Add ConfigMapGenerator and test.

pkg/resmap/legacygeneratorargs.go

@@ -1,6 +1,8 @@
 package resmap
 
 import (
+	"strings"
+
 	"sigs.k8s.io/kustomize/pkg/ifc"
 	"sigs.k8s.io/kustomize/pkg/types"
 )
@@ -10,17 +12,26 @@ func GeneratorArgsFromKunstruct(k ifc.Kunstructured) (
 	result.Name = k.GetName()
 	// TODO: validate behavior values.
 	result.Behavior, err = k.GetFieldValue("behavior")
-	if err != nil {
+	if !isAcceptableError(err) {
 		return
 	}
 	result.EnvSources, err = k.GetStringSlice("envFiles")
-	if err != nil {
+	if !isAcceptableError(err) {
 		return
 	}
 	result.FileSources, err = k.GetStringSlice("valueFiles")
-	if err != nil {
+	if !isAcceptableError(err) {
 		return
 	}
 	result.LiteralSources, err = k.GetStringSlice("literals")
+	if !isAcceptableError(err) {
 		return
 	}
+	err = nil
+	return
+}
+
+func isAcceptableError(err error) bool {
+	return err == nil ||
+		strings.HasPrefix(err.Error(), "no field named")
+}

plugin/builtin/ConfigMapGenerator.go

@@ -0,0 +1,32 @@
+// +build plugin
+
+package main
+
+import (
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"sigs.k8s.io/kustomize/pkg/resmap"
+	"sigs.k8s.io/kustomize/pkg/types"
+)
+
+type plugin struct {
+	ldr     ifc.Loader
+	rf      *resmap.Factory
+	options types.GeneratorOptions
+	args    types.ConfigMapArgs
+}
+
+var KustomizePlugin plugin
+
+func (p *plugin) Config(
+	ldr ifc.Loader, rf *resmap.Factory, k ifc.Kunstructured) (err error) {
+	p.ldr = ldr
+	p.rf = rf
+	p.args.GeneratorArgs, err = resmap.GeneratorArgsFromKunstruct(k)
+	return
+}
+
+func (p *plugin) Generate() (resmap.ResMap, error) {
+	argsList := make([]types.ConfigMapArgs, 1)
+	argsList[0] = p.args
+	return p.rf.NewResMapFromConfigMapArgs(p.ldr, &p.options, argsList)
+}

plugin/builtin/ConfigMapGenerator_test.go

@@ -0,0 +1,53 @@
+package builtin
+
+import (
+	"testing"
+
+	"sigs.k8s.io/kustomize/internal/plugintest"
+	"sigs.k8s.io/kustomize/k8sdeps/kv/plugin"
+	"sigs.k8s.io/kustomize/pkg/kusttest"
+	"sigs.k8s.io/kustomize/pkg/loader"
+)
+
+func TestConfigMapGenerator(t *testing.T) {
+	tc := plugintest_test.NewPluginTestEnv(t).Set()
+	defer tc.Reset()
+
+	tc.BuildGoPlugin(
+		"builtin", "", "ConfigMapGenerator")
+
+	th := kusttest_test.NewKustTestHarnessFull(
+		t, "/app", loader.RestrictionRootOnly, plugin.ActivePluginConfig())
+
+	th.WriteF("/app/devops.env", `
+SERVICE_PORT=32
+`)
+	th.WriteF("/app/uxteam.env", `
+COLOR=red
+`)
+
+	rm := th.LoadAndRunGenerator(`
+apiVersion: builtin
+kind: ConfigMapGenerator
+metadata:
+  name: myMap
+envFiles:
+- devops.env
+- uxteam.env
+literals:
+- FRUIT=apple
+- VEGETABLE=carrot
+`)
+
+	th.AssertActualEqualsExpected(rm, `
+apiVersion: v1
+data:
+  COLOR: red
+  FRUIT: apple
+  SERVICE_PORT: "32"
+  VEGETABLE: carrot
+kind: ConfigMap
+metadata:
+  name: myMap
+`)
+}