Remove remaining plugins packages from external API.

api/internal/plugins/execplugin/execplugin.go

@@ -0,0 +1,270 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package execplugin
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+
+	"github.com/pkg/errors"
+	"sigs.k8s.io/kustomize/api/resid"
+	"sigs.k8s.io/kustomize/api/resmap"
+	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/yaml"
+)
+
+const (
+	idAnnotation        = "kustomize.config.k8s.io/id"
+	HashAnnotation      = "kustomize.config.k8s.io/needs-hash"
+	BehaviorAnnotation  = "kustomize.config.k8s.io/behavior"
+	tmpConfigFilePrefix = "kust-plugin-config-"
+)
+
+// ExecPlugin record the name and args of an executable
+// It triggers the executable generator and transformer
+type ExecPlugin struct {
+	// absolute path of the executable
+	path string
+
+	// Optional command line arguments to the executable
+	// pulled from specially named fields in cfg.
+	// This is for executables that don't want to parse YAML.
+	args []string
+
+	// Plugin configuration data.
+	cfg []byte
+
+	// PluginHelpers
+	h *resmap.PluginHelpers
+}
+
+func NewExecPlugin(p string) *ExecPlugin {
+	return &ExecPlugin{path: p}
+}
+
+func (p *ExecPlugin) ErrIfNotExecutable() error {
+	f, err := os.Stat(p.path)
+	if err != nil {
+		return err
+	}
+	if f.Mode()&0111 == 0000 {
+		return fmt.Errorf("unexecutable plugin at: %s", p.path)
+	}
+	return nil
+}
+
+func (p *ExecPlugin) Path() string {
+	return p.path
+}
+
+func (p *ExecPlugin) Args() []string {
+	return p.args
+}
+
+func (p *ExecPlugin) Cfg() []byte {
+	return p.cfg
+}
+
+func (p *ExecPlugin) Config(h *resmap.PluginHelpers, config []byte) error {
+	p.h = h
+	p.cfg = config
+	return p.processOptionalArgsFields()
+}
+
+type argsConfig struct {
+	ArgsOneLiner string `json:"argsOneLiner,omitempty" yaml:"argsOneLiner,omitempty"`
+	ArgsFromFile string `json:"argsFromFile,omitempty" yaml:"argsFromFile,omitempty"`
+}
+
+func (p *ExecPlugin) processOptionalArgsFields() error {
+	var c argsConfig
+	yaml.Unmarshal(p.cfg, &c)
+	if c.ArgsOneLiner != "" {
+		p.args = strings.Split(c.ArgsOneLiner, " ")
+	}
+	if c.ArgsFromFile != "" {
+		content, err := p.h.Loader().Load(c.ArgsFromFile)
+		if err != nil {
+			return err
+		}
+		for _, x := range strings.Split(string(content), "\n") {
+			x := strings.TrimLeft(x, " ")
+			if x != "" {
+				p.args = append(p.args, x)
+			}
+		}
+	}
+	return nil
+}
+
+func (p *ExecPlugin) Generate() (resmap.ResMap, error) {
+	output, err := p.invokePlugin(nil)
+	if err != nil {
+		return nil, err
+	}
+	rm, err := p.h.ResmapFactory().NewResMapFromBytes(output)
+	if err != nil {
+		return nil, err
+	}
+	return p.UpdateResourceOptions(rm)
+}
+
+func (p *ExecPlugin) Transform(rm resmap.ResMap) error {
+	// add ResIds as annotations to all objects so that we can add them back
+	inputRM, err := p.getResMapWithIdAnnotation(rm)
+	if err != nil {
+		return err
+	}
+
+	// encode the ResMap so it can be fed to the plugin
+	resources, err := inputRM.AsYaml()
+	if err != nil {
+		return err
+	}
+
+	// invoke the plugin with resources as the input
+	output, err := p.invokePlugin(resources)
+	if err != nil {
+		return fmt.Errorf("%v %s", err, string(output))
+	}
+
+	// update the original ResMap based on the output
+	return p.updateResMapValues(output, rm)
+}
+
+// invokePlugin writes plugin config to a temp file, then
+// passes the full temp file path as the first arg to a process
+// running the plugin binary.  Process output is returned.
