k3s/vendor/sigs.k8s.io/kustomize/api/internal/target/multitransformer.go

86 lines
2.1 KiB
Go

// Copyright 2019 The Kubernetes Authors.
// SPDX-License-Identifier: Apache-2.0
package target
import (
"fmt"
"sigs.k8s.io/kustomize/api/resmap"
)
// multiTransformer contains a list of transformers.
type multiTransformer struct {
transformers []resmap.Transformer
checkConflictEnabled bool
}
var _ resmap.Transformer = &multiTransformer{}
// newMultiTransformer constructs a multiTransformer.
func newMultiTransformer(t []resmap.Transformer) resmap.Transformer {
r := &multiTransformer{
transformers: make([]resmap.Transformer, len(t)),
checkConflictEnabled: false}
copy(r.transformers, t)
return r
}
// Transform applies the member transformers in order to the resources,
// optionally detecting and erroring on commutation conflict.
func (o *multiTransformer) Transform(m resmap.ResMap) error {
if o.checkConflictEnabled {
return o.transformWithCheckConflict(m)
}
return o.transform(m)
}
func (o *multiTransformer) transform(m resmap.ResMap) error {
for _, t := range o.transformers {
err := t.Transform(m)
if err != nil {
return err
}
}
for _, r := range m.Resources() {
empty, err := r.IsEmpty()
if err != nil {
return err
}
if empty {
err := m.Remove(r.CurId())
if err != nil {
return err
}
}
}
return nil
}
// Of the len(o.transformers)! possible transformer orderings, compare to a reversed order.
// A spot check to perform when the transformations are supposed to be commutative.
// Fail if there's a difference in the result.
func (o *multiTransformer) transformWithCheckConflict(m resmap.ResMap) error {
mcopy := m.DeepCopy()
err := o.transform(m)
if err != nil {
return err
}
o.reverseTransformers()
err = o.transform(mcopy)
if err != nil {
return err
}
err = m.ErrorIfNotEqualSets(mcopy)
if err != nil {
return fmt.Errorf("found conflict between different patches\n%v", err)
}
return nil
}
func (o *multiTransformer) reverseTransformers() {
for i, j := 0, len(o.transformers)-1; i < j; i, j = i+1, j-1 {
o.transformers[i], o.transformers[j] = o.transformers[j], o.transformers[i]
}
}