = default,
+        IEnumerable<string>? tags = default,
+        TimeSpan? timeout = default)
+    {
+        return builder.Add(new HealthCheckRegistration(
+           name ?? NAME,
+           sp => new AzureEventGridHealthCheck(clientFactory?.Invoke(sp) ?? sp.GetRequiredService<EventGridPublisherClient>()),
+           failureStatus,
+           tags,
+           timeout));
+    }
+}

src/HealthChecks.Azure.Messaging.EventGrid/GlobalUsings.cs

@@ -0,0 +1,9 @@
+global using System;
+global using System.Threading;
+global using System.Threading.Tasks;
+global using System.Runtime.CompilerServices;
+
+global using Azure.Messaging.EventGrid;
+
+global using Microsoft.Extensions.DependencyInjection;
+global using Microsoft.Extensions.Diagnostics.HealthChecks;

src/HealthChecks.Azure.Messaging.EventGrid/HealthChecks.Azure.Messaging.EventGrid.csproj

@@ -0,0 +1,16 @@
+<![CDATA[<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>net6.0;net7.0;net8.0</TargetFrameworks>
+    <PackageTags>$(PackageTags);Azure;EventGrid</PackageTags>
+    <Description>HealthChecks.Azure.Messaging.EventGrid is the health check package for Azure Event Grid.</Description>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.Messaging.EventGrid" />
+    <PackageReference Include="Microsoft.Extensions.Diagnostics.HealthChecks" />
+  </ItemGroup>
+
+</Project>]]>

src/HealthChecks.Azure.Messaging.EventGrid/README.md

@@ -0,0 +1,51 @@
+# Azure Event Grid Health Check
+
+This health check verifies the ability to communicate with [Azure Event Grid](https://azure.microsoft.com/services/event-grid/). It uses the provided [EventGridPublisherClient](https://learn.microsoft.com/dotnet/api/azure.messaging.eventgrid.eventgridpublisherclient) to send a ping event to verify connectivity.
+
+## Implementation
+
+The health check makes an actual call to Event Grid by sending a simple ping event. This verifies that:
+1. The client is properly configured
+2. The connection to Event Grid service is working
+3. The topic exists and is accessible
+4. The credentials are valid and not expired
+
+## Setup
+
+```csharp
+public void ConfigureServices(IServiceCollection services)
+{
+    // Register the EventGridPublisherClient
+    services.AddSingleton(sp =>
+    {
+        return new EventGridPublisherClient(
+            new Uri("https://<your-topic-endpoint>"),
+            new AzureKeyCredential("<your-access-key>"));
+    });
+
+    services
+        .AddHealthChecks()
+        .AddAzureEventGrid();
+}
+```
+
+You can also register the health check by providing a factory method for the client:
+
+```csharp
+services
+    .AddHealthChecks()
+    .AddAzureEventGrid(sp =>
+    {
+        return new EventGridPublisherClient(
+            new Uri("https://<your-topic-endpoint>"),
+            new AzureKeyCredential("<your-access-key>"));
+    });
+```
+
+## Parameters
+
+- `clientFactory`: An optional factory to obtain the EventGridPublisherClient instance. When not provided, EventGridPublisherClient is resolved from IServiceProvider.
+- `name`: The health check name. Optional. If null the name 'azure_event_grid' will be used.
+- `failureStatus`: The HealthStatus that should be reported when the health check fails. Optional. If null then the default status of HealthStatus.Unhealthy will be reported.
+- `tags`: A list of tags that can be used to filter sets of health checks.
+- `timeout`: An optional TimeSpan representing the timeout of the check.