+func (p *ExecPlugin) invokePlugin(input []byte) ([]byte, error) {
+	f, err := ioutil.TempFile("", tmpConfigFilePrefix)
+	if err != nil {
+		return nil, errors.Wrap(
+			err, "creating tmp plugin config file")
+	}
+	_, err = f.Write(p.cfg)
+	if err != nil {
+		return nil, errors.Wrap(
+			err, "writing plugin config to "+f.Name())
+	}
+	err = f.Close()
+	if err != nil {
+		return nil, errors.Wrap(
+			err, "closing plugin config file "+f.Name())
+	}
+	cmd := exec.Command(
+		p.path, append([]string{f.Name()}, p.args...)...)
+	cmd.Env = p.getEnv()
+	cmd.Stdin = bytes.NewReader(input)
+	cmd.Stderr = os.Stderr
+	if _, err := os.Stat(p.h.Loader().Root()); err == nil {
+		cmd.Dir = p.h.Loader().Root()
+	}
+	result, err := cmd.Output()
+	if err != nil {
+		return nil, errors.Wrapf(
+			err, "failure in plugin configured via %s; %v",
+			f.Name(), err.Error())
+	}
+	return result, os.Remove(f.Name())
+}
+
+func (p *ExecPlugin) getEnv() []string {
+	env := os.Environ()
+	env = append(env,
+		"KUSTOMIZE_PLUGIN_CONFIG_STRING="+string(p.cfg),
+		"KUSTOMIZE_PLUGIN_CONFIG_ROOT="+p.h.Loader().Root())
+	return env
+}
+
+// Returns a new copy of the given ResMap with the ResIds annotated in each Resource
+func (p *ExecPlugin) getResMapWithIdAnnotation(rm resmap.ResMap) (resmap.ResMap, error) {
+	inputRM := rm.DeepCopy()
+	for _, r := range inputRM.Resources() {
+		idString, err := yaml.Marshal(r.CurId())
+		if err != nil {
+			return nil, err
+		}
+		annotations := r.GetAnnotations()
+		if annotations == nil {
+			annotations = make(map[string]string)
+		}
+		annotations[idAnnotation] = string(idString)
+		r.SetAnnotations(annotations)
+	}
+	return inputRM, nil
+}
+
+// updateResMapValues updates the Resource value in the given ResMap
+// with the emitted Resource values in output.
+func (p *ExecPlugin) updateResMapValues(output []byte, rm resmap.ResMap) error {
+	outputRM, err := p.h.ResmapFactory().NewResMapFromBytes(output)
+	if err != nil {
+		return err
+	}
+	for _, r := range outputRM.Resources() {
+		// for each emitted Resource, find the matching Resource in the original ResMap
+		// using its id
+		annotations := r.GetAnnotations()
+		idString, ok := annotations[idAnnotation]
+		if !ok {
+			return fmt.Errorf("the transformer %s should not remove annotation %s",
+				p.path, idAnnotation)
+		}
+		id := resid.ResId{}
+		err := yaml.Unmarshal([]byte(idString), &id)
+		if err != nil {
+			return err
+		}
+		res, err := rm.GetByCurrentId(id)
+		if err != nil {
+			return fmt.Errorf("unable to find unique match to %s", id.String())
+		}
+		// remove the annotation set by Kustomize to track the resource
+		delete(annotations, idAnnotation)
+		if len(annotations) == 0 {
+			annotations = nil
+		}
+		r.SetAnnotations(annotations)
+
+		// update the ResMap resource value with the transformed object
+		res.Kunstructured = r.Kunstructured
+	}
+	return nil
+}
+
+// updateResourceOptions updates the generator options for each resource in the
+// given ResMap based on plugin provided annotations.
+func (p *ExecPlugin) UpdateResourceOptions(rm resmap.ResMap) (resmap.ResMap, error) {
+	for _, r := range rm.Resources() {
+		// Disable name hashing by default and require plugin to explicitly
+		// request it for each resource.
+		annotations := r.GetAnnotations()
+		behavior := annotations[BehaviorAnnotation]
+		var needsHash bool
+		if val, ok := annotations[HashAnnotation]; ok {
+			b, err := strconv.ParseBool(val)
+			if err != nil {
+				return nil, fmt.Errorf(
+					"the annotation %q contains an invalid value (%q)",
+					HashAnnotation, val)
+			}
+			needsHash = b
+		}
+		delete(annotations, HashAnnotation)
+		delete(annotations, BehaviorAnnotation)
+		if len(annotations) == 0 {
+			annotations = nil
+		}
+		r.SetAnnotations(annotations)
+		r.SetOptions(types.NewGenArgs(
+			&types.GeneratorArgs{Behavior: behavior},
+			&types.GeneratorOptions{DisableNameSuffixHash: !needsHash}))
+	}
+	return rm, nil
+}