rewrite logger

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

logger/micro.go

@@ -0,0 +1,154 @@
+package logger
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"runtime"
+	"strings"
+	"sync"
+	"time"
+)
+
+func init() {
+	lvl, err := GetLevel(os.Getenv("MICRO_LOG_LEVEL"))
+	if err != nil {
+		lvl = InfoLevel
+	}
+
+	DefaultLogger = NewLogger(WithLevel(lvl))
+}
+
+type defaultLogger struct {
+	sync.RWMutex
+	opts Options
+	enc  *json.Encoder
+}
+
+// Init(opts...) should only overwrite provided options
+func (l *defaultLogger) Init(opts ...Option) error {
+	l.Lock()
+	defer l.Unlock()
+
+	for _, o := range opts {
+		o(&l.opts)
+	}
+	l.enc = json.NewEncoder(l.opts.Out)
+	return nil
+}
+
+func (l *defaultLogger) String() string {
+	return "micro"
+}
+
+func (l *defaultLogger) V(level Level) bool {
+	return l.opts.Level.Enabled(level)
+}
+
+func (l *defaultLogger) Fields(fields map[string]interface{}) Logger {
+	l.Lock()
+	l.opts.Fields = copyFields(fields)
+	l.Unlock()
+	return l
+}
+
+func copyFields(src map[string]interface{}) map[string]interface{} {
+	dst := make(map[string]interface{}, len(src))
+	for k, v := range src {
+		dst[k] = v
+	}
+	return dst
+}
+
+// logCallerfilePath returns a package/file:line description of the caller,
+// preserving only the leaf directory name and file name.
+func logCallerfilePath(loggingFilePath string) string {
+	// To make sure we trim the path correctly on Windows too, we
+	// counter-intuitively need to use '/' and *not* os.PathSeparator here,
+	// because the path given originates from Go stdlib, specifically
+	// runtime.Caller() which (as of Mar/17) returns forward slashes even on
+	// Windows.
+	//
+	// See https://github.com/golang/go/issues/3335
+	// and https://github.com/golang/go/issues/18151
+	//
+	// for discussion on the issue on Go side.
+	idx := strings.LastIndexByte(loggingFilePath, '/')
+	if idx == -1 {
+		return loggingFilePath
+	}
+	idx = strings.LastIndexByte(loggingFilePath[:idx], '/')
+	if idx == -1 {
+		return loggingFilePath
+	}
+	return loggingFilePath[idx+1:]
+}
+
+func (l *defaultLogger) Info(msg string, args ...interface{}) {
+	l.log(InfoLevel, msg, args...)
+}
+
+func (l *defaultLogger) Error(msg string, args ...interface{}) {
+	l.log(ErrorLevel, msg, args...)
+}
+
+func (l *defaultLogger) Debug(msg string, args ...interface{}) {
+	l.log(DebugLevel, msg, args...)
+}
+
+func (l *defaultLogger) Warn(msg string, args ...interface{}) {
+	l.log(WarnLevel, msg, args...)
+}
+
+func (l *defaultLogger) Trace(msg string, args ...interface{}) {
+	l.log(TraceLevel, msg, args...)
+}
+
+func (l *defaultLogger) Fatal(msg string, args ...interface{}) {
+	l.log(FatalLevel, msg, args...)
+	os.Exit(1)
+}
+
+func (l *defaultLogger) log(level Level, msg string, args ...interface{}) {
+	if !l.V(level) {
+		return
+	}
+
+	l.RLock()
+	fields := copyFields(l.opts.Fields)
+	l.RUnlock()
+
+	fields["level"] = level.String()
+
+	if _, file, line, ok := runtime.Caller(l.opts.CallerSkipCount); ok {
+		fields["caller"] = fmt.Sprintf("%s:%d", logCallerfilePath(file), line)
+	}
+
+	fields["timestamp"] = time.Now().Format("2006-01-02 15:04:05")
+	if len(msg) > 0 {
+		if len(args) > 0 {
+			fields["msg"] = fmt.Sprintf(msg, args...)
+		} else {
+			fields["msg"] = msg
+		}
+	}
+	l.RLock()
+	_ = l.enc.Encode(fields)
+	l.RUnlock()
+}
+
+func (l *defaultLogger) Options() Options {
+	// not guard against options Context values
+	l.RLock()
+	opts := l.opts
+	opts.Fields = copyFields(l.opts.Fields)
+	l.RUnlock()
+	return opts
+}
+
+// NewLogger builds a new logger based on options
+func NewLogger(opts ...Option) Logger {
+	l := &defaultLogger{opts: NewOptions(opts...)}
+	l.enc = json.NewEncoder(l.opts.Out)
+	return l
+}