src/HealthChecks.Azure.Messaging.EventGrid/Utils/Guard.cs

@@ -0,0 +1,15 @@
+namespace HealthChecks.Azure.Messaging.EventGrid;
+
+internal static class Guard
+{
+    public static T ThrowIfNull<T>(T value, [CallerArgumentExpression(nameof(value))] string? parameterName = null)
+        where T : class
+    {
+        if (value is null)
+        {
+            throw new ArgumentNullException(parameterName);
+        }
+
+        return value;
+    }
+}

test/HealthChecks.Azure.Messaging.EventGrid.Tests/EventGridConformanceTests.cs

@@ -0,0 +1,24 @@
+using Azure.Identity;
+using Azure.Messaging.EventGrid;
+
+namespace HealthChecks.Azure.Messaging.EventGrid.Tests;
+
+public class EventGridConformanceTests : ConformanceTests<EventGridPublisherClient, AzureEventGridHealthCheck, UnusedOptions>
+{
+    protected override IHealthChecksBuilder AddHealthCheck(IHealthChecksBuilder builder, Func<IServiceProvider, EventGridPublisherClient>? clientFactory = null, Func<IServiceProvider, UnusedOptions>? optionsFactory = null, string? healthCheckName = null, HealthStatus? failureStatus = null, IEnumerable<string>? tags = null, TimeSpan? timeout = null)
+        => builder.AddAzureEventGrid(clientFactory, healthCheckName, failureStatus, tags, timeout);
+
+    protected override EventGridPublisherClient CreateClientForNonExistingEndpoint()
+        => new(new Uri("https://non-existing-topic.region.eventgrid.azure.net"), new AzureCliCredential());
+
+    protected override AzureEventGridHealthCheck CreateHealthCheck(EventGridPublisherClient client, UnusedOptions? options)
+        => new(client);
+
+    protected override UnusedOptions CreateHealthCheckOptions()
+        => new();
+}
+
+// AzureEventGridHealthCheck does not use any options, the type exists only to meet ConformanceTests<,,> criteria
+public sealed class UnusedOptions
+{
+}

test/HealthChecks.Azure.Messaging.EventGrid.Tests/GlobalUsings.cs

@@ -0,0 +1,9 @@
+global using System;
+global using System.Threading;
+global using System.Threading.Tasks;
+global using System.Collections.Generic;
+
+global using Microsoft.Extensions.DependencyInjection;
+global using Microsoft.Extensions.Diagnostics.HealthChecks;
+
+global using HealthChecks.Tests.Common;

test/HealthChecks.Azure.Messaging.EventGrid.Tests/HealthChecks.Azure.Messaging.EventGrid.Tests.csproj

@@ -0,0 +1,27 @@
+<![CDATA[<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <IsPackable>false</IsPackable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.Identity" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="PublicApiGenerator" />
+    <PackageReference Include="Shouldly" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\HealthChecks.Azure.Messaging.EventGrid\HealthChecks.Azure.Messaging.EventGrid.csproj" />
+    <ProjectReference Include="..\HealthChecks.Tests.Common\HealthChecks.Tests.Common.csproj" />
+  </ItemGroup>
+
+</Project>]]>

test/HealthChecks.Azure.Messaging.EventGrid.Tests/HealthChecks.Azure.Messaging.EventGrid.approved.txt

@@ -0,0 +1,15 @@
+namespace HealthChecks.Azure.Messaging.EventGrid
+{
+    public sealed class AzureEventGridHealthCheck : Microsoft.Extensions.Diagnostics.HealthChecks.IHealthCheck
+    {
+        public AzureEventGridHealthCheck(Azure.Messaging.EventGrid.EventGridPublisherClient client) { }
+        public System.Threading.Tasks.Task<Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckResult> CheckHealthAsync(Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckContext context, System.Threading.CancellationToken cancellationToken = default) { }
+    }
+}
+namespace Microsoft.Extensions.DependencyInjection
+{
+    public static class AzureEventGridHealthChecksBuilderExtensions
+    {
+        public static Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder AddAzureEventGrid(this Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder builder, System.Func<System.IServiceProvider, Azure.Messaging.EventGrid.EventGridPublisherClient>? clientFactory = null, string? name = "azure_event_grid", Microsoft.Extensions.Diagnostics.HealthChecks.HealthStatus? failureStatus = default, System.Collections.Generic.IEnumerable<string>? tags = null, System.TimeSpan? timeout = default) { }
+    }
+}