Adding in-memory heartbeats

Author: johnsimons

src/ServiceControl/Infrastructure/Api/ConfigurationApi.cs

@@ -8,14 +8,15 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Configuration;
+using Monitoring.HeartbeatMonitoring;
 using Particular.ServiceControl.Licensing;
 using ServiceBus.Management.Infrastructure.Settings;
 using ServiceControl.Api;
 using ServiceControl.Api.Contracts;
 
 class ConfigurationApi(ActiveLicense license,
     Settings settings,
-    IHttpClientFactory httpClientFactory) : IConfigurationApi
+    IHttpClientFactory httpClientFactory, MassTransitConnectorHeartbeatStatus connectorHeartbeatStatus) : IConfigurationApi
 {
     public Task<RootUrls> GetUrls(string baseUrl, CancellationToken cancellationToken)
     {
@@ -83,10 +84,7 @@ public Task<object> GetConfig(CancellationToken cancellationToken)
             {
                 settings.HeartbeatGracePeriod
             },
-            MassTransitConnector = new
-            {
-                foobar = "barfoo"
-            }
+            MassTransitConnector = connectorHeartbeatStatus.LastHeartbeat
         };
 
         return Task.FromResult(content);

src/ServiceControl/Monitoring/HeartbeatMonitoring/InternalMessages/MassTransitConnectorHeartbeat.cs

@@ -0,0 +1,27 @@
+namespace ServiceControl.Connector.MassTransit;
+
+using System;
+using NServiceBus;
+
+public class MassTransitConnectorHeartbeat : IMessage
+{
+    public required string Version { get; set; }
+    public required ErrorQueue[] ErrorQueues { get; set; }
+    public required LogEntry[] Logs { get; set; }
+    public required DateTimeOffset SentDateTimeOffset { get; set; }
+}
+
+#pragma warning disable CA1711
+public class ErrorQueue
+#pragma warning restore CA1711
+{
+    public required string Name { get; set; }
+    public required bool Ingesting { get; set; }
+}
+
+public class LogEntry
+{
+    public string Message { get; set; }
+    public DateTimeOffset Date { get; set; }
+    public string Level { get; set; }
+}

src/ServiceControl/Monitoring/HeartbeatMonitoring/MassTransitConnectorHeartbeatStatus.cs

@@ -0,0 +1,11 @@
+#nullable enable
+namespace ServiceControl.Monitoring.HeartbeatMonitoring;
+
+using Connector.MassTransit;
+
+public class MassTransitConnectorHeartbeatStatus
+{
+    public MassTransitConnectorHeartbeat? LastHeartbeat { get; private set; }
+
+    public void Update(MassTransitConnectorHeartbeat lastHeartbeat) => LastHeartbeat = lastHeartbeat;
+}

src/ServiceControl/Monitoring/HeartbeatMonitoringComponent.cs

@@ -4,6 +4,7 @@
     using EndpointControl.Handlers;
     using EventLog;
     using ExternalIntegrations;
+    using HeartbeatMonitoring;
     using Infrastructure.DomainEvents;
     using Microsoft.Extensions.DependencyInjection;
     using Microsoft.Extensions.Hosting;
@@ -21,6 +22,7 @@ public override void Configure(Settings settings, ITransportCustomization transp
             hostBuilder.Services.AddHostedService<HeartbeatEndpointSettingsSyncHostedService>();
 
             hostBuilder.Services.AddSingleton<IEndpointInstanceMonitoring, EndpointInstanceMonitoring>();
+            hostBuilder.Services.AddSingleton<MassTransitConnectorHeartbeatStatus>();
 
             hostBuilder.Services.AddDomainEventHandler<MonitoringDataPersister>();
 

src/ServiceControl/Monitoring/Transport/MassTransitConnectorHeartbeatHandler.cs

@@ -0,0 +1,19 @@
+namespace ServiceControl.Monitoring;
+
+using System.Threading.Tasks;
+using Connector.MassTransit;
+using HeartbeatMonitoring;
+using NServiceBus;
+
+class MassTransitConnectorHeartbeatHandler(MassTransitConnectorHeartbeatStatus connectorHeartbeatStatus) : IHandleMessages<MassTransitConnectorHeartbeat>
+{
+    public Task Handle(MassTransitConnectorHeartbeat message, IMessageHandlerContext context)
+    {
+        if (connectorHeartbeatStatus.LastHeartbeat == null || message.SentDateTimeOffset > connectorHeartbeatStatus.LastHeartbeat.SentDateTimeOffset)
+        {
+            connectorHeartbeatStatus.Update(message);
+        }
+
+        return Task.CompletedTask;
+    }
+}