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
+}

cmd/k8scopy/internal/modulespec.go

@@ -0,0 +1,37 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package internal
+
+import (
+	"io/ioutil"
+
+	"sigs.k8s.io/yaml"
+)
+
+type ModuleSpec struct {
+	Module   string        `json:"module,omitempty" yaml:"module,omitempty"`
+	Version  string        `json:"version,omitempty" yaml:"version,omitempty"`
+	Packages []PackageSpec `json:"packages,omitempty" yaml:"packages,omitempty"`
+}
+
+func (s ModuleSpec) Name() string {
+	return s.Module + "@" + s.Version
+}
+
+type PackageSpec struct {
+	Name  string   `json:"name,omitempty" yaml:"name,omitempty"`
+	Files []string `json:"files,omitempty" yaml:"files,omitempty"`
+}
+
+func ReadSpec(fileName string) *ModuleSpec {
+	bytes, err := ioutil.ReadFile(fileName)
+	if err != nil {
+		panic(err)
+	}
+	var spec ModuleSpec
+	if err = yaml.Unmarshal(bytes, &spec); err != nil {
+		panic(err)
+	}
+	return &spec
+}

cmd/k8scopy/internal/modulespec_test.go

@@ -0,0 +1,65 @@
+// Copyright 2021 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package internal_test
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	. "sigs.k8s.io/kustomize/cmd/k8scopy/internal"
+)
+
+var data = []byte(`module: k8s.io/apimachinery
+version: v0.17.0
+packages:
+- name: pkg/labels
+  files:
+  - labels.go
+  - selector.go
+  - zz_generated.deepcopy.go
+- name: pkg/selection
+  files:
+  - operator.go
+- name: pkg/util/sets
+  files:
+  - empty.go
+  - string.go
+- name: pkg/util/errors
+  files:
+  - errors.go
+- name: pkg/util/validation
+  files:
+  - validation.go
+- name: pkg/util/validation/field
+  files:
+  - errors.go
+  - path.go
+`)
+
+func TestReadSpec(t *testing.T) {
+	fn := writeFile(t, data)
+	defer os.Remove(fn)
+	x := ReadSpec(fn)
+	assert.Equal(t, "k8s.io/apimachinery@v0.17.0", x.Name())
+	assert.Equal(t, 6, len(x.Packages))
+	assert.Equal(t, "pkg/util/validation/field", x.Packages[5].Name)
+	assert.Equal(t, "path.go", x.Packages[5].Files[1])
+}
+
+// Write content to temp file, returning file name.
+func writeFile(t *testing.T, content []byte) string {
+	f, err := ioutil.TempFile("", "testjunk")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err = f.Write(content); err != nil {
+		t.Fatal(err)
+	}
+	if err := f.Close(); err != nil {
+		t.Fatal(err)
+	}
+	return f.Name()
+}

cmd/k8scopy/internal/utils.go

@@ -0,0 +1,32 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package internal
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"os/exec"
+	"strings"
+)
+
+func RunNoOutputCommand(n string, args ...string) {
+	o := RunGetOutputCommand(n, args...)
+	if len(o) > 0 {
+		log.Fatalf("unexpected output: %q", o)
+	}
+}
+
+func RunGetOutputCommand(n string, args ...string) string {
+	cmd := exec.Command(n, args...)
+	var outBuf bytes.Buffer
+	cmd.Stdout = &outBuf
+	var errBuf bytes.Buffer
+	cmd.Stderr = &errBuf
+	if err := cmd.Run(); err != nil {
+		fmt.Printf("err: %q\n", errBuf.String())
+		log.Fatal(err)
+	}
+	return strings.TrimSpace(outBuf.String())
+}

cmd/k8scopy/internal/writer.go

@@ -0,0 +1,40 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package internal
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+)
+
+type writer struct {
+	root string
+	f    *os.File
+}
+
+func newWriter(toDir, name string) (*writer, error) {
+	if err := os.MkdirAll(toDir, 0755); err != nil {
+		log.Printf("unable to create directory: %s", toDir)
+		return nil, err
+	}
+	n := filepath.Join(toDir, name)
+	f, err := os.Create(n)
+	if err != nil {
+		return nil, fmt.Errorf("unable to create `%s`; %v", n, err)
+	}
+	return &writer{root: toDir, f: f}, nil
+}
+
+func (w *writer) close() {
+	w.f.Close()
+}
+
+func (w *writer) write(line string) {
+	if _, err := w.f.WriteString(line + "\n"); err != nil {
+		log.Printf("Trouble writing: %s", line)
+		log.Fatalf("Error: %s", err)
+	}
+}