Extended Health endpoint with support for returning build version and log file.

2 files changed, 129 insertions, 12 deletions

diff --git a/zenserver/diag/diagsvcs.cpp b/zenserver/diag/diagsvcs.cpp
new file mode 100644
index 000000000..edd9b782e
--- /dev/null
+++ b/zenserver/diag/diagsvcs.cpp
@@ -0,0 +1,113 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include "diagsvcs.h"
+
+#include <zencore/compactbinary.h>
+#include <zencore/compactbinarybuilder.h>
+#include <zencore/filesystem.h>
+#include <zencore/logging.h>
+#include <zencore/string.h>
+#include <fstream>
+#include <sstream>
+
+#include <json11.hpp>
+
+namespace zen {
+
+using namespace std::literals;
+
+bool
+ReadFile(const std::string& Path, StringBuilderBase& Out)
+{
+	try
+	{
+		constexpr auto ReadSize	  = std::size_t{4096};
+		auto		   FileStream = std::ifstream{Path};
+
+		std::string Buf(ReadSize, '\0');
+		while (FileStream.read(&Buf[0], ReadSize))
+		{
+			Out.Append(std::string_view(&Buf[0], FileStream.gcount()));
+		}
+		Out.Append(std::string_view(&Buf[0], FileStream.gcount()));
+
+		return true;
+	}
+	catch (std::exception&)
+	{
+		Out.Reset();
+		return false;
+	}
+}
+
+HttpHealthService::HttpHealthService()
+{
+	m_Router.RegisterRoute(
+		"",
+		[this](HttpRouterRequest& RoutedReq) {
+			HttpServerRequest& HttpReq = RoutedReq.ServerRequest();
+			HttpReq.WriteResponse(HttpResponseCode::OK, HttpContentType::kText, u8"OK!"sv);
+		},
+		HttpVerb::kGet);
+
+	m_Router.RegisterRoute(
+		"info",
+		[this](HttpRouterRequest& RoutedReq) {
+			HttpServerRequest& HttpReq = RoutedReq.ServerRequest();
+
+			CbObjectWriter Writer;
+			Writer << "DataRoot"sv << m_HealthInfo.DataRoot.string();
+			Writer << "AbsLogPath"sv << m_HealthInfo.AbsLogPath.string();
+			Writer << "BuildVersion"sv << m_HealthInfo.BuildVersion;
+			Writer << "HttpServerClass"sv << m_HealthInfo.HttpServerClass;
+
+			ExtendableStringBuilder<256> Sb;
+			HttpReq.WriteResponse(HttpResponseCode::OK, HttpContentType::kJSON, Writer.Save().ToJson(Sb).ToView());
+		},
+		HttpVerb::kGet);
+
+	m_Router.RegisterRoute(
+		"log",
+		[this](HttpRouterRequest& RoutedReq) {
+			HttpServerRequest& HttpReq = RoutedReq.ServerRequest();
+
+			zen::Log().flush();
+
+			std::filesystem::path Path =
+				m_HealthInfo.AbsLogPath.empty() ? m_HealthInfo.DataRoot / "logs/zenserver.log" : m_HealthInfo.AbsLogPath;
+
+			ExtendableStringBuilder<4096> Sb;
+			if (ReadFile(Path.string(), Sb) && Sb.Size() > 0)
+			{
+				HttpReq.WriteResponse(HttpResponseCode::OK, HttpContentType::kText, Sb.ToView());
+			}
+			else
+			{
+				HttpReq.WriteResponse(HttpResponseCode::NotFound);
+			}
+		},
+		HttpVerb::kGet);
+}
+
+void
+HttpHealthService::SetHealthInfo(HealthServiceInfo&& Info)
+{
+	m_HealthInfo = std::move(Info);
+}
+
+const char*
+HttpHealthService::BaseUri() const
+{
+	return "/health/";
+}
+
+void
+HttpHealthService::HandleRequest(HttpServerRequest& Request)
+{
+	if (!m_Router.HandleRequest(Request))
+	{
+		Request.WriteResponse(HttpResponseCode::OK, HttpContentType::kText, u8"OK!"sv);
+	}
+}
+
+}  // namespace zen
diff --git a/zenserver/diag/diagsvcs.h b/zenserver/diag/diagsvcs.h
index 61703e393..bd03f8023 100644
--- a/zenserver/diag/diagsvcs.h
+++ b/zenserver/diag/diagsvcs.h
@@ -5,6 +5,8 @@
 #include <zencore/iobuffer.h>
 #include <zenhttp/httpserver.h>
 
+#include <filesystem>
+
 //////////////////////////////////////////////////////////////////////////
 
 namespace zen {
@@ -82,26 +84,28 @@ private:
 	IoBuffer m_1k{m_1m, 0u, 1024};
 };
 
+struct HealthServiceInfo
+{
+	std::filesystem::path DataRoot;
+	std::filesystem::path AbsLogPath;
+	std::string			  HttpServerClass;
+	std::string			  BuildVersion;
+};
+
 class HttpHealthService : public HttpService
 {
 public:
-	HttpHealthService()	 = default;
+	HttpHealthService();
 	~HttpHealthService() = default;
 
-	virtual const char* BaseUri() const override { return "/health/"; }
+	void SetHealthInfo(HealthServiceInfo&& Info);
 
-	virtual void HandleRequest(HttpServerRequest& Request) override
-	{
-		using namespace std::literals;
-
-		switch (Request.RequestVerb())
-		{
-			case HttpVerb::kGet:
-				return Request.WriteResponse(HttpResponseCode::OK, HttpContentType::kText, u8"OK!"sv);
-		}
-	}
+	virtual const char* BaseUri() const override;
+	virtual void		HandleRequest(HttpServerRequest& Request) override final;
 
 private:
+	HttpRequestRouter m_Router;
+	HealthServiceInfo m_HealthInfo;
 };
 
 }  // namespace zen