move files into internal

cmd/pluginator/internal/builtinplugin/builtinplugin.go

@@ -0,0 +1,176 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package builtinplugin
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"sigs.k8s.io/kustomize/api/konfig"
+	"sigs.k8s.io/kustomize/api/provenance"
+)
+
+//go:generate stringer -type=pluginType
+type pluginType int
+
+const packageForGeneratedCode = "builtins"
+
+const (
+	unknown pluginType = iota
+	Transformer
+	Generator
+)
+
+// ConvertToBuiltInPlugin converts the input plugin file to
+// kustomize builtin plugin and writes it to proper directory
+func ConvertToBuiltInPlugin() error {
+	root, err := inputFileRoot()
+	if err != nil {
+		return err
+	}
+	file, err := os.Open(root + ".go")
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	scanner := bufio.NewScanner(file)
+	err = readToPackageMain(scanner, file.Name())
+	if err != nil {
+		return err
+	}
+
+	w, err := newWriter(root)
+	if err != nil {
+		return err
+	}
+	defer w.close()
+
+	// This particular phrasing is required.
+	w.write(
+		fmt.Sprintf(
+			"// Code generated by pluginator on %s; DO NOT EDIT.",
+			root))
+	w.write(
+		fmt.Sprintf(
+			"// pluginator %s\n", provenance.GetProvenance().Short()))
+	w.write("\n")
+	w.write("package " + packageForGeneratedCode)
+
+	pType := unknown
+
+	for scanner.Scan() {
+		l := scanner.Text()
+		if strings.HasPrefix(l, "//go:generate") {
+			continue
+		}
+		if strings.HasPrefix(l, "//noinspection") {
+			continue
+		}
+		if l == "var "+konfig.PluginSymbol+" plugin" {
+			continue
+		}
+		if strings.Contains(l, " Transform(") {
+			if pType != unknown {
+				return fmt.Errorf("unexpected Transform(")
+			}
+			pType = Transformer
+		} else if strings.Contains(l, " Generate(") {
+			if pType != unknown {
+				return fmt.Errorf("unexpected Generate(")
+			}
+			pType = Generator
+		}
+		w.write(l)
+	}
+	if err := scanner.Err(); err != nil {
+		return err
+	}
+	w.write("")
+	w.write("func New" + root + "Plugin() resmap." + pType.String() + "Plugin {")
+	w.write("  return &" + root + "Plugin{}")
+	w.write("}")
+
+	return nil
+}
+
+func inputFileRoot() (string, error) {
+	n := os.Getenv("GOFILE")
+	if !strings.HasSuffix(n, ".go") {
+		return "", fmt.Errorf("%+v, expecting .go suffix on %s", provenance.GetProvenance(), n)
+	}
+	return n[:len(n)-len(".go")], nil
+}
+
+func readToPackageMain(s *bufio.Scanner, f string) error {
+	gotMain := false
+	for !gotMain && s.Scan() {
+		gotMain = strings.HasPrefix(s.Text(), "package main")
+	}
+	if !gotMain {
+		return fmt.Errorf("%s missing package main", f)
+	}
+	return nil
+}
+
+type writer struct {
+	root string
+	f    *os.File
+}
+
+func newWriter(r string) (*writer, error) {
+	n := makeOutputFileName(r)
+	f, err := os.Create(n)
+	if err != nil {
+		return nil, fmt.Errorf("unable to create `%s`; %v", n, err)
+	}
+	return &writer{root: r, f: f}, nil
+}
+
+// Assume that this command is running with a $PWD of
+//   $HOME/kustomize/plugin/builtin/secretGenerator
+// (for example).  Then we want to write to
+//   $HOME/kustomize/api/builtins
+func makeOutputFileName(root string) string {
+	return filepath.Join(
+		"..", "..", "..", "api", packageForGeneratedCode, root+".go")
+}
+
+func (w *writer) close() {
+	// Do this for debugging.
+	// fmt.Println("Generated " + makeOutputFileName(w.root))
+	w.f.Close()
+}
+
+func (w *writer) write(line string) {
+	_, err := w.f.WriteString(w.filter(line) + "\n")
+	if err != nil {
+		fmt.Printf("Trouble writing: %s", line)
+		fmt.Printf("Error: %s", err)
+		os.Exit(1)
+	}
+}
+
+func (w *writer) filter(in string) string {
+	if ok, newer := w.replace(in, "type plugin struct"); ok {
+		return newer
+	}
+	if ok, newer := w.replace(in, "*plugin)"); ok {
+		return newer
+	}
+	return in
+}
+
+// replace 'plugin' with 'FooPlugin' in context
+// sensitive manner.
+func (w *writer) replace(in, target string) (bool, string) {
+	if !strings.Contains(in, target) {
+		return false, ""
+	}
+	newer := strings.Replace(
+		target, "plugin", w.root+"Plugin", 1)
+	return true, strings.Replace(in, target, newer, 1)
+}