Split common utility functions into util package (#64)

util/decoder.go

@@ -0,0 +1,24 @@
+package util
+
+import (
+	"github.com/mitchellh/mapstructure"
+)
+
+// DecodeOther uses mapstructure to decode into target structure. Unused keys cause errors.
+func DecodeOther(log *Logger, other interface{}, cc interface{}) {
+	decoderConfig := &mapstructure.DecoderConfig{
+		Result:           cc,
+		ErrorUnused:      true,
+		WeaklyTypedInput: true,
+		DecodeHook:       mapstructure.StringToTimeDurationHookFunc(),
+	}
+
+	decoder, err := mapstructure.NewDecoder(decoderConfig)
+	if err != nil {
+		log.FATAL.Fatal(err)
+	}
+
+	if err := decoder.Decode(other); err != nil {
+		log.FATAL.Fatal(err)
+	}
+}