Dynamic Configuration Refactoring

log/log.go

@@ -0,0 +1,145 @@
+package log
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/sirupsen/logrus"
+)
+
+type contextKey int
+
+const (
+	loggerKey contextKey = iota
+)
+
+// Logger the Traefik logger
+type Logger interface {
+	logrus.FieldLogger
+	WriterLevel(logrus.Level) *io.PipeWriter
+}
+
+var (
+	mainLogger  Logger
+	logFilePath string
+	logFile     *os.File
+)
+
+func init() {
+	mainLogger = logrus.StandardLogger()
+	logrus.SetOutput(os.Stdout)
+}
+
+// SetLogger sets the logger.
+func SetLogger(l Logger) {
+	mainLogger = l
+}
+
+// SetOutput sets the standard logger output.
+func SetOutput(out io.Writer) {
+	logrus.SetOutput(out)
+}
+
+// SetFormatter sets the standard logger formatter.
+func SetFormatter(formatter logrus.Formatter) {
+	logrus.SetFormatter(formatter)
+}
+
+// SetLevel sets the standard logger level.
+func SetLevel(level logrus.Level) {
+	logrus.SetLevel(level)
+}
+
+// GetLevel returns the standard logger level.
+func GetLevel() logrus.Level {
+	return logrus.GetLevel()
+}
+
+// Str adds a string field
+func Str(key, value string) func(logrus.Fields) {
+	return func(fields logrus.Fields) {
+		fields[key] = value
+	}
+}
+
+// With Adds fields
+func With(ctx context.Context, opts ...func(logrus.Fields)) context.Context {
+	logger := FromContext(ctx)
+
+	fields := make(logrus.Fields)
+	for _, opt := range opts {
+		opt(fields)
+	}
+	logger = logger.WithFields(fields)
+
+	return context.WithValue(ctx, loggerKey, logger)
+}
+
+// FromContext Gets the logger from context
+func FromContext(ctx context.Context) Logger {
+	if ctx == nil {
+		panic("nil context")
+	}
+
+	logger, ok := ctx.Value(loggerKey).(Logger)
+	if !ok {
+		logger = mainLogger
+	}
+
+	return logger
+}
+
+// WithoutContext Gets the main logger
+func WithoutContext() Logger {
+	return mainLogger
+}
+
+// OpenFile opens the log file using the specified path
+func OpenFile(path string) error {
+	logFilePath = path
+
+	var err error
+	logFile, err = os.OpenFile(logFilePath, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
+	if err != nil {
+		return err
+	}
+
+	SetOutput(logFile)
+	return nil
+}
+
+// CloseFile closes the log and sets the Output to stdout
+func CloseFile() error {
+	logrus.SetOutput(os.Stdout)
+
+	if logFile != nil {
+		return logFile.Close()
+	}
+	return nil
+}
+
+// RotateFile closes and reopens the log file to allow for rotation
+// by an external source.  If the log isn't backed by a file then
+// it does nothing.
+func RotateFile() error {
+	logger := FromContext(context.Background())
+
+	if logFile == nil && logFilePath == "" {
+		logger.Debug("Traefik log is not writing to a file, ignoring rotate request")
+		return nil
+	}
+
+	if logFile != nil {
+		defer func(f *os.File) {
+			_ = f.Close()
+		}(logFile)
+	}
+
+	if err := OpenFile(logFilePath); err != nil {
+		return fmt.Errorf("error opening log file: %s", err)
+	}
+
+	return nil
+}