Add log package

README.md

@@ -30,3 +30,17 @@ filecache.Load(&val, "path/to/cachefile", func() interface{} {
     return 100
 })
 ```
+
+### Log
+
+```go
+import "github.com/localhots/gobelt/log"
+```
+
+```go
+log.Info("New user signed up", log.F{
+    "name":  u.Name,
+    "email": u.Email,
+})
+log.Errorf("Invalid database flavor: %s", flavor)
+```

log/log.go

@@ -0,0 +1,72 @@
+package log
+
+import (
+	"github.com/lytics/logrus"
+)
+
+// Logger is a Logrus logger used by the package.
+var Logger *logrus.Logger
+
+// F is a short alias for a string to interface map.
+type F map[string]interface{}
+
+func init() {
+	Logger = logrus.New()
+}
+
+// Debug prints a debug message with given fields attached.
+func Debug(msg string, fields ...F) {
+	withFields(fields).Debug(msg)
+}
+
+// Debugf prints a formatted debug message.
+func Debugf(format string, args ...interface{}) {
+	logrus.Debugf(format, args...)
+}
+
+// Info prints an info message with given fields attached.
+func Info(msg string, fields ...F) {
+	withFields(fields).Info(msg)
+}
+
+// Infof prints a formatted info message.
+func Infof(format string, args ...interface{}) {
+	logrus.Infof(format, args...)
+}
+
+// Error prints an error message with given fields attached.
+func Error(msg string, fields ...F) {
+	withFields(fields).Error(msg)
+}
+
+// Errorf prints a formatted error message.
+func Errorf(format string, args ...interface{}) {
+	logrus.Errorf(format, args...)
+}
+
+// Fatal prints an error message with given fields attached and then exits.
+func Fatal(msg string, fields ...F) {
+	withFields(fields).Fatal(msg)
+}
+
+// Fatalf prints a formatted error message and then exits.
+func Fatalf(format string, args ...interface{}) {
+	logrus.Fatalf(format, args...)
+}
+
+func withFields(fields []F) *logrus.Entry {
+	switch len(fields) {
+	case 0:
+		return logrus.NewEntry(Logger)
+	case 1:
+		return logrus.WithFields(logrus.Fields(fields[0]))
+	default:
+		f := F{}
+		for i := 0; i < len(fields); i++ {
+			for k, v := range fields[i] {
+				f[k] = v
+			}
+		}
+		return logrus.WithFields(logrus.Fields(f))
+	}
+}