Add ingress feature to controller (#5)

Co-authored-by: Maycon Santos <mlsmaycon@gmail.com>

internal/util/ptr.go

@@ -0,0 +1,6 @@
+package util
+
+// Ptr return pointer to any value for API purposes
+func Ptr[T any, PT *T](x T) PT {
+	return &x
+}

internal/util/slices.go

@@ -0,0 +1,41 @@
+package util
+
+// Contains return if y is in slice x
+func Contains[T comparable](x []T, y T) bool {
+	for _, v := range x {
+		if v == y {
+			return true
+		}
+	}
+	return false
+}
+
+// Without return all of x in same order without y
+func Without[T comparable](x []T, y T) []T {
+	var ret []T
+	for _, v := range x {
+		if v != y {
+			ret = append(ret, v)
+		}
+	}
+	return ret
+}
+
+// Equivalent return true if x and y are equal when sorted
+func Equivalent[T comparable](x, y []T) bool {
+	if len(x) != len(y) {
+		return false
+	}
+
+	mp := make(map[T]interface{})
+	for _, v := range x {
+		mp[v] = nil
+	}
+	for _, v := range y {
+		if _, ok := mp[v]; !ok {
+			return false
+		}
+	}
+
+	return true
+}