Merge pull request #374 from ClusterCockpit/review_logging

Review logging

pkg/log/log.go

@@ -46,12 +46,12 @@ var loglevel string = "info"
 /* CONFIG */
 
 func Init(lvl string, logdate bool) {
-
+	// Discard I/O for all writers below selected loglevel; <CRITICAL> is always written.
 	switch lvl {
 	case "crit":
 		ErrWriter = io.Discard
 		fallthrough
-	case "err", "fatal":
+	case "err":
 		WarnWriter = io.Discard
 		fallthrough
 	case "warn":
@@ -63,8 +63,7 @@ func Init(lvl string, logdate bool) {
 		// Nothing to do...
 		break
 	default:
-		fmt.Printf("pkg/log: Flag 'loglevel' has invalid value %#v\npkg/log: Will use default loglevel 'debug'\n", lvl)
-		//SetLogLevel("debug")
+		fmt.Printf("pkg/log: Flag 'loglevel' has invalid value %#v\npkg/log: Will use default loglevel '%s'\n", lvl, loglevel)
 	}
 
 	if !logdate {
@@ -84,109 +83,138 @@ func Init(lvl string, logdate bool) {
 	loglevel = lvl
 }
 
-/* PRINT */
-
-// Private helper
-func printStr(v ...interface{}) string {
-	return fmt.Sprint(v...)
-}
-
-// Uses Info() -> If errorpath required at some point:
-// Will need own writer with 'Output(2, out)' to correctly render path
-func Print(v ...interface{}) {
-	Info(v...)
-}
-
-func Debug(v ...interface{}) {
-	DebugLog.Output(2, printStr(v...))
-}
-
-func Info(v ...interface{}) {
-	InfoLog.Output(2, printStr(v...))
-}
-
-func Warn(v ...interface{}) {
-	WarnLog.Output(2, printStr(v...))
-}
-
-func Error(v ...interface{}) {
-	ErrLog.Output(2, printStr(v...))
-}
-
-// Writes panic stacktrace, but keeps application alive
-func Panic(v ...interface{}) {
-	ErrLog.Output(2, printStr(v...))
-	panic("Panic triggered ...")
-}
-
-func Crit(v ...interface{}) {
-	CritLog.Output(2, printStr(v...))
-}
-
-// Writes critical log, stops application
-func Fatal(v ...interface{}) {
-	CritLog.Output(2, printStr(v...))
-	os.Exit(1)
-}
-
-/* PRINT FORMAT*/
-
-// Private helper
-func printfStr(format string, v ...interface{}) string {
-	return fmt.Sprintf(format, v...)
-}
-
-// Uses Infof() -> If errorpath required at some point:
-// Will need own writer with 'Output(2, out)' to correctly render path
-func Printf(format string, v ...interface{}) {
-	Infof(format, v...)
-}
-
-func Debugf(format string, v ...interface{}) {
-	DebugLog.Output(2, printfStr(format, v...))
-}
-
-func Infof(format string, v ...interface{}) {
-	InfoLog.Output(2, printfStr(format, v...))
-}
-
-func Warnf(format string, v ...interface{}) {
-	WarnLog.Output(2, printfStr(format, v...))
-}
-
-func Errorf(format string, v ...interface{}) {
-	ErrLog.Output(2, printfStr(format, v...))
-}
-
-// Writes panic stacktrace, but keeps application alive
-func Panicf(format string, v ...interface{}) {
-	ErrLog.Output(2, printfStr(format, v...))
-	panic("Panic triggered ...")
-}
-
-func Critf(format string, v ...interface{}) {
-	CritLog.Output(2, printfStr(format, v...))
-}
-
-// Writes crit log, stops application
-func Fatalf(format string, v ...interface{}) {
-	CritLog.Output(2, printfStr(format, v...))
-	os.Exit(1)
-}
+/* HELPER */
 
