Readiness and liveness check.

src/Squidex.Domain.Apps.Entities/Apps/Diagnostics/OrleansAppsHealthCheck.cs

@@ -5,6 +5,7 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Orleans;
@@ -19,6 +20,11 @@ namespace Squidex.Domain.Apps.Entities.Apps.Diagnostics
     {
         private readonly IAppsByNameIndex index;
 
+        public IEnumerable<string> Scopes
+        {
+            get { yield return HealthCheckScopes.Cluster; }
+        }
+
         public OrleansAppsHealthCheck(IGrainFactory grainFactory)
         {
             Guard.NotNull(grainFactory, nameof(grainFactory));

src/Squidex.Infrastructure.GetEventStore/Diagnostics/GetEventStoreHealthCheck.cs

@@ -5,6 +5,7 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using EventStore.ClientAPI;
@@ -15,6 +16,11 @@ namespace Squidex.Infrastructure.Diagnostics
     {
         private readonly IEventStoreConnection connection;
 
+        public IEnumerable<string> Scopes
+        {
+            get { yield return HealthCheckScopes.Node; }
+        }
+
         public GetEventStoreHealthCheck(IEventStoreConnection connection)
         {
             Guard.NotNull(connection, nameof(connection));

src/Squidex.Infrastructure.MongoDb/Diagnostics/MongoDBHealthCheck.cs

@@ -5,6 +5,7 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MongoDB.Driver;
@@ -15,6 +16,11 @@ namespace Squidex.Infrastructure.Diagnostics
     {
         private readonly IMongoDatabase mongoDatabase;
 
+        public IEnumerable<string> Scopes
+        {
+            get { yield return HealthCheckScopes.Node; }
+        }
+
         public MongoDBHealthCheck(IMongoDatabase mongoDatabase)
         {
             Guard.NotNull(mongoDatabase, nameof(mongoDatabase));

src/Squidex.Infrastructure/Diagnostics/GCHealthCheck.cs

@@ -17,6 +17,11 @@ namespace Squidex.Infrastructure.Diagnostics
     {
         private readonly long threshold;
 
+        public IEnumerable<string> Scopes
+        {
+            get { yield return HealthCheckScopes.Node; }
+        }
+
         public GCHealthCheck(IOptions<GCHealthCheckOptions> options)
         {
             Guard.NotNull(options, nameof(options));

src/Squidex.Infrastructure/Diagnostics/HealthCheckScopes.cs

@@ -0,0 +1,16 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+namespace Squidex.Infrastructure.Diagnostics
+{
+    public static class HealthCheckScopes
+    {
+        public const string Any = "*";
+        public const string Node = "node";
+        public const string Cluster = "cluster";
+    }
+}

src/Squidex.Infrastructure/Diagnostics/IHealthCheck.cs

@@ -5,6 +5,7 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -12,6 +13,8 @@ namespace Squidex.Infrastructure.Diagnostics
 {
     public interface IHealthCheck
     {
+        IEnumerable<string> Scopes { get; }
+
         Task<HealthCheckResult> CheckHealthAsync(CancellationToken cancellationToken = default(CancellationToken));
     }
 }

src/Squidex.Infrastructure/Diagnostics/OrleansHealthCheck.cs

@@ -5,6 +5,7 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Orleans;
@@ -16,6 +17,11 @@ namespace Squidex.Infrastructure.Diagnostics
     {
         private readonly IManagementGrain managementGrain;
 
+        public IEnumerable<string> Scopes
+        {
+            get { yield return HealthCheckScopes.Cluster; }
+        }
+
         public OrleansHealthCheck(IGrainFactory grainFactory)
         {
             Guard.NotNull(grainFactory, nameof(grainFactory));

src/Squidex/Config/Domain/InfrastructureServices.cs

@@ -42,6 +42,9 @@ namespace Squidex.Config.Domain
             services.AddSingletonAs<GCHealthCheck>()
                 .As<IHealthCheck>();
 
+            services.AddSingletonAs<OrleansHealthCheck>()
+                .As<IHealthCheck>();
+
             services.AddSingletonAs<HttpContextAccessor>()
                 .As<IHttpContextAccessor>();
 
@@ -51,12 +54,12 @@ namespace Squidex.Config.Domain
             services.AddSingletonAs<DefaultUserResolver>()
                 .As<IUserResolver>();
 
-            services.AddSingletonAs<DefaultXmlRepository>()
-                .As<IXmlRepository>();
-
             services.AddSingletonAs<AssetUserPictureStore>()
                 .As<IUserPictureStore>();
 
