add persistent proxy/visitor store with CRUD API and web UI (#5188)

pkg/util/util/util.go

@@ -134,3 +134,12 @@ func RandomSleep(duration time.Duration, minRatio, maxRatio float64) time.Durati
 func ConstantTimeEqString(a, b string) bool {
 	return subtle.ConstantTimeCompare([]byte(a), []byte(b)) == 1
 }
+
+// ClonePtr returns a pointer to a copied value. If v is nil, it returns nil.
+func ClonePtr[T any](v *T) *T {
+	if v == nil {
+		return nil
+	}
+	out := *v
+	return &out
+}

pkg/util/util/util_test.go

@@ -41,3 +41,16 @@ func TestParseRangeNumbers(t *testing.T) {
 	_, err = ParseRangeNumbers("3-a")
 	require.Error(err)
 }
+
+func TestClonePtr(t *testing.T) {
+	require := require.New(t)
+
+	var nilInt *int
+	require.Nil(ClonePtr(nilInt))
+
+	v := 42
+	cloned := ClonePtr(&v)
+	require.NotNil(cloned)
+	require.Equal(v, *cloned)
+	require.NotSame(&v, cloned)
+}