Move the k8s code generator.

cmd/k8scopy/internal/copier.go

@@ -0,0 +1,111 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package internal
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	sigsK8sIo = "sigs.k8s.io"
+)
+
+type Copier struct {
+	spec       *ModuleSpec
+	goModCache string
+	topPackage string
+	srcDir     string
+	pgmName    string
+}
+
+func (c Copier) replacementPath() string {
+	return filepath.Join(c.topPackage, c.subPath())
+}
+
+func (c Copier) subPath() string {
+	return filepath.Join("internal", c.pgmName)
+}
+
+func (c Copier) print() {
+	fmt.Printf("   apiMachineryModule: %s\n", c.spec.Module)
+	fmt.Printf("      replacementPath: %s\n", c.replacementPath())
+	fmt.Printf("           goModCache: %s\n", c.goModCache)
+	fmt.Printf("           topPackage: %s\n", c.topPackage)
+	fmt.Printf("              subPath: %s\n", c.subPath())
+	fmt.Printf("               srcDir: %s\n", c.srcDir)
+	fmt.Printf("  apiMachineryModSpec: %s\n", c.spec.Name())
+	fmt.Printf("              pgmName: %s\n", c.pgmName)
+	fmt.Printf("                  pwd: %s\n", os.Getenv("PWD"))
+}
+
+func NewCopier(s *ModuleSpec) Copier {
+	tmp := Copier{
+		spec:       s,
+		pgmName:    os.Getenv("GOPACKAGE"),
+		goModCache: RunGetOutputCommand("go", "env", "GOMODCACHE"),
+	}
+	goMod := RunGetOutputCommand("go", "env", "GOMOD")
+	topPackage := filepath.Join(goMod[:len(goMod)-len("go.mod")-1], "yaml")
+	k := strings.Index(topPackage, sigsK8sIo)
+	if k < 1 {
+		log.Fatalf("cannot find %s in %s", sigsK8sIo, topPackage)
+	}
+	tmp.srcDir = topPackage[:k-1]
+	tmp.topPackage = topPackage[k:]
+	return tmp
+}
+
+func (c Copier) CopyFile(dir, name string) error {
+	inFile, err := os.Open(
+		filepath.Join(c.goModCache, c.spec.Name(), dir, name))
+	if err != nil {
+		return err
+	}
+	defer inFile.Close()
+	scanner := bufio.NewScanner(inFile)
+
+	w, err := newWriter(dir, name)
+	if err != nil {
+		return err
+	}
+	defer w.close()
+
+	w.write(
+		fmt.Sprintf(
+			// This particular phrasing is required.
+			"// Code generated by %s/generator from %s; DO NOT EDIT.",
+			c.pgmName, c.spec.Name()))
+	w.write(
+		fmt.Sprintf(
+			"// Copied from %s\n",
+			filepath.Join(c.spec.Name(), dir, name)))
+
+	for scanner.Scan() {
+		l := scanner.Text()
+		// Disallow recursive generation.
+		if strings.HasPrefix(l, "//go:generate") {
+			continue
+		}
+		// Don't want it to appear double generated.
+		if strings.HasPrefix(l, "// Code generated") {
+			continue
+		}
+		// Fix self-imports.
+		l = strings.Replace(l, c.spec.Module, c.replacementPath(), 1)
+		// Replace klog with generic log (eschewing k8s.io entirely).
+		l = strings.Replace(l, "\"k8s.io/klog\"", "\"log\"", 1)
+		l = strings.Replace(l, "klog.V(10).Infof(", "log.Printf(", 1)
+		w.write(l)
+	}
+	if err := scanner.Err(); err != nil {
+		return err
+	}
+	w.write("")
+	return nil
+}