Cleanup the replica plugin implementation.

pkg/replica/replica.go

@@ -1,13 +0,0 @@
-package replica
-
-// Replica specifies a modification to a replica config.
-// The number of replicas of a resource whose name matches will be set to count.
-// This struct is used by the ReplicaCountTransform, and is meant to supplement
-// the existing patch functionality with a simpler syntax for replica configuration.
-type Replica struct {
-	// The name of the resource to change the replica count
-	Name string `json:"name,omitempty" yaml:"name,omitempty"`
-
-	// The number of replicas required.
-	Count uint `json:"count,omitempty" yaml:"count,omitempty"`
-}

pkg/target/kusttarget_configplugin.go

@@ -7,7 +7,6 @@ import (
 	"github.com/pkg/errors"
 	"sigs.k8s.io/kustomize/pkg/image"
 	"sigs.k8s.io/kustomize/pkg/plugins"
-	"sigs.k8s.io/kustomize/pkg/replica"
 	"sigs.k8s.io/kustomize/pkg/transformers"
 	"sigs.k8s.io/kustomize/pkg/transformers/config"
 	"sigs.k8s.io/kustomize/pkg/types"
@@ -80,6 +79,7 @@ func (kt *KustTarget) configureBuiltinTransformers(
 		}
 		result = append(result, r...)
 	}
+
 	return result, nil
 }
 
@@ -239,12 +239,10 @@ func (kt *KustTarget) configureBuiltinReplicaCountTransformer(
 	tConfig *config.TransformerConfig) (
 	result []transformers.Transformer, err error) {
 	var c struct {
-		Replica    replica.Replica
+		Replica types.Replica
-		FieldSpecs []config.FieldSpec
 	}
 	for _, args := range kt.kustomization.Replicas {
 		c.Replica = args
-		c.FieldSpecs = tConfig.Replicas
 		p := builtin.NewReplicaCountTransformerPlugin()
 		err = kt.configureBuiltinPlugin(p, c, "replica")
 		if err != nil {

pkg/transformers/config/transformerconfig.go

@@ -35,7 +35,6 @@ type TransformerConfig struct {
 	NameReference     nbrSlice `json:"nameReference,omitempty" yaml:"nameReference,omitempty"`
 	VarReference      fsSlice  `json:"varReference,omitempty" yaml:"varReference,omitempty"`
 	Images            fsSlice  `json:"images,omitempty" yaml:"images,omitempty"`
-	Replicas          fsSlice  `json:"replicas,omitempty" yaml:"replicas,omitempty"`
 }
 
 // MakeEmptyConfig returns an empty TransformerConfig object
@@ -62,7 +61,6 @@ func (t *TransformerConfig) sortFields() {
 	sort.Sort(t.NameReference)
 	sort.Sort(t.VarReference)
 	sort.Sort(t.Images)
-	sort.Sort(t.Replicas)
 }
 
 // AddPrefixFieldSpec adds a FieldSpec to NamePrefix

pkg/types/kustomization.go

@@ -22,7 +22,6 @@ import (
 
 	"sigs.k8s.io/kustomize/pkg/gvk"
 	"sigs.k8s.io/kustomize/pkg/image"
-	"sigs.k8s.io/kustomize/pkg/replica"
 )
 
 const (
@@ -82,7 +81,7 @@ type Kustomization struct {
 
 	// Replicas is a list of {resourcename, count} that allows for simpler replica
 	// specification. This can also be done with a patch.
-	Replicas []replica.Replica `json:"replicas,omitempty" yaml:"replicas,omitempty"`
+	Replicas []Replica `json:"replicas,omitempty" yaml:"replicas,omitempty"`
 
 	// Vars allow things modified by kustomize to be injected into a
 	// container specification. A var is a name (e.g. FOO) associated
@@ -360,3 +359,15 @@ type PatchTarget struct {
 // stategic merge patch with the format
 // https://github.com/kubernetes/community/blob/master/contributors/devel/strategic-merge-patch.md
 type PatchStrategicMerge string
+
+// Replica specifies a modification to a replica config.
+// The number of replicas of a resource whose name matches will be set to count.
+// This struct is used by the ReplicaCountTransform, and is meant to supplement
+// the existing patch functionality with a simpler syntax for replica configuration.
+type Replica struct {
+	// The name of the resource to change the replica count
+	Name string `json:"name,omitempty" yaml:"name,omitempty"`
+
+	// The number of replicas required.
+	Count uint `json:"count,omitempty" yaml:"count,omitempty"`
+}

plugin/builtin/ReplicaCountTransformer.go

@@ -2,20 +2,24 @@
 package builtin
 
 import (
-	"github.com/pkg/errors"
+	"fmt"
+
 	"sigs.k8s.io/kustomize/pkg/ifc"
-	"sigs.k8s.io/kustomize/pkg/replica"
 	"sigs.k8s.io/kustomize/pkg/resid"
 	"sigs.k8s.io/kustomize/pkg/resmap"
-	"sigs.k8s.io/kustomize/pkg/transformers/config"
+	"sigs.k8s.io/kustomize/pkg/types"
 	"sigs.k8s.io/yaml"
 )
 
