Add FileLogger option

v2/pkg/logger/filelogger.go

@@ -0,0 +1,66 @@
+package logger
+
+import (
+	"log"
+	"os"
+)
+
+// FileLogger is a utility to log messages to a number of destinations
+type FileLogger struct {
+	filename string
+}
+
+// NewFileLogger creates a new Logger.
+func NewFileLogger(filename string) Logger {
+	return &FileLogger{
+		filename: filename,
+	}
+}
+
+// Print works like Sprintf.
+func (l *FileLogger) Print(message string) {
+	f, err := os.OpenFile(l.filename, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if _, err := f.WriteString(message); err != nil {
+		f.Close()
+		log.Fatal(err)
+	}
+	f.Close()
+}
+
+func (l *FileLogger) Println(message string) {
+	l.Print(message + "\n")
+}
+
+// Trace level logging. Works like Sprintf.
+func (l *FileLogger) Trace(message string) {
+	l.Println("TRACE | " + message)
+}
+
+// Debug level logging. Works like Sprintf.
+func (l *FileLogger) Debug(message string) {
+	l.Println("DEBUG | " + message)
+}
+
+// Info level logging. Works like Sprintf.
+func (l *FileLogger) Info(message string) {
+	l.Println("INFO  | " + message)
+}
+
+// Warning level logging. Works like Sprintf.
+func (l *FileLogger) Warning(message string) {
+	l.Println("WARN  | " + message)
+}
+
+// Error level logging. Works like Sprintf.
+func (l *FileLogger) Error(message string) {
+	l.Println("ERROR | " + message)
+}
+
+// Fatal level logging. Works like Sprintf.
+func (l *FileLogger) Fatal(message string) {
+	l.Println("FATAL | " + message)
+	os.Exit(1)
+}