Add client count to DreamDaemon responses

Closes #1909

build/Version.props

@@ -9,8 +9,8 @@
     <TgsCommonLibraryVersion>7.0.0</TgsCommonLibraryVersion>
     <TgsApiLibraryVersion>13.7.0</TgsApiLibraryVersion>
     <TgsClientVersion>16.0.0</TgsClientVersion>
-    <TgsDmapiVersion>7.2.1</TgsDmapiVersion>
-    <TgsInteropVersion>5.9.0</TgsInteropVersion>
+    <TgsDmapiVersion>7.3.0</TgsDmapiVersion>
+    <TgsInteropVersion>5.10.0</TgsInteropVersion>
     <TgsHostWatchdogVersion>1.5.0</TgsHostWatchdogVersion>
     <TgsContainerScriptVersion>1.2.1</TgsContainerScriptVersion>
     <TgsMigratorVersion>2.0.0</TgsMigratorVersion>

src/DMAPI/tgs.dm

@@ -1,7 +1,7 @@
 // tgstation-server DMAPI
 // The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in IETF RFC 2119.
 
-#define TGS_DMAPI_VERSION "7.2.1"
+#define TGS_DMAPI_VERSION "7.3.0"
 
 // All functions and datums outside this document are subject to change with any version and should not be relied on.
 

src/DMAPI/tgs/v5/__interop_version.dm

@@ -1 +1 @@
-"5.9.0"
+"5.10.0"

src/DMAPI/tgs/v5/_defines.dm

@@ -95,6 +95,7 @@
 #define DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION "newServerVersion"
 #define DMAPI5_TOPIC_PARAMETER_BROADCAST_MESSAGE "broadcastMessage"
 
+#define DMAPI5_TOPIC_RESPONSE_CLIENT_COUNT "clientCount"
 #define DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE "commandResponse"
 #define DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE_MESSAGE "commandResponseMessage"
 #define DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES "chatResponses"

src/DMAPI/tgs/v5/topic.dm

@@ -149,7 +149,9 @@
 		if(DMAPI5_TOPIC_COMMAND_HEALTHCHECK)
 			if(event_handler && event_handler.receive_health_checks)
 				event_handler.HandleEvent(TGS_EVENT_HEALTH_CHECK)
-			return TopicResponse()
+			var/list/health_check_response = TopicResponse()
+			health_check_response[DMAPI5_TOPIC_RESPONSE_CLIENT_COUNT] = TGS_CLIENT_COUNT
+			return health_check_response;
 
 		if(DMAPI5_TOPIC_COMMAND_WATCHDOG_REATTACH)
 			detached = FALSE

src/DMAPI/tgs/v5/undefs.dm

@@ -17,8 +17,8 @@
 #undef DMAPI5_BRIDGE_COMMAND_EVENT
 
 #undef DMAPI5_PARAMETER_ACCESS_IDENTIFIER
+#undef DMAPI5_PARAMETER_CLIENT_COUNT
 #undef DMAPI5_PARAMETER_CUSTOM_COMMANDS
-#undef DMAPI5_PARAMETER_TOPIC_PORT
 
 #undef DMAPI5_CHUNK
 #undef DMAPI5_CHUNK_PAYLOAD
@@ -95,6 +95,7 @@
 #undef DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION
 #undef DMAPI5_TOPIC_PARAMETER_BROADCAST_MESSAGE
 
+#undef DMAPI5_TOPIC_RESPONSE_CLIENT_COUNT
 #undef DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE
 #undef DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE_MESSAGE
 #undef DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES

src/Tgstation.Server.Api/Models/Internal/DreamDaemonApiBase.cs

@@ -19,6 +19,12 @@ namespace Tgstation.Server.Api.Models.Internal
 		[ResponseOptions]
 		public DateTimeOffset? LaunchTime { get; set; }
 
