Add simple debug logging.

internal/logger/config.go

@@ -0,0 +1,6 @@
+package logger
+
+// Config represents logging configuration.
+type Config struct {
+	Debug bool `yaml:"debug"`
+}

internal/logger/logger.go

@@ -0,0 +1,41 @@
+package logger
+
+import "log"
+
+// Logger responsible for all logging actions.
+type Logger struct {
+	config *Config
+}
+
+// NewLogger creates new logging wrapper and returns it to caller.
+func NewLogger(config *Config) *Logger {
+	l := &Logger{config: config}
+
+	return l
+}
+
+// Debugf is a wrapper around log.Printf which will work only when debug mode
+// is enabled.
+func (l *Logger) Debugf(template string, params ...interface{}) {
+	if l.config.Debug {
+		log.Printf(template, params...)
+	}
+}
+
+// Debugln is a wrapper around log.Println which will work only when debug mode
+// is enabled.
+func (l *Logger) Debugln(params ...interface{}) {
+	if l.config.Debug {
+		log.Println(params...)
+	}
+}
+
+// Infof is a wrapper around log.Printf.
+func (l *Logger) Infof(template string, params ...interface{}) {
+	log.Printf(template, params...)
+}
+
+// Infoln is a wrapper around log.Println.
+func (l *Logger) Infoln(params ...interface{}) {
+	log.Println(params...)
+}