add transformer plugins

pkg/commands/build/build.go

@@ -62,7 +62,8 @@ url examples:
 func NewCmdBuild(
 	out io.Writer, fs fs.FileSystem,
 	rf *resmap.Factory,
-	ptf transformer.Factory) *cobra.Command {
+	ptf transformer.Factory,
+	b bool) *cobra.Command {
 	var o Options
 
 	cmd := &cobra.Command{
@@ -75,7 +76,7 @@ func NewCmdBuild(
 			if err != nil {
 				return err
 			}
-			return o.RunBuild(out, fs, rf, ptf)
+			return o.RunBuild(out, fs, rf, ptf, b)
 		},
 	}
 	cmd.Flags().StringVarP(
@@ -102,13 +103,14 @@ func (o *Options) Validate(args []string) error {
 // RunBuild runs build command.
 func (o *Options) RunBuild(
 	out io.Writer, fSys fs.FileSystem,
-	rf *resmap.Factory, ptf transformer.Factory) error {
+	rf *resmap.Factory, ptf transformer.Factory,
+	b bool) error {
 	ldr, err := loader.NewLoader(o.kustomizationPath, fSys)
 	if err != nil {
 		return err
 	}
 	defer ldr.Cleanup()
-	kt, err := target.NewKustTarget(ldr, rf, ptf)
+	kt, err := target.NewKustTarget(ldr, rf, ptf, b)
 	if err != nil {
 		return err
 	}

pkg/commands/commands.go

@@ -68,7 +68,7 @@ See https://sigs.k8s.io/kustomize
 		build.NewCmdBuild(
 			stdOut, fSys,
 			resmap.NewFactory(resource.NewFactory(uf)),
-			transformer.NewFactoryImpl()),
+			transformer.NewFactoryImpl(), genMetaArgs.PluginConfig.GoEnabled),
 		edit.NewCmdEdit(fSys, validator.NewKustValidator(), uf),
 		misc.NewCmdConfig(fSys),
 		misc.NewCmdVersion(stdOut),

pkg/pgmconfig/constants.go

@@ -28,5 +28,6 @@ var KustomizationFileNames = []string{
 }
 
 const (
-	PgmName = "kustomize"
+	PgmName    = "kustomize"
+	PluginsDir = "plugins"
 )

pkg/plugins/transformers.go

@@ -0,0 +1,95 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package plugins
+
+import (
+	"fmt"
+	"path/filepath"
+	"plugin"
+
+	"github.com/pkg/errors"
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"sigs.k8s.io/kustomize/pkg/pgmconfig"
+	"sigs.k8s.io/kustomize/pkg/resid"
+	"sigs.k8s.io/kustomize/pkg/resmap"
+	"sigs.k8s.io/kustomize/pkg/resource"
+	"sigs.k8s.io/kustomize/pkg/transformers"
+)
+
+const transformerSymbol = "Transformer"
+
+type Configurable interface {
+	Config(k ifc.Kunstructured) error
+}
+
+type transformerLoader struct {
+	pluginDir string
+	enabled   bool
+}
+
+func NewTransformerLoader(b bool) transformerLoader {
+	return transformerLoader{
+		pluginDir: filepath.Join(pgmconfig.ConfigRoot(), pgmconfig.PluginsDir),
+		enabled:   b,
+	}
+}
+
+func (l transformerLoader) Load(rm resmap.ResMap) ([]transformers.Transformer, error) {
+	if len(rm) == 0 {
+		return nil, nil
+	}
+	if !l.enabled {
+		return nil, fmt.Errorf("plugin is not enabled")
+	}
+	var result []transformers.Transformer
+	for id, res := range rm {
+		t, err := l.load(id, res)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, t)
+	}
+	return result, nil
+}
+
+func (l transformerLoader) load(id resid.ResId, res *resource.Resource) (transformers.Transformer, error) {
+	fileName := filepath.Join(l.pluginDir, id.Gvk().Kind+".so")
+	goPlugin, err := plugin.Open(fileName)
+	if err != nil {
+		return nil, fmt.Errorf("plugin %s file not opened", fileName)
+	}
+
+	symbol, err := goPlugin.Lookup(transformerSymbol)
+	if err != nil {
+		return nil, fmt.Errorf("plugin %s fails lookup", fileName)
+	}
+
+	c, ok := symbol.(Configurable)
+	if !ok {
+		return nil, fmt.Errorf("plugin %s not configurable", fileName)
+	}
+	err = c.Config(res)
+	if err != nil {
+		return nil, errors.Wrapf(err, "plugin %s fails configuration", fileName)
+	}
+
+	t, ok := c.(transformers.Transformer)
+	if !ok {
+		return nil, fmt.Errorf("plugin %s not a transformer", fileName)
+	}
+	return t, nil
+}

pkg/target/kusttarget.go

@@ -21,9 +21,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"os"
-	"path/filepath"
-	"plugin"
 	"strings"
 
