Allow logfile location to be changed with LOG_FILE env var fixes sysw…

…ard/sysward#38

logging/logging.go

@@ -18,6 +18,18 @@ func LogMsg(msg string) {
 		fmt.Println("Error writing to syslog: ", err)
 		return
 	}
+	defer logfile.Close()
+	if os.Getenv("LOG_FILE") != "" {
+		f, err := os.OpenFile(os.Getenv("LOG_FILE"), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
+		if err != nil {
+			fmt.Println("Error opening log file: ", err)
+			return
+		}
+		defer f.Close()
+		log.SetOutput(f)
+	} else {
+		log.SetOutput(logfile)
+	}
 	pc, _, _, _ := runtime.Caller(1)
 	caller := runtime.FuncForPC(pc).Name()
 	_, file, line, _ := runtime.Caller(0)
@@ -26,7 +38,8 @@ func LogMsg(msg string) {
 	pathLine := fmt.Sprintf("[%s:%d]", shortPath[1], line)
 	logString := fmt.Sprintf("%s{%s}:: %s", pathLine, caller, msg)
 	if os.Getenv("DEBUG") == "true" {
+		log.SetOutput(os.Stdout)
 		log.Info(logString)
 	}
-	logfile.Info(logString)
+	log.Info(logString)
 }