add replacement transformer

api/types/replacement.go

@@ -0,0 +1,27 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package types
+
+// Replacement defines how to perform a substitution
+// where it is from and where it is to.
+type Replacement struct {
+	Source *ReplSource `json:"source" yaml:"source"`
+	Target *ReplTarget `json:"target" yaml:"target"`
+}
+
+// ReplSource defines where a substitution is from
+// It can from two different kinds of sources
+//  - from a field of one resource
+//  - from a string
+type ReplSource struct {
+	ObjRef   *Target `json:"objref,omitempty" yaml:"objref,omitempty"`
+	FieldRef string  `json:"fieldref,omitempty" yaml:"fiedldref,omitempty"`
+	Value    string  `json:"value,omitempty" yaml:"value,omitempty"`
+}
+
+// ReplTarget defines where a substitution is to.
+type ReplTarget struct {
+	ObjRef    *Selector `json:"objref,omitempty" yaml:"objref,omitempty"`
+	FieldRefs []string  `json:"fieldrefs,omitempty" yaml:"fieldrefs,omitempty"`
+}