 	"github.com/ghodss/yaml"
@@ -34,6 +31,7 @@ import (
 	interror "sigs.k8s.io/kustomize/pkg/internal/error"
 	patchtransformer "sigs.k8s.io/kustomize/pkg/patch/transformer"
 	"sigs.k8s.io/kustomize/pkg/pgmconfig"
+	"sigs.k8s.io/kustomize/pkg/plugins"
 	"sigs.k8s.io/kustomize/pkg/resmap"
 	"sigs.k8s.io/kustomize/pkg/resource"
 	"sigs.k8s.io/kustomize/pkg/transformers"
@@ -43,17 +41,19 @@ import (
 
 // KustTarget encapsulates the entirety of a kustomization build.
 type KustTarget struct {
-	kustomization *types.Kustomization
-	ldr           ifc.Loader
-	rFactory      *resmap.Factory
-	tFactory      transformer.Factory
+	kustomization   *types.Kustomization
+	ldr             ifc.Loader
+	rFactory        *resmap.Factory
+	tFactory        transformer.Factory
+	goPluginEnabled bool
 }
 
 // NewKustTarget returns a new instance of KustTarget primed with a Loader.
 func NewKustTarget(
 	ldr ifc.Loader,
 	rFactory *resmap.Factory,
-	tFactory transformer.Factory) (*KustTarget, error) {
+	tFactory transformer.Factory,
+	b bool) (*KustTarget, error) {
 	content, err := loadKustFile(ldr)
 	if err != nil {
 		return nil, err
@@ -71,10 +71,11 @@ func NewKustTarget(
 				strings.Join(errs, "\n"), ldr.Root())
 	}
 	return &KustTarget{
-		kustomization: &k,
-		ldr:           ldr,
-		rFactory:      rFactory,
-		tFactory:      tFactory,
+		kustomization:   &k,
+		ldr:             ldr,
+		rFactory:        rFactory,
+		tFactory:        tFactory,
+		goPluginEnabled: b,
 	}, nil
 }
 
@@ -255,7 +256,7 @@ func (kt *KustTarget) accumulateBases() (
 			continue
 		}
 		subKt, err := NewKustTarget(
-			ldr, kt.rFactory, kt.tFactory)
+			ldr, kt.rFactory, kt.tFactory, kt.goPluginEnabled)
 		if err != nil {
 			errs.Append(errors.Wrap(err, "couldn't make target for "+path))
 			ldr.Cleanup()
@@ -331,48 +332,11 @@ func (kt *KustTarget) newTransformer(
 }
 
 func (kt *KustTarget) loadTransformerPlugins() ([]transformers.Transformer, error) {
-	var result []transformers.Transformer
-
-	pc := types.PluginConfig{
-		DirectoryPath: os.Getenv("GOPATH"),
-		GoEnabled:     true}
-
-	root := filepath.Join(
-		pc.DirectoryPath, "src", "sigs.k8s.io", "kustomize", "plugins")
-
-	if !pc.GoEnabled {
-		return nil, fmt.Errorf("plugins not enabled")
-	}
-
 	transformerPluginConfigs, err := kt.rFactory.FromFiles(
 		kt.ldr, kt.kustomization.Transformers)
-
-	for id, res := range transformerPluginConfigs {
-		fileName := filepath.Join(root, id.Gvk().Kind+".so")
-		goPlugin, err := plugin.Open(fileName)
-		if err != nil {
-			return nil, fmt.Errorf("plugin %s file not opened", fileName)
-		}
-		symbol, err := goPlugin.Lookup("Transformer")
-		if err != nil {
-			return nil, fmt.Errorf("plugin %s fails lookup", fileName)
-		}
-		c, ok := symbol.(transformers.Configurable)
-		if !ok {
-			return nil, fmt.Errorf("plugin %s not configurable", fileName)
-		}
-		err = c.Config(res)
-		if err != nil {
-			return nil, errors.Wrapf(err, "plugin %s fails configuration", fileName)
-		}
-		t, ok := c.(transformers.Transformer)
-		if !ok {
-			return nil, fmt.Errorf("plugin %s not a transformer", fileName)
-		}
-
-		result = append(result, t)
-		fmt.Printf("Added plugin %s\n", fileName)
-
+	if err != nil {
+		return nil, err
 	}
-	return result, err
+	tl := plugins.NewTransformerLoader(kt.goPluginEnabled)
+	return tl.Load(transformerPluginConfigs)
 }

