update fieldspec name value based on nameReference map

Author: yuwenma

functions/go/gcp-set-default-name/README.md

@@ -1,8 +1,19 @@
 # set-default-name
 
 ### Feature
-`set-default-name` does a simple task: cruelly updates the resource metadata name or name references if `metadata.name`
-match the fieldSpec list in `fieldspec/customName.go`. 
+`set-default-name` sets two types of default name values:
 
-### Warning
-!!! Be careful when using this function.
+- It sets the `metadata.name` fields for white listed KRM resources.
+- It sets custom field specs to their referred `metadata.name` fields.  
+
+In case one, you use `ConfigMap` to set the name. The ConfigMap should
+contain a `.data.name` field and be provided as input resource. If the KRM 
+resources are not listed, their `'metadata.name` won't be updated. 
+The white list can be found in `./fieldspec/name.go`.
+
+In case two, you can find the nameReferences whiteliest in `./fieldspec/nameref.go`
+A `nameReference` contains a GVK and a list of referrals. The GVK gives 
+the resources' `metadata.data` to read, the `referral` lists the resource 
+field spec to update. This is different from kustomize nameReference, which 
+only updates referrals metadata.name field and requires the referrals and 
+referror have the same `metadata.name`.  

functions/go/gcp-set-default-name/builtin/backref.go

@@ -4,10 +4,12 @@ const (
 	NameReferenceFieldSpecs = `
 nameReference:
 - kind: RedisInstance
-  group: redis.cnrm.cloud.google.com/v1beta1
+  group: redis.cnrm.cloud.google.com
+  version: v1beta1
   fieldSpecs:
   - path: spec/displayName
     kind: RedisInstance
-    group: redis.cnrm.cloud.google.com/v1beta1
+    group: redis.cnrm.cloud.google.com
+    version: v1beta1
 `
 )

functions/go/gcp-set-default-name/fieldspec/nameref.go

@@ -1,4 +1,4 @@
-module github.com/GoogleContainerTools/kpt-functions-catalog/functions/go/set-project-id
+module github.com/GoogleContainerTools/kpt-functions-catalog/functions/go/gcp-set-default-name
 
 go 1.17
 

functions/go/gcp-set-default-name/go.mod

@@ -0,0 +1,85 @@
+package namereference
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+	"sigs.k8s.io/kustomize/api/filters/fieldspec"
+	"sigs.k8s.io/kustomize/api/resmap"
+	"sigs.k8s.io/kustomize/api/resource"
+	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/kio"
+	"sigs.k8s.io/kustomize/kyaml/resid"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+type UnlimitedNameRefFilter struct {
+	Referrer *resource.Resource
+	NameFieldToUpdate types.FieldSpec
+	ReferralTarget resid.Gvk
+	ReferralCandidates resmap.ResMap
+
+}
+
+func (f UnlimitedNameRefFilter) Filter(nodes []*yaml.RNode) ([]*yaml.RNode, error) {
+	return kio.FilterAll(yaml.FilterFunc(f.run)).Filter(nodes)
+}
+
+func (f UnlimitedNameRefFilter) run(node *yaml.RNode) (*yaml.RNode, error) {
+	if node.GetNamespace() != f.Referrer.GetNamespace() {
+		return nil, fmt.Errorf("not in the same namespace")
+	}
+	if err := node.PipeE(fieldspec.Filter{
+		FieldSpec: f.NameFieldToUpdate,
+		SetValue:  f.updateName,
+	}); err != nil {
+		return nil, errors.Wrapf(
+			err, "updating name reference in '%s' field of '%s'",
+			f.NameFieldToUpdate.Path, f.Referrer.CurId().String())
+	}
+	return node, nil
+}
+
+func (f UnlimitedNameRefFilter) updateName(node *yaml.RNode) error {
+	if yaml.IsMissingOrNull(node) {
+		return nil
+	}
+	referrals := doSieve(f.ReferralCandidates.Resources(), f.sameCurrentNamespaceAsReferrer())
+	if len(referrals) == 0 {
+		return nil
+	}
+	referral := referrals[0]
+	return node.PipeE(yaml.FieldSetter{StringValue: referral.GetName()})
+}
+
+type sieveFunc func(*resource.Resource) bool
+
+func doSieve(list []*resource.Resource, fn sieveFunc) (s []*resource.Resource) {
+	for _, r := range list {
+		if fn(r) {
+			s = append(s, r)
+		}
+	}
+	return
+}
+
+func (f UnlimitedNameRefFilter) sameCurrentNamespaceAsReferrer() sieveFunc {
+	referrerCurId := f.Referrer.CurId()
+	if referrerCurId.IsClusterScoped() {
+		// If the referrer is cluster-scoped, let anything through.
+		return func(_ *resource.Resource) bool {return true}
+	}
+	return func(r *resource.Resource) bool {
+		if r.CurId().IsClusterScoped() {
+			// Allow cluster-scoped through.
+			return true
+		}
+		if r.GetKind() == "ServiceAccount" {
+			// Allow service accounts through, even though they
+			// are in a namespace.  A RoleBinding in another namespace
+			// can reference them.
+			return true
+		}
+		return referrerCurId.IsNsEquals(r.CurId())
+	}
+}

