New: Server pushable health checks

Closes #4116

src/NzbDrone.Core/HealthCheck/HealthCheckService.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using NLog;
 using NzbDrone.Common.Cache;
 using NzbDrone.Common.EnvironmentInfo;
+using NzbDrone.Common.Extensions;
 using NzbDrone.Common.Messaging;
 using NzbDrone.Common.Reflection;
 using NzbDrone.Core.Lifecycle;
@@ -27,6 +28,7 @@ namespace NzbDrone.Core.HealthCheck
         private readonly IProvideHealthCheck[] _startupHealthChecks;
         private readonly IProvideHealthCheck[] _scheduledHealthChecks;
         private readonly Dictionary<Type, IEventDrivenHealthCheck[]> _eventDrivenHealthChecks;
+        private readonly IServerSideNotificationService _serverSideNotificationService;
         private readonly IEventAggregator _eventAggregator;
         private readonly ICacheManager _cacheManager;
         private readonly Logger _logger;
@@ -37,12 +39,14 @@ namespace NzbDrone.Core.HealthCheck
         private bool _isRunningHealthChecksAfterGracePeriod;
 
         public HealthCheckService(IEnumerable<IProvideHealthCheck> healthChecks,
+                                  IServerSideNotificationService serverSideNotificationService,
                                   IEventAggregator eventAggregator,
                                   ICacheManager cacheManager,
                                   IRuntimeInfo runtimeInfo,
                                   Logger logger)
         {
             _healthChecks = healthChecks.ToArray();
+            _serverSideNotificationService = serverSideNotificationService;
             _eventAggregator = eventAggregator;
             _cacheManager = cacheManager;
             _logger = logger;
@@ -74,11 +78,16 @@ namespace NzbDrone.Core.HealthCheck
                 .ToDictionary(g => g.Key, g => g.ToArray());
         }
 
-        private void PerformHealthCheck(IProvideHealthCheck[] healthChecks)
+        private void PerformHealthCheck(IProvideHealthCheck[] healthChecks, bool performServerChecks)
         {
             var results = healthChecks.Select(c => c.Check())
                                        .ToList();
 
+            if (performServerChecks)
+            {
+                results.AddIfNotNull(_serverSideNotificationService.GetServerChecks());
+            }
+
             foreach (var result in results)
             {
                 if (result.Type == HealthCheckResult.Ok)
@@ -110,17 +119,17 @@ namespace NzbDrone.Core.HealthCheck
         {
             if (message.Trigger == CommandTrigger.Manual)
             {
-                PerformHealthCheck(_healthChecks);
+                PerformHealthCheck(_healthChecks, true);
             }
             else
             {
-                PerformHealthCheck(_scheduledHealthChecks);
+                PerformHealthCheck(_scheduledHealthChecks, true);
             }
         }
 
         public void HandleAsync(ApplicationStartedEvent message)
         {
-            PerformHealthCheck(_startupHealthChecks);
+            PerformHealthCheck(_startupHealthChecks, true);
         }
 
         public void HandleAsync(IEvent message)
@@ -137,7 +146,7 @@ namespace NzbDrone.Core.HealthCheck
             {
                 _isRunningHealthChecksAfterGracePeriod = true;
 
-                PerformHealthCheck(_startupHealthChecks);
+                PerformHealthCheck(_startupHealthChecks, false);
 
                 // Update after running health checks so new failure notifications aren't sent 2x.
                 _hasRunHealthChecksAfterGracePeriod = true;
@@ -175,7 +184,7 @@ namespace NzbDrone.Core.HealthCheck
 
             // TODO: Add debounce
 
-            PerformHealthCheck(filteredChecks.ToArray());
+            PerformHealthCheck(filteredChecks.ToArray(), false);
         }
     }
 }

src/NzbDrone.Core/HealthCheck/ServerSideNotificationService.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+using NLog;
+using NzbDrone.Common.Cloud;
+using NzbDrone.Common.EnvironmentInfo;
+using NzbDrone.Common.Http;
+using NzbDrone.Common.Serializer;
+using NzbDrone.Core.Configuration;
+
+namespace NzbDrone.Core.HealthCheck
+{
+    public interface IServerSideNotificationService
+    {
+        public HealthCheck GetServerChecks();
+    }
+
+    public class ServerSideNotificationService : IServerSideNotificationService
+    {
+        private readonly IHttpClient _client;
+        private readonly ISonarrCloudRequestBuilder _cloudRequestBuilder;
+        private readonly IConfigFileProvider _configFileProvider;
+        private readonly Logger _logger;
+
+        public ServerSideNotificationService(IHttpClient client, ISonarrCloudRequestBuilder cloudRequestBuilder, IConfigFileProvider configFileProvider, Logger logger)
+        {
+            _client = client;
+            _cloudRequestBuilder = cloudRequestBuilder;
+            _configFileProvider = configFileProvider;
+            _logger = logger;
+        }
+
+        public HealthCheck GetServerChecks()
+        {
+            var request = _cloudRequestBuilder.Services.Create()
+                .Resource("/notification")
+                .AddQueryParam("version", BuildInfo.Version)
+                .AddQueryParam("os", OsInfo.Os.ToString().ToLowerInvariant())
+                .AddQueryParam("arch", RuntimeInformation.OSArchitecture)
+                .AddQueryParam("branch", _configFileProvider.Branch)
+                .Build();
+
+            try
+            {
+                _logger.Trace("Getting notifications");
+
+                var response = _client.Execute(request);
+                var result = Json.Deserialize<List<ServerNotificationResponse>>(response.Content);
+
+                var checks = result.Select(x => new HealthCheck(GetType(), x.Type, x.Message, x.WikiUrl)).ToList();
+
+                // Only one health check is supported, services returns an ordered list, so use the first one
+                return checks.FirstOrDefault() ?? new HealthCheck(GetType());
+            }
+            catch (Exception ex)
+            {
+                _logger.Error(ex, "Failed to retrieve notifications");
+
+                return new HealthCheck(GetType());
+            }
+        }
+    }
+
+    public class ServerNotificationResponse
+    {
+        public HealthCheckResult Type { get; set; }
+        public string Message { get; set; }
+        public string WikiUrl { get; set; }
+    }
+}