feat: documentation and cleanup command

hcloudimages/internal/labelutil/labels.go

@@ -0,0 +1,30 @@
+package labelutil
+
+import "fmt"
+
+func Merge(a, b map[string]string) map[string]string {
+	result := make(map[string]string, len(a)+len(b))
+
+	for k, v := range a {
+		result[k] = v
+	}
+	for k, v := range b {
+		result[k] = v
+	}
+
+	return result
+}
+
+func Selector(labels map[string]string) string {
+	selector := make([]byte, 0, 64)
+	separator := ""
+
+	for k, v := range labels {
+		selector = fmt.Appendf(selector, "%s%s=%s", separator, k, v)
+
+		// Do not print separator on first element
+		separator = ","
+	}
+
+	return string(selector)
+}