pkg/target/kusttarget_test.go

@@ -204,7 +204,7 @@ func TestResources(t *testing.T) {
 }
 
 func TestKustomizationNotFound(t *testing.T) {
-	_, err := NewKustTarget(loadertest.NewFakeLoader("/foo"), nil, nil)
+	_, err := NewKustTarget(loadertest.NewFakeLoader("/foo"), nil, nil, false)
 	if err == nil {
 		t.Fatalf("expected an error")
 	}

pkg/target/kusttestharness_test.go

@@ -40,6 +40,7 @@ type KustTestHarness struct {
 	t   *testing.T
 	rf  *resmap.Factory
 	ldr loadertest.FakeLoader
+	b   bool
 }
 
 func NewKustTestHarness(t *testing.T, path string) *KustTestHarness {
@@ -55,12 +56,13 @@ func NewKustTestHarnessWithPluginConfig(
 		rf: resmap.NewFactory(resource.NewFactory(
 			kunstruct.NewKunstructuredFactoryWithGeneratorArgs(
 				&types.GeneratorMetaArgs{PluginConfig: config}))),
-		ldr: loadertest.NewFakeLoader(path)}
+		ldr: loadertest.NewFakeLoader(path),
+		b:   config.GoEnabled}
 }
 
 func (th *KustTestHarness) makeKustTarget() *KustTarget {
 	kt, err := NewKustTarget(
-		th.ldr, th.rf, transformer.NewFactoryImpl())
+		th.ldr, th.rf, transformer.NewFactoryImpl(), th.b)
 	if err != nil {
 		th.t.Fatalf("Unexpected construction error %v", err)
 	}

pkg/target/transformerplugin_test.go

@@ -14,8 +14,14 @@ limitations under the License.
 package target_test
 
 import (
-	"sigs.k8s.io/kustomize/pkg/types"
+	"os"
+	"os/exec"
+	"path/filepath"
 	"testing"
+
+	"fmt"
+	"sigs.k8s.io/kustomize/pkg/pgmconfig"
+	"sigs.k8s.io/kustomize/pkg/types"
 )
 
 func writeDeployment(th *KustTestHarness, path string) {
@@ -55,7 +61,45 @@ metadata:
 `)
 }
 
+func buildGoPlugins(dir, filename string) error {
+	commands := []string{
+		"build",
+		"-buildmode",
+		"plugin",
+		"-tags=plugin",
+		"-o",
+		filename + ".so",
+		filename + ".go",
+	}
+	goBin := filepath.Join(os.Getenv("GOROOT"), "bin", "go")
+	if _, err := os.Stat(goBin); err != nil {
+		return fmt.Errorf("go binary not found %s", goBin)
+	}
+	cmd := exec.Command(goBin, commands...)
+	cmd.Env = os.Environ()
+	cmd.Dir = filepath.Join(dir, "kustomize", "plugins")
+
+	return cmd.Run()
+}
+
 func TestOrderedTransformers(t *testing.T) {
+	dir, err := filepath.Abs("../../..")
+	if err != nil {
+		t.Errorf("unexpected error %v", err)
+	}
+	os.Setenv(pgmconfig.XDG_CONFIG_HOME, dir)
+	defer os.Unsetenv(pgmconfig.XDG_CONFIG_HOME)
+
+	err = buildGoPlugins(dir, "StringPrefixer")
+	if err != nil {
+		t.Errorf("unexpected error %v", err)
+	}
+
+	err = buildGoPlugins(dir, "DatePrefixer")
+	if err != nil {
+		t.Errorf("unexpected error %v", err)
+	}
+
 	th := NewKustTestHarnessWithPluginConfig(
 		t, "/app", types.PluginConfig{GoEnabled: true})
 	th.writeK("/app", `

pkg/transformers/transformer.go

@@ -18,7 +18,6 @@ limitations under the License.
 package transformers
 
 import (
-	"sigs.k8s.io/kustomize/pkg/ifc"
 	"sigs.k8s.io/kustomize/pkg/resmap"
 )
 
@@ -27,7 +26,3 @@ type Transformer interface {
 	// Transform modifies data in the argument, e.g. adding labels to resources that can be labelled.
 	Transform(m resmap.ResMap) error
 }
-
-type Configurable interface {
-	Config(k ifc.Kunstructured) error
-}