-// Find matching replicas declarations and replace
+const (
-// the count.
+	fldReplica = "replicas"
+	fldSpec    = "spec"
+)
+
+// Find matching replicas declarations and replace the count.
+// Eases the kustomization configuration of replica changes.
 type ReplicaCountTransformerPlugin struct {
-	Replica    replica.Replica    `json:"replica,omitempty" yaml:"replica,omitempty"`
+	Replica types.Replica `json:"replica,omitempty" yaml:"replica,omitempty"`
-	FieldSpecs []config.FieldSpec `json:"fieldSpecs,omitempty" yaml:"fieldSpecs,omitempty"`
 }
 
 func NewReplicaCountTransformerPlugin() *ReplicaCountTransformerPlugin {
@@ -25,8 +29,7 @@ func NewReplicaCountTransformerPlugin() *ReplicaCountTransformerPlugin {
 func (p *ReplicaCountTransformerPlugin) Config(
 	ldr ifc.Loader, rf *resmap.Factory, c []byte) (err error) {
 
-	p.Replica = replica.Replica{}
+	p.Replica = types.Replica{}
-	p.FieldSpecs = nil
 	return yaml.Unmarshal(c, p)
 }
 
@@ -36,21 +39,20 @@ func (p *ReplicaCountTransformerPlugin) Transform(m resmap.ResMap) error {
 	}
 
 	for _, r := range m.GetMatchingIds(matcher) {
-		kMap := m[r].Kunstructured.Map()
+		kMap := m[r].Map()
 
-		specInterface, ok := kMap["spec"]
+		specInterface, ok := kMap[fldSpec]
 		if !ok {
-			return errors.New("'spec' not specified, replicas cannot be modified")
+			return fmt.Errorf("object %s missing field %s, cannot update %s",
+				p.Replica.Name, fldSpec, fldReplica)
 		}
 
 		if spec, ok := specInterface.(map[string]interface{}); ok {
-			spec["replicas"] = p.Replica.Count
+			spec[fldReplica] = p.Replica.Count
-			kMap["spec"] = spec
+			kMap[fldSpec] = spec
 		} else {
-			return errors.New("'spec' not structured as expected")
+			return fmt.Errorf("object %s has a malformed %s", p.Replica.Name, fldSpec)
 		}
-
-		m[r].Kunstructured.SetMap(kMap)
 	}
 
 	return nil

plugin/builtin/replicacounttransformer/ReplicaCountTransformer.go

@@ -5,20 +5,24 @@
 package main
 
 import (
-	"github.com/pkg/errors"
+	"fmt"
+
 	"sigs.k8s.io/kustomize/pkg/ifc"
-	"sigs.k8s.io/kustomize/pkg/replica"
 	"sigs.k8s.io/kustomize/pkg/resid"
 	"sigs.k8s.io/kustomize/pkg/resmap"
-	"sigs.k8s.io/kustomize/pkg/transformers/config"
+	"sigs.k8s.io/kustomize/pkg/types"
 	"sigs.k8s.io/yaml"
 )
 
+const (
+	fldReplica = "replicas"
+	fldSpec    = "spec"
+)
+
 // Find matching replicas declarations and replace the count.
 // Eases the kustomization configuration of replica changes.
 type plugin struct {
-	Replica    replica.Replica    `json:"replica,omitempty" yaml:"replica,omitempty"`
+	Replica types.Replica `json:"replica,omitempty" yaml:"replica,omitempty"`
-	FieldSpecs []config.FieldSpec `json:"fieldSpecs,omitempty" yaml:"fieldSpecs,omitempty"`
 }
 
 var KustomizePlugin plugin
@@ -26,8 +30,7 @@ var KustomizePlugin plugin
 func (p *plugin) Config(
 	ldr ifc.Loader, rf *resmap.Factory, c []byte) (err error) {
 
-	p.Replica = replica.Replica{}
+	p.Replica = types.Replica{}
-	p.FieldSpecs = nil
 	return yaml.Unmarshal(c, p)
 }
 
@@ -37,21 +40,20 @@ func (p *plugin) Transform(m resmap.ResMap) error {
 	}
 
 	for _, r := range m.GetMatchingIds(matcher) {
-		kMap := m[r].Kunstructured.Map()
+		kMap := m[r].Map()
 
-		specInterface, ok := kMap["spec"]
+		specInterface, ok := kMap[fldSpec]
 		if !ok {
-			return errors.New("'spec' not specified, replicas cannot be modified")
+			return fmt.Errorf("object %s missing field %s, cannot update %s",
+				p.Replica.Name, fldSpec, fldReplica)
 		}
 
 		if spec, ok := specInterface.(map[string]interface{}); ok {
-			spec["replicas"] = p.Replica.Count
+			spec[fldReplica] = p.Replica.Count
-			kMap["spec"] = spec
+			kMap[fldSpec] = spec
 		} else {
-			return errors.New("'spec' not structured as expected")
+			return fmt.Errorf("object %s has a malformed %s", p.Replica.Name, fldSpec)
 		}
-
-		m[r].Kunstructured.SetMap(kMap)
 	}
 
 	return nil