feat: add heartbeat feature

Detect heartbeat status every 5 seconds. If no heartbeat is received within 5 seconds, the program will exit automatically.

Author: wen2so

OdbDesignServer/Controllers/HealthCheckController.cpp

@@ -22,6 +22,7 @@ namespace Odb::App::Server
 		register_route_handler("/healthz/live", std::bind(&HealthCheckController::health_check_live, this, std::placeholders::_1));
 		register_route_handler("/healthz/ready", std::bind(&HealthCheckController::health_check_ready, this, std::placeholders::_1));
 		register_route_handler("/healthz/started", std::bind(&HealthCheckController::health_check_started, this, std::placeholders::_1));
+        register_route_handler("/healthz/heartbeat", std::bind(&HealthCheckController::health_check_heartbeat, this, std::placeholders::_1));
 	}
 
 	crow::response HealthCheckController::health_check_live(const crow::request& req)
@@ -38,4 +39,11 @@ namespace Odb::App::Server
 	{		
 		return crow::response(crow::status::OK, "txt", "healthy: started");
 	}
+
+	crow::response HealthCheckController::health_check_heartbeat(const crow::request& req)
+	{
+        // update last heartbeat
+        OdbDesignServerApp::inst_->updateLastHeartbeat();
+		return crow::response(crow::status::OK, "txt", "heartbeat received");
+	}
 }

OdbDesignServer/Controllers/HealthCheckController.h

@@ -18,6 +18,7 @@ namespace Odb::App::Server
 		crow::response health_check_live(const crow::request& req);
 		crow::response health_check_ready(const crow::request& req);
 		crow::response health_check_started(const crow::request& req);
+		crow::response health_check_heartbeat(const crow::request& req);
 
 	};
 }

OdbDesignServer/OdbDesignServerApp.cpp

@@ -1,3 +1,6 @@
+#include <thread>
+#include <chrono>
+#include <iostream>
 #include "OdbDesignServerApp.h"
 #include "Controllers/HelloWorldController.h"
 #include "Controllers/FileUploadController.h"
@@ -11,9 +14,13 @@ using namespace Odb::Lib::App;
 
 namespace Odb::App::Server
 {
+	OdbDesignServerApp* OdbDesignServerApp::inst_ = nullptr;
 	OdbDesignServerApp::OdbDesignServerApp(int argc, char* argv[])
 		: OdbServerAppBase(argc, argv)
-	{		
+	{
+		inst_ = this;
+		// set last heartbeat time to now
+		lastHeartbeat_.store(std::chrono::steady_clock::now(), std::memory_order_relaxed);
 	}
 
 	//OdbDesignServerApp::~OdbDesignServerApp()
@@ -44,6 +51,24 @@ namespace Odb::App::Server
 		m_vecControllers.push_back(std::make_shared<DesignsController>(*this));
 	}
 
+	void monitorHeartbeat()
+	{
+		auto lastTime = OdbDesignServerApp::inst_->lastHeartbeat_.load(std::memory_order_relaxed);
+		while (true)
+		{
+			std::this_thread::sleep_for(std::chrono::seconds(1));
+			auto now = std::chrono::steady_clock::now();
+			auto diff = now - lastTime;
+			// check heartbeat
+			if (diff > std::chrono::seconds(5))
+			{
+				std::cerr << "Heartbeat timeout, exiting..." << std::endl;
+				exit(0);
+			}
+			lastTime = OdbDesignServerApp::inst_->lastHeartbeat_.load(std::memory_order_relaxed);
+		}
+	}
+
 	bool OdbDesignServerApp::preServerRun()
 	{
 		// CORS
@@ -70,6 +95,10 @@ namespace Odb::App::Server
 		auto basicRequestAuth = std::make_unique<BasicRequestAuthentication>(BasicRequestAuthentication(disableAuth));
 		request_auth(std::move(basicRequestAuth));
 
+		// start heart beat monitor
+		std::thread heartbeatMonitor(monitorHeartbeat);
+		heartbeatMonitor.detach(); // run in background
+
 		return true;
 	}
 }

OdbDesignServer/OdbDesignServerApp.h

@@ -14,7 +14,15 @@ namespace Odb::App::Server
 
 		//Utils::ExitCode Run() override;		
 
-	protected:												
+		static OdbDesignServerApp* inst_;
+		// store last heartbeat time
+		std::atomic<std::chrono::steady_clock::time_point> lastHeartbeat_;
+		void updateLastHeartbeat()
+		{
+			lastHeartbeat_.store(std::chrono::steady_clock::now(), std::memory_order_relaxed);
+		}
+
+	protected:
 		void add_controllers() override;
 
 

swagger/odbdesign-server-0.9-swagger.yaml

@@ -606,6 +606,13 @@ paths:
         "200":
           description: "" 
   /healthz/ready:
+    get:
+      tags: ["health check"]
+      parameters: []
+      responses:
+        "200":
+          description: ""
+  /healthz/heartbeat:
     get:
       tags: ["health check"]
       parameters: []