Remove logrus to allow for easier customization

internal/logger/logger.go

@@ -0,0 +1,129 @@
+/*
+© Copyright IBM Corporation 2018
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package logger
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"time"
+)
+
+// timestampFormat matches the format used by MQ messages (includes milliseconds)
+const timestampFormat string = "2006-01-02T15:04:05.000Z07:00"
+const debugLevel string = "DEBUG"
+const infoLevel string = "INFO"
+const errorLevel string = "ERROR"
+
+// A Logger is used to log messages to stdout
+type Logger struct {
+	writer      io.Writer
+	debug       bool
+	json        bool
+	processName string
+	pid         int
+}
+
+func NewLogger(writer io.Writer, debug bool, json bool) *Logger {
+	return &Logger{
+		writer:      writer,
+		debug:       debug,
+		json:        json,
+		processName: os.Args[0],
+		pid:         os.Getpid(),
+	}
+}
+
+func (l *Logger) format(entry map[string]interface{}) (string, error) {
+	if l.json {
+		b, err := json.Marshal(entry)
+		if err != nil {
+			return "", err
+		}
+		return string(b), err
+	}
+	return fmt.Sprintf("%v %v\n", entry["ibm_datetime"], entry["message"]), nil
+}
+
+// log logs a message at the specified level.  The message is enriched with
+// additional fields.
+func (l *Logger) log(level string, msg string) {
+	t := time.Now()
+	entry := map[string]interface{}{
+		"message":         fmt.Sprint(msg),
+		"ibm_datetime":    t.Format(timestampFormat),
+		"loglevel":        level,
+		"ibm_processName": l.processName,
+		"ibm_processId":   l.pid,
+	}
+	s, err := l.format(entry)
+	if err != nil {
+		// TODO: Fix this
+		fmt.Println(err)
+	}
+	if l.json {
+		fmt.Fprintln(l.writer, s)
+	} else {
+		fmt.Fprint(l.writer, s)
+	}
+}
+
+func (l *Logger) LogDirect(msg string) {
+	fmt.Println(msg)
+}
+
+func (l *Logger) Debug(args ...interface{}) {
+	if l.debug {
+		l.log(debugLevel, fmt.Sprint(args...))
+	}
+}
+
+func (l *Logger) Debugf(format string, args ...interface{}) {
+	if l.debug {
+		l.log(debugLevel, fmt.Sprintf(format, args...))
+	}
+}
+
+func (l *Logger) Print(args ...interface{}) {
+	l.log(infoLevel, fmt.Sprint(args...))
+}
+
+func (l *Logger) Println(args ...interface{}) {
+	l.Print(args...)
+}
+
+func (l *Logger) Printf(format string, args ...interface{}) {
+	l.log(infoLevel, fmt.Sprintf(format, args...))
+}
+
+func (l *Logger) PrintString(msg string) {
+	l.log(infoLevel, msg)
+}
+
+func (l *Logger) Error(args ...interface{}) {
+	l.log(errorLevel, fmt.Sprint(args...))
+}
+
+func (l *Logger) Errorf(format string, args ...interface{}) {
+	l.log(errorLevel, fmt.Sprintf(format, args...))
+}
+
+// TODO: Remove this
+func (l *Logger) Fatalf(format string, args ...interface{}) {
+	l.log("FATAL", fmt.Sprintf(format, args...))
+}