+		/// <summary>
+		/// The last known count of connected players. Requires <see cref="DreamDaemonLaunchParameters.HealthCheckSeconds"/> to not be 0 and a game server interop version >= 5.10.0 to populate.
+		/// </summary>
+		[ResponseOptions]
+		public int? ClientCount { get; set; }
+
 		/// <summary>
 		/// If the server is undergoing a soft reset. This may be automatically set by changes to other fields.
 		/// </summary>

src/Tgstation.Server.Host/Components/Interop/Topic/TopicResponse.cs

@@ -36,5 +36,10 @@ namespace Tgstation.Server.Host.Components.Interop.Topic
 
 		/// <inheritdoc />
 		public IReadOnlyCollection<uint>? MissingChunks { get; set; }
+
+		/// <summary>
+		/// The number of connected clients to the game. Added in Interop 5.10.0.
+		/// </summary>
+		public int? ClientCount { get; }
 	}
 }

src/Tgstation.Server.Host/Components/Watchdog/IWatchdog.cs

@@ -24,6 +24,11 @@ namespace Tgstation.Server.Host.Components.Watchdog
 		/// </summary>
 		DateTimeOffset? LaunchTime { get; }
 
+		/// <summary>
+		/// Last known client count queried from the DMAPI. Requires health checks to be enabled to populate.
+		/// </summary>
+		int? ClientCount { get; }
+
 		/// <summary>
 		/// The current <see cref="WatchdogStatus"/>.
 		/// </summary>

src/Tgstation.Server.Host/Components/Watchdog/WatchdogBase.cs

@@ -38,6 +38,9 @@ namespace Tgstation.Server.Host.Components.Watchdog
 		/// <inheritdoc />
 		public long? SessionId => GetActiveController()?.ReattachInformation.Id;
 
+		/// <inheritdoc />
+		public int? ClientCount { get; private set; }
+
 		/// <inheritdoc />
 		public DateTimeOffset? LaunchTime => GetActiveController()?.LaunchTime;
 
@@ -570,6 +573,7 @@ namespace Tgstation.Server.Host.Components.Watchdog
 			// since neither server is running, this is safe to do
 			LastLaunchParameters = ActiveLaunchParameters;
 			healthChecksMissed = 0;
+			ClientCount = null;
 
 			try
 			{
@@ -667,6 +671,7 @@ namespace Tgstation.Server.Host.Components.Watchdog
 			// we lost the server, just restart entirely
 			// DCT: Operation must always run
 			await DisposeAndNullControllers(CancellationToken.None);
+			ClientCount = null;
 			const string FailReattachMessage = "Unable to properly reattach to server! Restarting watchdog...";
 			Logger.LogWarning(FailReattachMessage);
 
@@ -1183,7 +1188,10 @@ namespace Tgstation.Server.Host.Components.Watchdog
 				}
 			}
 			else
+			{
 				healthChecksMissed = 0;
+				ClientCount = response.ClientCount;
+			}
 
 			return MonitorAction.Continue;
 		}

src/Tgstation.Server.Host/Controllers/DreamDaemonController.cs

@@ -367,6 +367,7 @@ namespace Tgstation.Server.Host.Controllers
 						result.Status = dd.Status;
 						result.SessionId = dd.SessionId;
 						result.LaunchTime = dd.LaunchTime;
+						result.ClientCount = dd.ClientCount;
 					}
 					while (result.Status == WatchdogStatus.Online && !result.SessionId.HasValue); // this is the one invalid combo, it's not that racy
 

tests/Tgstation.Server.Tests/Live/Instance/WatchdogTest.cs

@@ -753,6 +753,9 @@ namespace Tgstation.Server.Tests.Live.Instance
 			Assert.IsTrue(daemonStatus.LaunchTime.HasValue);
 			Assert.IsTrue(daemonStatus.LaunchTime.Value >= DateTimeOffset.UtcNow.AddHours(-1));
 
+			if (daemonStatus.ClientCount.HasValue)
+				Assert.AreEqual(0, daemonStatus.ClientCount.Value);
+
 			if (sessionIdTracker.HasValue)
 				if (knownIncrease.HasValue)
 					if (knownIncrease.Value)
@@ -861,6 +864,8 @@ namespace Tgstation.Server.Tests.Live.Instance
 			// Ensure it's responding to health checks
 			await Task.WhenAny(Task.Delay(7000, cancellationToken), ourProcessHandler.Lifetime);
 			Assert.IsFalse(ddProc.HasExited);
+			var daemonStatus = await instanceClient.DreamDaemon.Read(cancellationToken);
+			Assert.AreEqual(0, daemonStatus.ClientCount);
 
 			// check DD agrees
 			var topicRequestResult = await SendTestTopic(