feature(signal): Add option to disable signal handling (#742)

config.example.json

@@ -172,6 +172,8 @@
         },
         //run_as_daemon: False by default
         "run_as_daemon": false,
+        //handle_sig_term: True by default
+        "handle_sig_term": true,
         //relaunch_on_error: False by default, if true, the program will be restart by the parent after exiting;
         "relaunch_on_error": false,
         //use_sendfile: True by default, if true, the program 

drogon_ctl/templates/config.csp

@@ -172,6 +172,8 @@
         },
         //run_as_daemon: False by default
         "run_as_daemon": false,
+        //handle_sig_term: True by default
+        "handle_sig_term": true,
         //relaunch_on_error: False by default, if true, the program will be restart by the parent after exiting;
         "relaunch_on_error": false,
         //use_sendfile: True by default, if true, the program 

examples/simple_reverse_proxy/config.json

@@ -87,6 +87,8 @@
         },
         //run_as_daemon: False by default
         "run_as_daemon": false,
+        //handle_sig_term: True by default
+        "handle_sig_term": true,
         //relaunch_on_error: False by default, if true, the program will be restart by the parent after exiting;
         "relaunch_on_error": false,
         //use_sendfile: True by default, if true, the program 

lib/inc/drogon/HttpAppFramework.h

@@ -816,6 +816,16 @@ class HttpAppFramework : public trantor::NonCopyable
      */
     virtual HttpAppFramework &enableRunAsDaemon() = 0;
 
+    /// Disable the handling of SIGTERM signal.
+    /**
+     * Enabled by default.
+     *
+     * @note
+     * This operation can be performed by an option in the configuration file.
+     * When disabled setTermSignalHandler() is useless
+     */
+    virtual HttpAppFramework &disableSigtermHandling() = 0;
+
     /// Make the application restart after crashing.
     /**
      * Disabled by default.

lib/src/ConfigLoader.cc

@@ -393,6 +393,12 @@ static void loadApp(const Json::Value &app)
     {
         drogon::app().enableRunAsDaemon();
     }
+    // handle SIGTERM
+    auto handleSigterm = app.get("handle_sig_term", true).asBool();
+    if (!handleSigterm)
+    {
+        drogon::app().disableSigtermHandling();
+    }
     // relaunch
     auto relaunch = app.get("relaunch_on_error", false).asBool();
     if (relaunch)

lib/src/HttpAppFrameworkImpl.cc

@@ -463,7 +463,10 @@ void HttpAppFrameworkImpl::run()
         getLoop()->resetAfterFork();
 #endif
     }
-    signal(SIGTERM, TERMFunction);
+    if (handleSigterm_)
+    {
+        signal(SIGTERM, TERMFunction);
+    }
     // set logger
     if (!logPath_.empty())
     {

lib/src/HttpAppFrameworkImpl.h

@@ -256,6 +256,11 @@ class HttpAppFrameworkImpl : public HttpAppFramework
         runAsDaemon_ = true;
         return *this;
     }
+    virtual HttpAppFramework &disableSigtermHandling() override
+    {
+        handleSigterm_ = false;
+        return *this;
+    }
     virtual HttpAppFramework &enableRelaunchOnError() override
     {
         relaunchOnError_ = true;
@@ -583,6 +588,7 @@ class HttpAppFrameworkImpl : public HttpAppFramework
     std::atomic<int64_t> connectionNum_{0};
 
     bool runAsDaemon_{false};
+    bool handleSigterm_{true};
     bool relaunchOnError_{false};
     std::string logPath_{""};
     std::string logfileBaseName_{""};