Initial structure of log repo (#272)

* Initial look of log repo

* initial design of log repo, non-controversial

* Address reviews and remove unused import

* fix compliation errors

* Fix errors

* Address review changes

* nit fix

pkg/log/log.go

@@ -0,0 +1,68 @@
+package log
+
+import (
+	"context"
+
+	"github.com/sirupsen/logrus"
+)
+
+// Level describes the current log level.
+type Level uint32
+
+const (
+	// DebugLevel log level.
+	DebugLevel Level = Level(logrus.DebugLevel)
+	// InfoLevel log level.
+	InfoLevel Level = Level(logrus.InfoLevel)
+	// ErrorLevel log level.
+	ErrorLevel Level = Level(logrus.ErrorLevel)
+)
+
+type logger struct {
+	level Level
+	entry *logrus.Entry
+	ctx   context.Context
+	err   error
+}
+
+func Info() Logger {
+	return &logger{level: InfoLevel}
+}
+
+func Error() Logger {
+	return &logger{level: ErrorLevel}
+}
+
+func Debug() Logger {
+	return &logger{level: DebugLevel}
+}
+
+// Print adds `msg` to the log at `InfoLevel`. It is a wrapper for `Info().Print(msg)`, since this is the most common use case.
+func Print(msg string) {
+	Info().Print(msg)
+}
+
+func WithContext(ctx context.Context) {
+	Info().WithContext(ctx)
+}
+
+func (l *logger) Print(msg string) {
+	switch l.level {
+	case InfoLevel:
+		logrus.Info(msg)
+	case ErrorLevel:
+		logrus.Error(msg)
+	case DebugLevel:
+		logrus.Debug(msg)
+	}
+}
+
+func (l *logger) WithContext(ctx context.Context) Logger {
+	l.ctx = ctx
+	return l
+}
+
+func (l *logger) WithError(err error) Logger {
+	l.err = err
+	return l
+}

pkg/log/printer.go

@@ -0,0 +1,11 @@
+package log
+
+import (
+	"context"
+)
+
+type Logger interface {
+	Print(msg string)
+	WithContext(ctx context.Context) Logger
+	WithError(err error) Logger
+}