functions/go/gcp-set-default-name/namereference/filter.go

@@ -1,23 +1,28 @@
-package builtin
+package namereference
 
 import (
 	"log"
 
-	"sigs.k8s.io/kustomize/api/filters/nameref"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/resource"
+	"sigs.k8s.io/kustomize/api/types"
 	"sigs.k8s.io/kustomize/kyaml/resid"
 )
 
 type nameReferenceTransformer struct {
 	backRefs []NameBackReferences
 }
 
-const doDebug = false
+type NameBackReferences struct {
+	resid.Gvk `json:",inline,omitempty" yaml:",inline,omitempty"`
+	Referrers types.FsSlice `json:"fieldSpecs,omitempty" yaml:"fieldSpecs,omitempty"`
+}
+
+type NbrSlice []NameBackReferences
 
 var _ resmap.Transformer = &nameReferenceTransformer{}
 
-type filterMap map[*resource.Resource][]nameref.Filter
+type filterMap map[*resource.Resource][]UnlimitedNameRefFilter
 
 func NewNameReferenceTransformer(
 	br []NameBackReferences) resmap.Transformer {
@@ -39,7 +44,6 @@ func (t *nameReferenceTransformer) Transform(m resmap.ResMap) error {
 			}
 		}
 	}
-
 	return nil
 }
 
@@ -55,7 +59,7 @@ func (t *nameReferenceTransformer) determineFilters(
 		for _, referrerSpec := range backReference.Referrers {
 			for i, res := range resources {
 				if resourceOrgIds[i].IsSelected(&referrerSpec.Gvk) {
-						fMap[res] = append(fMap[res], nameref.Filter{
+						fMap[res] = append(fMap[res], UnlimitedNameRefFilter{
 							NameFieldToUpdate: referrerSpec,
 							ReferralTarget: backReference.Gvk,
 						})

…-set-default-name/builtin/transformer.go …efault-name/namereference/transformer.gofunctions/go/gcp-set-default-name/builtin/transformer.go renamed to functions/go/gcp-set-default-name/namereference/transformer.go functions/go/gcp-set-default-name/builtin/transformer.go renamed to functions/go/gcp-set-default-name/namereference/transformer.go

@@ -3,8 +3,8 @@ package main
 import (
 	"fmt"
 
-	"github.com/GoogleContainerTools/kpt-functions-catalog/functions/go/set-project-id/builtin"
-	"github.com/GoogleContainerTools/kpt-functions-catalog/functions/go/set-project-id/fieldspec"
+	"github.com/GoogleContainerTools/kpt-functions-catalog/functions/go/gcp-set-default-name/fieldspec"
+	"github.com/GoogleContainerTools/kpt-functions-catalog/functions/go/gcp-set-default-name/namereference"
 	"sigs.k8s.io/kustomize/api/filters/fsslice"
 	"sigs.k8s.io/kustomize/api/konfig/builtinpluginconsts"
 	"sigs.k8s.io/kustomize/api/resmap"
@@ -55,7 +55,7 @@ func (p *CustomNameTransformer) Config(fnConfigNode *yaml.RNode) error {
 		return err
 	}
 	nameRefs := append(builtinNameRefFs.NameReference, customNameRefFs.NameReference...)
-	p.nameRefTransformer = builtin.NewNameReferenceTransformer(nameRefs)
+	p.nameRefTransformer = namereference.NewNameReferenceTransformer(nameRefs)
 	return nil
 }
 
@@ -74,7 +74,7 @@ func (p *CustomNameTransformer) Transform(m resmap.ResMap) error {
 }
 
 type NameBackRefs struct {
-	NameReference     builtin.NbrSlice      `json:"nameReference,omitempty" yaml:"nameReference,omitempty"`
+	NameReference     namereference.NbrSlice      `json:"nameReference,omitempty" yaml:"nameReference,omitempty"`
 }
 
 var _ kio.Filter = CustomFieldSpecFilter{}