Feature: TcpServer hot reload SSL file (#2150)

lib/inc/drogon/HttpAppFramework.h

@@ -806,6 +806,15 @@ class DROGON_EXPORT HttpAppFramework : public trantor::NonCopyable
         const std::vector<std::pair<std::string, std::string>>
             &sslConfCmds) = 0;
 
+    /// Reload the global cert file and private key file for https server
+    /// Note: The goal of this method is not to make the framework
+    /// use the new SSL path, but rather to reload the new content
+    /// from the old path while the framework is still running.
+    /// Typically, when our SSL is about to expire,
+    /// we need to reload the SSL. The purpose of this function
+    /// is to use the new SSL certificate without stopping the framework.
+    virtual HttpAppFramework &reloadSSLFiles() = 0;
+
     /// Add plugins
     /**
      * @param configs The plugins array

lib/src/HttpAppFrameworkImpl.cc

@@ -511,6 +511,12 @@ HttpAppFramework &HttpAppFrameworkImpl::setSSLFiles(const std::string &certPath,
     return *this;
 }
 
+HttpAppFramework &HttpAppFrameworkImpl::reloadSSLFiles()
+{
+    listenerManagerPtr_->reloadSSLFiles();
+    return *this;
+}
+
 void HttpAppFrameworkImpl::run()
 {
     if (!getLoop()->isInLoopThread())

lib/src/HttpAppFrameworkImpl.h

@@ -84,6 +84,9 @@ class HttpAppFrameworkImpl final : public HttpAppFramework
         override;
     HttpAppFramework &setSSLFiles(const std::string &certPath,
                                   const std::string &keyPath) override;
+
+    HttpAppFramework &reloadSSLFiles() override;
+
     void run() override;
     HttpAppFramework &registerWebSocketController(
         const std::string &pathName,

lib/src/HttpServer.h

@@ -49,6 +49,11 @@ class HttpServer : trantor::NonCopyable
         server_.enableSSL(std::move(policy));
     }
 
+    void reloadSSL()
+    {
+        server_.reloadSSL();
+    }
+
     const trantor::InetAddress &address() const
     {
         return server_.address();

lib/src/ListenerManager.cc

@@ -214,3 +214,11 @@ void ListenerManager::stopListening()
         listeningThread_->wait();
     }
 }
+
+void ListenerManager::reloadSSLFiles()
+{
+    for (auto &server : servers_)
+    {
+        server->reloadSSL();
+    }
+}

lib/src/ListenerManager.h

@@ -61,6 +61,8 @@ class ListenerManager : public trantor::NonCopyable
         afterAcceptSetSockOptCallback_ = std::move(cb);
     }
 
+    void reloadSSLFiles();
+
   private:
     struct ListenerInfo
     {

trantor

@@ -1 +1 @@
-Subproject commit 79e1ffc59aa1b9c8226c2988fe2e1185e97cd795
+Subproject commit 417c3520c4ff5dbceb44b0a5a87db86def7318b8