Add KubernetesProbesOptionsValidator to ensure different ports for probes

src/Libraries/Microsoft.Extensions.Diagnostics.Probes/KubernetesProbesExtensions.cs

@@ -47,6 +47,10 @@ public static IServiceCollection AddKubernetesProbes(this IServiceCollection ser
         _ = Throw.IfNull(services);
         _ = Throw.IfNull(configure);
 
+        _ = services
+            .AddOptionsWithValidateOnStart<KubernetesProbesOptions, KubernetesProbesOptionsValidator>()
+            .Configure(configure);
+
         var wrapperOptions = new KubernetesProbesOptions();
 
         return services

src/Libraries/Microsoft.Extensions.Diagnostics.Probes/KubernetesProbesOptionsValidator.cs

@@ -0,0 +1,23 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.Extensions.Options;
+
+namespace Microsoft.Extensions.Diagnostics.Probes;
+
+internal sealed class KubernetesProbesOptionsValidator : IValidateOptions<KubernetesProbesOptions>
+{
+    public ValidateOptionsResult Validate(string? name, KubernetesProbesOptions options)
+    {
+        var builder = new ValidateOptionsResultBuilder();
+
+        if (options.LivenessProbe.TcpPort == options.StartupProbe.TcpPort
+            || options.LivenessProbe.TcpPort == options.ReadinessProbe.TcpPort
+            || options.StartupProbe.TcpPort == options.ReadinessProbe.TcpPort)
+        {
+            builder.AddError("Liveness, startup and readiness probes must use different ports.");
+        }
+
+        return builder.Build();
+    }
+}

test/Libraries/Microsoft.Extensions.Diagnostics.Probes.Tests/KubernetesProbesOptionsValidatorTests.cs

@@ -0,0 +1,124 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Options;
+using Xunit;
+
+namespace Microsoft.Extensions.Diagnostics.Probes.Test;
+
+public class KubernetesProbesOptionsValidatorTests
+{
+    [Fact]
+    public void Validator_DefaultValues_Succeeds()
+    {
+        var options = new KubernetesProbesOptions();
+        ValidateOptionsResult result = new KubernetesProbesOptionsValidator().Validate(nameof(options), options);
+
+        Assert.True(result.Succeeded);
+    }
+
+    [Fact]
+    public void Validator_GivenValidOptions_Succeeds()
+    {
+        var options = new KubernetesProbesOptions();
+        options.LivenessProbe.TcpPort = 2305;
+        options.StartupProbe.TcpPort = 2306;
+        options.ReadinessProbe.TcpPort = 2307;
+
+        ValidateOptionsResult result = new KubernetesProbesOptionsValidator().Validate(nameof(options), options);
+
+        Assert.True(result.Succeeded);
+    }
+
+    [Fact]
+    public void Validator_GivenInvalidOptions_Fails()
+    {
+        var options = new KubernetesProbesOptions();
+        options.LivenessProbe.TcpPort = 2305;
+        options.StartupProbe.TcpPort = 2305;
+        options.ReadinessProbe.TcpPort = 2307;
+
+        var validator = new KubernetesProbesOptionsValidator();
+        ValidateOptionsResult result = validator.Validate(nameof(options), options);
+        Assert.True(result.Failed);
+
+        options.LivenessProbe.TcpPort = 2305;
+        options.StartupProbe.TcpPort = 2306;
+        options.ReadinessProbe.TcpPort = 2305;
+        result = validator.Validate(nameof(options), options);
+        Assert.True(result.Failed);
+
+        options.LivenessProbe.TcpPort = 2305;
+        options.StartupProbe.TcpPort = 2306;
+        options.ReadinessProbe.TcpPort = 2306;
+        result = validator.Validate(nameof(options), options);
+        Assert.True(result.Failed);
+
+        options.LivenessProbe.TcpPort = 2305;
+        options.StartupProbe.TcpPort = 2305;
+        options.ReadinessProbe.TcpPort = 2305;
+        result = validator.Validate(nameof(options), options);
+        Assert.True(result.Failed);
+    }
+
+    [Fact]
+    public async Task Validator_WhenHostStarts_Succeeds()
+    {
+        using IHost host = CreateHost(services =>
+        {
+            services.AddKubernetesProbes(options =>
+            {
+                options.LivenessProbe.TcpPort = 22305;
+                options.StartupProbe.TcpPort = 22306;
+                options.ReadinessProbe.TcpPort = 22307;
+            }).AddHealthChecks();
+        });
+
+        try
+        {
+            host.Start();
+            await host.StopAsync();
+        }
+        catch (OptionsValidationException ex)
+        {
+            Assert.Fail("Unexpected OptionsValidationException: " + ex.Message);
+        }
+        catch (Exception ex)
+        {
+            Assert.Fail("Unexpected exception: " + ex.Message);
+            throw;
+        }
+    }
+
+    [Fact]
+    public void Validator_WhenHostStarts_Fails()
+    {
+        Action action = () =>
+        {
+            using IHost host = CreateHost(services =>
+            {
+                services.AddKubernetesProbes(options =>
+                {
+                    options.LivenessProbe.TcpPort = 22305;
+                    options.StartupProbe.TcpPort = 22305;
+                    options.ReadinessProbe.TcpPort = 22307;
+                }).AddHealthChecks();
+            });
+
+            host.Start();
+        };
+
+        Assert.Throws<OptionsValidationException>(action);
+    }
+
+    private static IHost CreateHost(Action<IServiceCollection> configureServices)
+    {
+        return Host.CreateDefaultBuilder()
+            .ConfigureServices(configureServices)
+            .Build();
+    }
+}