until stable: pin-dependency, update-vendor, update-bazel, lint-dep

vendor/sigs.k8s.io/kustomize/api/internal/plugins/loader/loader.go

@@ -0,0 +1,246 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package loader
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"plugin"
+	"reflect"
+	"strings"
+
+	"github.com/pkg/errors"
+	"sigs.k8s.io/kustomize/api/ifc"
+	"sigs.k8s.io/kustomize/api/internal/plugins/builtinhelpers"
+	"sigs.k8s.io/kustomize/api/internal/plugins/execplugin"
+	"sigs.k8s.io/kustomize/api/internal/plugins/fnplugin"
+	"sigs.k8s.io/kustomize/api/internal/plugins/utils"
+	"sigs.k8s.io/kustomize/api/konfig"
+	"sigs.k8s.io/kustomize/api/resid"
+	"sigs.k8s.io/kustomize/api/resmap"
+	"sigs.k8s.io/kustomize/api/resource"
+	"sigs.k8s.io/kustomize/api/types"
+)
+
+// Loader loads plugins using a file loader (a different loader).
+type Loader struct {
+	pc *types.PluginConfig
+	rf *resmap.Factory
+}
+
+func NewLoader(
+	pc *types.PluginConfig, rf *resmap.Factory) *Loader {
+	return &Loader{pc: pc, rf: rf}
+}
+
+func (l *Loader) LoadGenerators(
+	ldr ifc.Loader, v ifc.Validator, rm resmap.ResMap) ([]resmap.Generator, error) {
+	var result []resmap.Generator
+	for _, res := range rm.Resources() {
+		g, err := l.LoadGenerator(ldr, v, res)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, g)
+	}
+	return result, nil
+}
+
+func (l *Loader) LoadGenerator(
+	ldr ifc.Loader, v ifc.Validator, res *resource.Resource) (resmap.Generator, error) {
+	c, err := l.loadAndConfigurePlugin(ldr, v, res)
+	if err != nil {
+		return nil, err
+	}
+	g, ok := c.(resmap.Generator)
+	if !ok {
+		return nil, fmt.Errorf("plugin %s not a generator", res.OrgId())
+	}
+	return g, nil
+}
+
+func (l *Loader) LoadTransformers(
+	ldr ifc.Loader, v ifc.Validator, rm resmap.ResMap) ([]resmap.Transformer, error) {
+	var result []resmap.Transformer
+	for _, res := range rm.Resources() {
+		t, err := l.LoadTransformer(ldr, v, res)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, t)
+	}
+	return result, nil
+}
+
+func (l *Loader) LoadTransformer(
+	ldr ifc.Loader, v ifc.Validator, res *resource.Resource) (resmap.Transformer, error) {
+	c, err := l.loadAndConfigurePlugin(ldr, v, res)
+	if err != nil {
+		return nil, err
+	}
+	t, ok := c.(resmap.Transformer)
+	if !ok {
+		return nil, fmt.Errorf("plugin %s not a transformer", res.OrgId())
+	}
+	return t, nil
+}
+
+func relativePluginPath(id resid.ResId) string {
+	return filepath.Join(
+		id.Group,
+		id.Version,
+		strings.ToLower(id.Kind))
+}
+
+func AbsolutePluginPath(pc *types.PluginConfig, id resid.ResId) string {
+	return filepath.Join(
+		pc.AbsPluginHome, relativePluginPath(id), id.Kind)
+}
+
+func (l *Loader) absolutePluginPath(id resid.ResId) string {
+	return AbsolutePluginPath(l.pc, id)
+}
+
+func isBuiltinPlugin(res *resource.Resource) bool {
+	// TODO: the special string should appear in Group, not Version.
+	return res.GetGvk().Group == "" &&
+		res.GetGvk().Version == konfig.BuiltinPluginApiVersion
+}
+
+func (l *Loader) loadAndConfigurePlugin(
+	ldr ifc.Loader,
+	v ifc.Validator,
+	res *resource.Resource) (c resmap.Configurable, err error) {
+	if isBuiltinPlugin(res) {
+		switch l.pc.BpLoadingOptions {
+		case types.BploLoadFromFileSys:
+			c, err = l.loadPlugin(res)
+		case types.BploUseStaticallyLinked:
+			// Instead of looking for and loading a .so file,
+			// instantiate the plugin from a generated factory
+			// function (see "pluginator").  Being able to do this
+			// is what makes a plugin "builtin".
