The service is not restarted if there is an error in the configuration (

#16)

* The service is not restarted if there is an error in the configuration
* Added TConfigException to config parser

.gitignore

@@ -21,3 +21,6 @@ wb-mqtt-mbgate
 
 # Visual Studio Code
 .vscode
+
+# CLion
+.idea

Makefile

@@ -10,7 +10,7 @@ ifeq ($(origin CXX),default)
 endif
 
 TARGET = wb-mqtt-mbgate
-OBJS = main.o config_parser.o
+OBJS = main.o config_parser.o mbgate_exception.o
 SRC_DIR = src
 
 COMMON_OBJS = i_modbus_server_observer.o i_modbus_backend.o modbus_wrapper.o mqtt_converters.o observer.o modbus_lmb_backend.o log.o

debian/changelog

@@ -1,3 +1,9 @@
+wb-mqtt-mbgate (1.4.0) stable; urgency=medium
+
+  * The service is not restarted if there is an error in the configuration
+
+ -- Roman Kochkin <[email protected]>  Thu, 06 Oct 2022 16:08:23 +0400
+
 wb-mqtt-mbgate (1.3.1) stable; urgency=medium
 
   * Fix default port setting in bullseye for UNIX socket connection

debian/wb-mqtt-mbgate.service

@@ -11,5 +11,8 @@ User=root
 ExecStart=/usr/bin/wb-mqtt-mbgate -c /etc/wb-mqtt-mbgate.conf
 ExecStartPre=/usr/bin/wb-mqtt-mbgate-confgen -c /etc/wb-mqtt-mbgate.conf
 
+# Service not restarting after return EXIT_NOTCONFIGURED
+RestartPreventExitStatus=6
+
 [Install]
 WantedBy=multi-user.target

src/config_parser.cpp

@@ -15,6 +15,7 @@
 #include "mqtt_converters.h"
 #include "modbus_lmb_backend.h"
 #include "observer.h"
+#include "mbgate_exception.h"
 
 using namespace std;
 using namespace WBMQTT;
@@ -37,8 +38,12 @@ IConfigParser::~IConfigParser()
 TJSONConfigParser::TJSONConfigParser(const string& config_file, const string& schema_file) :
     Root(Parse(config_file))
 {
-    auto schema(Parse(schema_file));
-    Validate(Root, schema);
+    try {
+        auto schema(Parse(schema_file));
+        Validate(Root, schema);
+    } catch (const std::runtime_error& e){
+        throw TConfigException(e.what());
+    }
 }
 
 bool TJSONConfigParser::Debug()
@@ -80,7 +85,7 @@ tuple<PModbusServer, PMqttClient> TJSONConfigParser::Build()
 
             modbusBackend = make_shared<TModbusRTUBackend>(args);
         } else {
-            throw runtime_error("invalid modbus type: '" + type + "'");
+            throw TConfigException("invalid modbus type: '" + type + "'");
         }
     }
 
@@ -154,7 +159,7 @@ void TJSONConfigParser::_BuildStore(TStoreType type, const Json::Value& list, PM
                 } else if (format == "bcd") {
                     int_type = TMQTTIntConverter::BCD;
                 } else {
-                    throw runtime_error("Unknown integer format: " + format);
+                    throw TConfigException("Unknown integer format: " + format);
                 }
 
                 conv = make_shared<TMQTTIntConverter>(int_type, scale, size, byteswap, wordswap);
@@ -169,7 +174,7 @@ void TJSONConfigParser::_BuildStore(TStoreType type, const Json::Value& list, PM
         try {
             modbus->Observe(obs, type, TModbusAddressRange(address, size), slave_id);
         } catch (const WrongSegmentException &e) {
-            throw runtime_error(string("Address overlapping: ") + StoreTypeToString(type) + ": topic " + topic);
+            throw TConfigException(string("Address overlapping: ") + StoreTypeToString(type) + ": topic " + topic);
         }
     }
 }

src/main.cpp

@@ -8,6 +8,7 @@
 #include "modbus_lmb_backend.h"
 #include "observer.h"
 #include "config_parser.h"
+#include "mbgate_exception.h"
 
 #include <wblib/signal_handling.h>
 
@@ -30,8 +31,9 @@ using namespace WBMQTT;
 
 const auto DRIVER_STOP_TIMEOUT_S = chrono::seconds(10);
 
-namespace
-{
+namespace {
+    constexpr auto EXIT_NOTCONFIGURED = 6;   // The program is not configured
+
     void PrintUsage()
     {
         cout << WBMQTT_NAME << XSTR(WBMQTT_VERSION) 
@@ -175,10 +177,13 @@ int main(int argc, char *argv[])
 
         t->Stop();
         WBMQTT::SignalHandling::Wait();
-    } catch (const exception& e) {
+    } catch (const TConfigException &e) {
+        LOG(Error) << "FATAL: " << e.what();
+        return EXIT_NOTCONFIGURED;
+    } catch (const exception &e) {
         LOG(Error) << "FATAL: " << e.what();
-        return 1;
+        return EXIT_FAILURE;
     }
 
-    return 0;
+    return EXIT_SUCCESS;
 }

src/mbgate_exception.cpp

@@ -0,0 +1,4 @@
+#include "mbgate_exception.h"
+
+TConfigException::TConfigException(const std::string &message)
+        : std::runtime_error("Configuration error: " + message) {}

src/mbgate_exception.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include <stdexcept>
+#include <string>
+
+class TConfigException : public std::runtime_error {
+public:
+    explicit TConfigException(const std::string &message);
+};