 func Loglevel() string {
 	return loglevel
 }
 
-/* SPECIAL */
+/* PRIVATE HELPER */
 
-// func Finfof(w io.Writer, format string, v ...interface{}) {
-// 	if w != io.Discard {
-// 		if logDateTime {
-// 			currentTime := time.Now()
-// 			fmt.Fprintf(InfoWriter, currentTime.String()+InfoPrefix+format+"\n", v...)
-// 		} else {
-// 			fmt.Fprintf(InfoWriter, InfoPrefix+format+"\n", v...)
-// 		}
-// 	}
-// }
+// Return unformatted string
+func printStr(v ...interface{}) string {
+	return fmt.Sprint(v...)
+}
+
+// Return formatted string
+func printfStr(format string, v ...interface{}) string {
+	return fmt.Sprintf(format, v...)
+}
+
+/* PRINT */
+
+// Prints to STDOUT without string formatting; application continues.
+// Used for special cases not requiring log information like date or location.
+func Print(v ...interface{}) {
+	fmt.Fprintln(os.Stdout, v...)
+}
+
+// Prints to STDOUT without string formatting; application exits with error code 0.
+// Used for exiting succesfully with message after expected outcome, e.g. successful single-call application runs.
+func Exit(v ...interface{}) {
+	fmt.Fprintln(os.Stdout, v...)
+	os.Exit(0)
+}
+
+// Prints to STDOUT without string formatting; application exits with error code 1.
+// Used for terminating with message after to be expected errors, e.g. wrong arguments or during init().
+func Abort(v ...interface{}) {
+	fmt.Fprintln(os.Stdout, v...)
+	os.Exit(1)
+}
+
+// Prints to DEBUG writer without string formatting; application continues.
+// Used for logging additional information, primarily for development.
+func Debug(v ...interface{}) {
+	DebugLog.Output(2, printStr(v...))
+}
+
+// Prints to INFO writer without string formatting; application continues.
+// Used for logging additional information, e.g. notable returns or common fail-cases.
+func Info(v ...interface{}) {
+	InfoLog.Output(2, printStr(v...))
+}
+
+// Prints to WARNING writer without string formatting; application continues.
+// Used for logging important information, e.g. uncommon edge-cases or administration related information.
+func Warn(v ...interface{}) {
+	WarnLog.Output(2, printStr(v...))
+}
+
+// Prints to ERROR writer without string formatting; application continues.
+// Used for logging errors, but code still can return default(s) or nil.
+func Error(v ...interface{}) {
+	ErrLog.Output(2, printStr(v...))
+}
+
+// Prints to CRITICAL writer without string formatting; application exits with error code 1.
+// Used for terminating on unexpected errors with date and code location.
+func Fatal(v ...interface{}) {
+	CritLog.Output(2, printStr(v...))
+	os.Exit(1)
+}
+
+// Prints to PANIC function without string formatting; application exits with panic.
+// Used for terminating on unexpected errors with stacktrace.
+func Panic(v ...interface{}) {
+	panic(printStr(v...))
+}
+
+/* PRINT FORMAT*/
+
+// Prints to STDOUT with string formatting; application continues.
+// Used for special cases not requiring log information like date or location.
+func Printf(format string, v ...interface{}) {
+	fmt.Fprintf(os.Stdout, format, v...)
+}
+
+// Prints to STDOUT with string formatting; application exits with error code 0.
+// Used for exiting succesfully with message after expected outcome, e.g. successful single-call application runs.
+func Exitf(format string, v ...interface{}) {
+	fmt.Fprintf(os.Stdout, format, v...)
+	os.Exit(0)
+}
+
+// Prints to STDOUT with string formatting; application exits with error code 1.
+// Used for terminating with message after to be expected errors, e.g. wrong arguments or during init().
+func Abortf(format string, v ...interface{}) {
+	fmt.Fprintf(os.Stdout, format, v...)
+	os.Exit(1)
+}
+
+// Prints to DEBUG writer with string formatting; application continues.
+// Used for logging additional information, primarily for development.
+func Debugf(format string, v ...interface{}) {
+	DebugLog.Output(2, printfStr(format, v...))
+}
+
+// Prints to INFO writer with string formatting; application continues.
+// Used for logging additional information, e.g. notable returns or common fail-cases.
+func Infof(format string, v ...interface{}) {
+	InfoLog.Output(2, printfStr(format, v...))
+}
+
+// Prints to WARNING writer with string formatting; application continues.
+// Used for logging important information, e.g. uncommon edge-cases or administration related information.
+func Warnf(format string, v ...interface{}) {
+	WarnLog.Output(2, printfStr(format, v...))
+}
+
+// Prints to ERROR writer with string formatting; application continues.
+// Used for logging errors, but code still can return default(s) or nil.
+func Errorf(format string, v ...interface{}) {
+	ErrLog.Output(2, printfStr(format, v...))
+}
+
+// Prints to CRITICAL writer with string formatting; application exits with error code 1.
+// Used for terminating on unexpected errors with date and code location.
+func Fatalf(format string, v ...interface{}) {
+	CritLog.Output(2, printfStr(format, v...))
+	os.Exit(1)
+}
+
+// Prints to PANIC function with string formatting; application exits with panic.
+// Used for terminating on unexpected errors with stacktrace.
+func Panicf(format string, v ...interface{}) {
+	panic(printfStr(format, v...))
+}