syslog: Allow to prepend a prefix to every log message

LogSyslog.st

@@ -17,6 +17,7 @@
 "
 
 LogTarget subclass: LogTargetSyslog [
+    | prefix |
     <comment: 'I can log everything to the syslog.'>
     <category: 'osmo-logging-syslog'>
 
@@ -77,13 +78,22 @@ LogTarget subclass: LogTargetSyslog [
         <category: 'output'>
         | level |
         level := self class logLevelMap at: aMessage level.
-        self class c_syslog: level fmt: '%s' args: {aMessage msg}.
+        self class c_syslog: level fmt: '%s%s' args: {self prefix. aMessage msg}.
     ]
 
     exception: aMessage [
-        self class c_syslog: aMessage level fmt: '%s' args: {'EXCEPTION occured'}.
+        self class c_syslog: aMessage level fmt: '%s%s'
+                    args: {self prefix. 'EXCEPTION occured'}.
         self print: aMessage.
     ]
+
+    prefix: aMsg [
+        prefix := aMsg.
+    ]
+
+    prefix [
+        ^ prefix ifNil: ['']
+    ]
 ]
 
 Eval [