Ensure we don't leak file descriptors to child processes

fixes #8900

doc/17-language-reference.md

@@ -381,7 +381,6 @@ ObjectsPath         |**Read-write.** Contains the path of the Icinga 2 objects f
 PidPath             |**Read-write.** Contains the path of the Icinga 2 PID file. Defaults to RunDir + "/icinga2/icinga2.pid".
 Vars                |**Read-write.** Contains a dictionary with global custom attributes. Not set by default.
 NodeName            |**Read-write.** Contains the cluster node name. Set to the local hostname by default.
-UseVfork            |**Read-write.** Whether to use vfork(). Only available on *NIX. Defaults to true.
 EventEngine         |**Read-write.** The name of the socket event engine, can be "poll" or "epoll". The epoll interface is only supported on Linux.
 AttachDebugger      |**Read-write.** Whether to attach a debugger when Icinga 2 crashes. Defaults to false.
 RunAsUser           |**Read-write.** Defines the user the Icinga 2 daemon is running as. Used in the `init.conf` configuration file.

doc/20-development.md

@@ -118,9 +118,8 @@ the duplicate import in your `~/.gdbinit` file.
 
 Call GDB with the binary (`/usr/sbin/icinga2` is a wrapper script calling
 `/usr/lib64/icinga2/sbin/icinga2` since 2.4) and all arguments and run it in foreground.
-If VFork causes trouble, disable it inside the gdb run.
 
-    # gdb --args /usr/lib64/icinga2/sbin/icinga2 daemon -x debug -DUseVfork=0 --no-stack-rlimit
+    # gdb --args /usr/lib64/icinga2/sbin/icinga2 daemon -x debug --no-stack-rlimit
 
 The exact path to the Icinga 2 binary differs on each distribution. On Ubuntu
 it is installed into `/usr/lib/x86_64-linux-gnu/icinga2/sbin/icinga2` on 64-bit systems

icinga-app/icinga.cpp

@@ -31,6 +31,7 @@
 #include "base/scriptglobal.hpp"
 #include "base/context.hpp"
 #include "base/console.hpp"
+#include "base/process.hpp"
 #include "config.h"
 #include <boost/program_options.hpp>
 #include <boost/tuple/tuple.hpp>
@@ -153,13 +154,6 @@ int Main(void)
 	Application::DeclareRunAsGroup(ICINGA_GROUP);
 	Application::DeclareConcurrency(boost::thread::hardware_concurrency());
 
-	if (!ScriptGlobal::Exists("UseVfork"))
-#ifdef __APPLE__
-		ScriptGlobal::Set("UseVfork", false);
-#else /* __APPLE__ */
-		ScriptGlobal::Set("UseVfork", true);
-#endif /* __APPLE__ */
-
 	ScriptGlobal::Set("AttachDebugger", false);
 
 	ScriptGlobal::Set("PlatformKernel", Utility::GetPlatformKernel());
@@ -454,6 +448,8 @@ int Main(void)
 				}
 			}
 		}
+
+		Process::InitializeSpawnHelper();
 #endif /* _WIN32 */
 
 		std::vector<std::string> args;