+			c, err = l.makeBuiltinPlugin(res.GetGvk())
+		default:
+			err = fmt.Errorf(
+				"unknown plugin loader behavior specified: %v",
+				l.pc.BpLoadingOptions)
+		}
+	} else {
+		switch l.pc.PluginRestrictions {
+		case types.PluginRestrictionsNone:
+			c, err = l.loadPlugin(res)
+		case types.PluginRestrictionsBuiltinsOnly:
+			err = types.NewErrOnlyBuiltinPluginsAllowed(res.OrgId().Kind)
+		default:
+			err = fmt.Errorf(
+				"unknown plugin restriction specified: %v",
+				l.pc.PluginRestrictions)
+		}
+	}
+	if err != nil {
+		return nil, err
+	}
+	yaml, err := res.AsYAML()
+	if err != nil {
+		return nil, errors.Wrapf(err, "marshalling yaml from res %s", res.OrgId())
+	}
+	err = c.Config(resmap.NewPluginHelpers(ldr, v, l.rf), yaml)
+	if err != nil {
+		return nil, errors.Wrapf(
+			err, "plugin %s fails configuration", res.OrgId())
+	}
+	return c, nil
+}
+
+func (l *Loader) makeBuiltinPlugin(r resid.Gvk) (resmap.Configurable, error) {
+	bpt := builtinhelpers.GetBuiltinPluginType(r.Kind)
+	if f, ok := builtinhelpers.GeneratorFactories[bpt]; ok {
+		return f(), nil
+	}
+	if f, ok := builtinhelpers.TransformerFactories[bpt]; ok {
+		return f(), nil
+	}
+	return nil, errors.Errorf("unable to load builtin %s", r)
+}
+
+func (l *Loader) loadPlugin(res *resource.Resource) (resmap.Configurable, error) {
+	spec := fnplugin.GetFunctionSpec(res)
+	if spec != nil {
+		return fnplugin.NewFnPlugin(&l.pc.FnpLoadingOptions), nil
+	}
+	return l.loadExecOrGoPlugin(res.OrgId())
+}
+
+func (l *Loader) loadExecOrGoPlugin(resId resid.ResId) (resmap.Configurable, error) {
+	// First try to load the plugin as an executable.
+	p := execplugin.NewExecPlugin(l.absolutePluginPath(resId))
+	err := p.ErrIfNotExecutable()
+	if err == nil {
+		return p, nil
+	}
+	if !os.IsNotExist(err) {
+		// The file exists, but something else is wrong,
+		// likely it's not executable.
+		// Assume the user forgot to set the exec bit,
+		// and return an error, rather than adding ".so"
+		// to the name and attempting to load it as a Go
+		// plugin, which will likely fail and result
+		// in an obscure message.
+		return nil, err
+	}
+	// Failing the above, try loading it as a Go plugin.
+	c, err := l.loadGoPlugin(resId)
+	if err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+// registry is a means to avoid trying to load the same .so file
+// into memory more than once, which results in an error.
+// Each test makes its own loader, and tries to load its own plugins,
+// but the loaded .so files are in shared memory, so one will get
+// "this plugin already loaded" errors if the registry is maintained
+// as a Loader instance variable.  So make it a package variable.
+var registry = make(map[string]resmap.Configurable)
+
+func (l *Loader) loadGoPlugin(id resid.ResId) (resmap.Configurable, error) {
+	regId := relativePluginPath(id)
+	if c, ok := registry[regId]; ok {
+		return copyPlugin(c), nil
+	}
+	absPath := l.absolutePluginPath(id) + ".so"
+	if !utils.FileExists(absPath) {
+		return nil, fmt.Errorf(
+			"expected file with Go object code at: %s", absPath)
+	}
+	log.Printf("Attempting plugin load from '%s'", absPath)
+	p, err := plugin.Open(absPath)
+	if err != nil {
+		return nil, errors.Wrapf(err, "plugin %s fails to load", absPath)
+	}
+	symbol, err := p.Lookup(konfig.PluginSymbol)
+	if err != nil {
+		return nil, errors.Wrapf(
+			err, "plugin %s doesn't have symbol %s",
+			regId, konfig.PluginSymbol)
+	}
+	c, ok := symbol.(resmap.Configurable)
+	if !ok {
+		return nil, fmt.Errorf("plugin '%s' not configurable", regId)
+	}
+	registry[regId] = c
+	return copyPlugin(c), nil
+}
+
+func copyPlugin(c resmap.Configurable) resmap.Configurable {
+	indirect := reflect.Indirect(reflect.ValueOf(c))
+	newIndirect := reflect.New(indirect.Type())
+	newIndirect.Elem().Set(reflect.ValueOf(indirect.Interface()))
+	newNamed := newIndirect.Interface()
+	return newNamed.(resmap.Configurable)
+}