Automatic IOC systemd startup from Power_switch

CMakeLists.txt

@@ -64,6 +64,7 @@ set_property(
 target_link_libraries(
   power_switch
   PRIVATE
+    /usr/lib64/libsystemd.so
     midas::mfe
     m_epics_ca
     ${LIBS}

README.md

@@ -40,6 +40,10 @@ Start it with specified frontend name and equipment name
 ```bash
 $ $PWD/build/ePowerSwitchFront <frontendName> <equipmentName>
 ```
+Start it with also a systemd service
+```bash
+$ $PWD/build/ePowerSwitchFront <frontendName> <equipmentName> <serviceName>
+```
 
 # Features
 

src/device/power_switch.cpp

@@ -2,9 +2,8 @@
 #include "odbxx.h"
 #include "power_switch_config.h"
 #include "tmfe.h"
-#include <string>
-
 #include <sstream>
+#include <string>
 
 /**
  * @brief Insert a integer value between two string

src/frontend/power_switch_scfe.cpp

@@ -2,6 +2,7 @@
 #include "../device/power_switch.h"
 #include "power_switch_scfe_config.h"
 #include "tmfe.h"
+#include <systemd/sd-bus.h>
 
 int main(int argc, char *argv[]) {
 
@@ -13,8 +14,10 @@ int main(int argc, char *argv[]) {
 
     std::string frontendName;
     std::string equipmentName;
+    std::string serviceName;
 
-    if (argc == 1) {
+    switch (argc) {
+    case 1:
         frontendName = DEFAULT_FRONTEND_NAME;
         TMFE::Instance()->Msg(MINFO, __FUNCTION__,
                               "No frontend name provided; %s will be used",
@@ -23,22 +26,37 @@ int main(int argc, char *argv[]) {
         TMFE::Instance()->Msg(MINFO, __FUNCTION__,
                               "No equipment name provided; %s will be used",
                               DEFAULT_EQUIPMENT_NAME);
-    }
-    if (argc == 2) {
+        break;
+    case 2:
         frontendName = std::string(argv[1]);
         argv++;
         argc--;
         TMFE::Instance()->Msg(MINFO, __FUNCTION__,
                               "No equipment name provided; %s will be use",
                               DEFAULT_EQUIPMENT_NAME);
-    } else if (argc == 3) {
+        break;
+    case 3:
         frontendName = std::string(argv[1]);
         equipmentName = std::string(argv[2]);
         argv += 2;
         argc -= 2;
+        break;
+
+    case 4:
+        frontendName = std::string(argv[1]);
+        equipmentName = std::string(argv[2]);
+        serviceName = std::string(argv[3]);
+        argv += 3;
+        argc -= 3;
+    default:
+        break;
     }
 
-    auto front = powerSwitchSCFE(frontendName, equipmentName);
+    auto front =
+        (serviceName.empty())
+            ? powerSwitchSCFE(frontendName, equipmentName)
+            : powerSwitchSCFE(frontendName, equipmentName, serviceName);
+
     front.FeMain(argc, argv);
 }
 
@@ -46,4 +64,44 @@ powerSwitchSCFE::powerSwitchSCFE(std::string frontendName,
                                  std::string equipmentName) {
     FeSetName(frontendName.c_str());
     FeAddEquipment(new powerSwitch(equipmentName.c_str(), __FILE__));
-}
+}
+
+powerSwitchSCFE::powerSwitchSCFE(std::string frontendName,
+                                 std::string equipmentName,
+                                 std::string serviceName) {
+    verifySystemdService(serviceName);
+    FeSetName(frontendName.c_str());
+    FeAddEquipment(new powerSwitch(equipmentName.c_str(), __FILE__));
+}
+
+void powerSwitchSCFE::verifySystemdService(std::string serviceName) {
+    sd_bus *bus = nullptr;
+    sd_bus_error error = SD_BUS_ERROR_NULL;
+    sd_bus_message *reply = nullptr;
+
+    int returnCode = sd_bus_open_system(&bus);
+    if (returnCode < 0) {
+        TMFE::Instance()->Msg(
+            MINFO, __FUNCTION__,
+            "Systemd d-bus cannot be opened, error code %d - Starting "
+            "without verifying service current status\n",
+            returnCode);
+    }
+
+    returnCode = sd_bus_call_method(
+        bus, SystemdPathConfig::DBUS_SYSTEMD_DESTINATION.c_str(),
+        SystemdPathConfig::DBUS_SYSTEMD_PATH.c_str(),
+        SystemdPathConfig::DBUS_SYSTEMD_INTERFACE_MANAGER.c_str(), "StartUnit",
+        &error, &reply, "ss", serviceName.c_str(), "replace");
+    if (returnCode < 0) {
+        TMFE::Instance()->Msg(
+            MERROR, __FUNCTION__,
+            "Couldn't start %s service, error code %d - Aborting\n",
+            serviceName.c_str(), returnCode);
+        exit(-1);
+    }
+
+    sd_bus_error_free(&error);
+    sd_bus_message_unref(reply);
+    sd_bus_flush_close_unref(bus);
+}

src/frontend/power_switch_scfe.h

@@ -12,6 +12,13 @@ class powerSwitchSCFE : public TMFrontend {
      * @param equipmentName name shown on Midas for the equipment
      */
     powerSwitchSCFE(std::string frontendName, std::string equipmentName);
+    powerSwitchSCFE(std::string frontendName, std::string equipmentName,
+                    std::string serviceName);
+
+  private:
+    /*
+     */
+    void verifySystemdService(std::string serviceName);
 };
 
 #endif

src/frontend/power_switch_scfe_config.h

@@ -3,5 +3,14 @@
 
 #define DEFAULT_FRONTEND_NAME "powerSwitch"
 #define DEFAULT_EQUIPMENT_NAME "powerSwitch"
+#include <string>
+
+namespace SystemdPathConfig {
+
+const std::string DBUS_SYSTEMD_DESTINATION = "org.freedesktop.systemd1";
+const std::string DBUS_SYSTEMD_PATH = "/org/freedesktop/systemd1";
+const std::string DBUS_SYSTEMD_INTERFACE_MANAGER =
+    "org.freedesktop.systemd1.Manager";
+}; // namespace SystemdPathConfig
 
 #endif