+            services.AddSingletonAs<DefaultXmlRepository>()
+                .As<IXmlRepository>();
+
             services.AddTransient(typeof(Lazy<>), typeof(Lazier<>));
         }
     }

src/Squidex/Config/Web/WebExtensions.cs

@@ -5,8 +5,10 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System.Collections.Generic;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.HttpOverrides;
+using Squidex.Infrastructure.Diagnostics;
 using Squidex.Pipeline;
 using Squidex.Pipeline.Diagnostics;
 using Squidex.Pipeline.Robots;
@@ -31,7 +33,20 @@ namespace Squidex.Config.Web
 
         public static IApplicationBuilder UseMyHealthCheck(this IApplicationBuilder app)
         {
-            app.Map("/healthz", builder => builder.UseMiddleware<HealthCheckMiddleware>());
+            app.Map("/readiness", builder =>
+            {
+                builder.UseMiddleware<HealthCheckMiddleware>(HealthCheckScopes.Any);
+            });
+
+            app.Map("/healthz", builder =>
+            {
+                builder.UseMiddleware<HealthCheckMiddleware>(HealthCheckScopes.Node);
+            });
+
+            app.Map("/cluster-healthz", builder =>
+            {
+                builder.UseMiddleware<HealthCheckMiddleware>(HealthCheckScopes.Cluster);
+            });
 
             return app;
         }

src/Squidex/Pipeline/Diagnostics/HealthCheckMiddleware.cs

@@ -17,40 +17,46 @@ using Squidex.Infrastructure.Diagnostics;
 
 namespace Squidex.Pipeline.Diagnostics
 {
-    public sealed class HealthCheckMiddleware : IMiddleware
+    public sealed class HealthCheckMiddleware
     {
         private const string Suffix = "HealthCheck";
         private static readonly TimeSpan Timeout = TimeSpan.FromSeconds(2);
 
         private readonly Dictionary<string, IHealthCheck> healthChecks;
         private readonly JsonSerializerSettings serializerSettings;
+        private readonly RequestDelegate next;
+        private readonly List<string> scopes;
 
-        public HealthCheckMiddleware(IEnumerable<IHealthCheck> healthChecks, JsonSerializerSettings serializerSettings)
+        public HealthCheckMiddleware(IEnumerable<IHealthCheck> healthChecks, JsonSerializerSettings serializerSettings, RequestDelegate next, string scopes)
         {
             Guard.NotNull(healthChecks, nameof(healthChecks));
             Guard.NotNull(serializerSettings, nameof(serializerSettings));
 
             this.healthChecks = healthChecks.ToDictionary(GetName);
+            this.next = next;
+            this.scopes = SplitScopes(scopes);
             this.serializerSettings = serializerSettings;
         }
 
-        public async Task InvokeAsync(HttpContext context, RequestDelegate next)
+        public async Task Invoke(HttpContext context)
         {
             if (CanServeRequest(context.Request))
             {
                 using (var cts = new CancellationTokenSource(Timeout))
                 {
-                    var checks = await Task.WhenAll(healthChecks.Select(x => MakeHealthCheckAsync(x.Key, x.Value, cts.Token)));
+                    var matchingChecks = healthChecks.Where(x => CanUseCheck(x.Value));
+
+                    var results = await Task.WhenAll(matchingChecks.Select(x => MakeHealthCheckAsync(x.Key, x.Value, cts.Token)));
 
                     context.Response.StatusCode = 200;
                     context.Response.Headers.Add("Content-Type", "application/json");
 
-                    if (checks.Any(x => !x.Result.IsHealthy))
+                    if (results.Any(x => !x.Result.IsHealthy))
                     {
                         context.Response.StatusCode = 503;
                     }
 
-                    var response = checks.ToDictionary(x => x.Name, x => x.Result);
+                    var response = results.ToDictionary(x => x.Name, x => x.Result);
 
                     await context.Response.WriteAsync(JsonConvert.SerializeObject(new { status = response }, Formatting.Indented, serializerSettings));
                 }
@@ -61,11 +67,21 @@ namespace Squidex.Pipeline.Diagnostics
             }
         }
 
-        private static bool CanServeRequest(HttpRequest request)
+        private bool CanUseCheck(IHealthCheck check)
+        {
+            return scopes.Count == 0 || check.Scopes.Intersect(scopes).Any();
+        }
+
+        private bool CanServeRequest(HttpRequest request)
         {
             return HttpMethods.IsGet(request.Method) && (request.Path == "/" || string.IsNullOrEmpty(request.Path));
         }
 
+        private static List<string> SplitScopes(string scopes)
+        {
+            return scopes.Split(",").Where(x => x != "*").ToList();
+        }
+
         private static string GetName(IHealthCheck check)
         {
             var name = check.GetType().Name.ToCamelCase();