Implement support for using custom variables as macros.

Fixes #5364

doc/3.03-macros.md

@@ -106,6 +106,9 @@ hosts or services:
   HOSTADDRESS            | This is an alias for the `address` macro. If the `address` macro is not defined the host object's name is used instead.
   HOSTADDRESS6           | This is an alias for the `address6` macro. If the `address` macro is not defined the host object's name is used instead.
 
+Custom variables are made available as macros with the name "_HOST<name>"
+where <name> is the name of the custom variable.
+
 ### Service Macros
 
 The following service macros are available in all commands that are executed for
@@ -137,6 +140,9 @@ services:
   TOTALHOSTSERVICESUNKNOWN  | Number of services associated with the host which are in an `UNKNOWN` state.
   TOTALHOSTSERVICESCRITICAL | Number of services associated with the host which are in a `CRITICAL` state.
 
+Custom variables are made available as macros with the name "_SERVICE<name>"
+where <name> is the name of the custom variable.
+
 ### User Macros
 
 The following service macros are available in all commands that are executed for
@@ -149,6 +155,14 @@ users:
   USEREMAIL              | This is an alias for the `email` macro.
   USERPAGER              | This is an alias for the `pager` macro.
 
+Custom variables are made available as macros with the name "_USER<name>" and
+"_CONTACT<name>" where <name> is the name of the custom variable.
+
+### Notification Macros
+
+Custom variables are made available as macros with the name "_NOTIFICATION<name>"
+where <name> is the name of the custom variable.
+
 ### Global Macros
 
 The following macros are available in all commands:

lib/icinga/host.cpp

@@ -615,6 +615,12 @@ bool Host::ResolveMacro(const String& macro, const CheckResult::Ptr&, String *re
 		}
 	}
 
+	if (macro.SubStr(0, 5) == "_HOST") {
+		Dictionary::Ptr custom = GetCustom();
+		*result = custom ? custom->Get(macro.SubStr(5)) : "";
+		return true;
+	}
+
 	Dictionary::Ptr macros = GetMacros();
 
 	String name = macro;

lib/icinga/notification.cpp

@@ -325,6 +325,12 @@ void Notification::ExecuteNotificationHelper(NotificationType type, const User::
 
 bool Notification::ResolveMacro(const String& macro, const CheckResult::Ptr&, String *result) const
 {
+	if (macro.SubStr(0, 13) == "_NOTIFICATION") {
+		Dictionary::Ptr custom = GetCustom();
+		*result = custom ? custom->Get(macro.SubStr(13)) : "";
+		return true;
+	}
+
 	Dictionary::Ptr macros = GetMacros();
 
 	if (macros && macros->Contains(macro)) {

lib/icinga/service.cpp

@@ -474,6 +474,12 @@ bool Service::ResolveMacro(const String& macro, const CheckResult::Ptr& cr, Stri
 		}
 	}
 
+	if (macro.SubStr(0, 8) == "_SERVICE") {
+		Dictionary::Ptr custom = GetCustom();
+		*result = custom ? custom->Get(macro.SubStr(8)) : "";
+		return true;
+	}
+
 	Dictionary::Ptr macros = GetMacros();
 
 	if (macros && macros->Contains(macro)) {

lib/icinga/user.cpp

@@ -74,6 +74,14 @@ bool User::ResolveMacro(const String& macro, const CheckResult::Ptr&, String *re
 	} else if (macro == "USERDISPLAYNAME" || macro == "CONTACTALIAS") {
 		*result = GetDisplayName();
 		return true;
+	} else if (macro.SubStr(0, 5) == "_USER") {
+		Dictionary::Ptr custom = GetCustom();
+		*result = custom ? custom->Get(macro.SubStr(5)) : "";
+		return true;
+	} else if (macro.SubStr(0, 8) == "_CONTACT") {
+		Dictionary::Ptr custom = GetCustom();
+		*result = custom ? custom->Get(macro.SubStr(8)) : "";
+		return true;
 	} else {
 		String tmacro;