k3s/vendor/sigs.k8s.io/kustomize/api/internal/plugins/builtinconfig/namebackreferences.go

100 lines
2.7 KiB
Go

// Copyright 2019 The Kubernetes Authors.
// SPDX-License-Identifier: Apache-2.0
package builtinconfig
import (
"strings"
"sigs.k8s.io/kustomize/api/types"
"sigs.k8s.io/kustomize/kyaml/resid"
)
// NameBackReferences is an association between a gvk.GVK (a ReferralTarget)
// and a list of Referrers that could refer to it.
//
// It is used to handle name changes, and can be thought of as a
// a contact list. If you change your own contact info (name,
// phone number, etc.), you must tell your contacts or they won't
// know about the change.
//
// For example, ConfigMaps can be used by Pods and everything that
// contains a Pod; Deployment, Job, StatefulSet, etc.
// The ConfigMap is the ReferralTarget, the others are Referrers.
//
// If the the name of a ConfigMap instance changed from 'alice' to 'bob',
// one must
// - visit all objects that could refer to the ConfigMap (the Referrers)
// - see if they mention 'alice',
// - if so, change the Referrer's name reference to 'bob'.
//
// The NameBackReferences instance to aid in this could look like
// {
// kind: ConfigMap
// version: v1
// fieldSpecs:
// - kind: Pod
// version: v1
// path: spec/volumes/configMap/name
// - kind: Deployment
// path: spec/template/spec/volumes/configMap/name
// - kind: Job
// path: spec/template/spec/volumes/configMap/name
// (etc.)
// }
type NameBackReferences struct {
resid.Gvk `json:",inline,omitempty" yaml:",inline,omitempty"`
// TODO: rename json 'fieldSpecs' to 'referrers' for clarity.
// This will, however, break anyone using a custom config.
Referrers types.FsSlice `json:"fieldSpecs,omitempty" yaml:"fieldSpecs,omitempty"`
}
func (n NameBackReferences) String() string {
var r []string
for _, f := range n.Referrers {
r = append(r, f.String())
}
return n.Gvk.String() + ": (\n" +
strings.Join(r, "\n") + "\n)"
}
type nbrSlice []NameBackReferences
func (s nbrSlice) Len() int { return len(s) }
func (s nbrSlice) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
func (s nbrSlice) Less(i, j int) bool {
return s[i].Gvk.IsLessThan(s[j].Gvk)
}
func (s nbrSlice) mergeAll(o nbrSlice) (result nbrSlice, err error) {
result = s
for _, r := range o {
result, err = result.mergeOne(r)
if err != nil {
return nil, err
}
}
return result, nil
}
func (s nbrSlice) mergeOne(other NameBackReferences) (nbrSlice, error) {
var result nbrSlice
var err error
found := false
for _, c := range s {
if c.Gvk.Equals(other.Gvk) {
c.Referrers, err = c.Referrers.MergeAll(other.Referrers)
if err != nil {
return nil, err
}
found = true
}
result = append(result, c)
}
if !found {
result = append(result, other)
}
return result, nil
}