tools: Improve proto annotation documentation

tools/proto-annotations/main.go

@@ -15,129 +15,15 @@
 package main
 
 import (
-	"bytes"
-	"flag"
 	"fmt"
-	"io"
 	"os"
-	"sort"
 
-	"github.com/coreos/go-semver/semver"
-	"go.etcd.io/etcd/server/v3/storage/wal"
-	"google.golang.org/protobuf/reflect/protoreflect"
-	"google.golang.org/protobuf/reflect/protoregistry"
-)
-
-const (
-	EtcdVersionAnnotation = "etcd_version"
+	"go.etcd.io/etcd/v3/tools/proto-annotations/cmd"
 )
 
 func main() {
-	annotation := flag.String("annotation", "", "Specify what proto annotation to read. Options: etcd_version")
-	flag.Parse()
-	var errs []error
-	switch *annotation {
-	case EtcdVersionAnnotation:
-		errs = handleEtcdVersion()
-	case "":
-		fmt.Fprintf(os.Stderr, "Please provide --annotation flag")
-		os.Exit(1)
-	default:
-		fmt.Fprintf(os.Stderr, "Unknown annotation %q. Options: etcd_version", *annotation)
+	if err := cmd.RootCmd().Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}
-	if len(errs) != 0 {
-		for _, err := range errs {
-			fmt.Fprintln(os.Stderr, err)
-		}
-		os.Exit(1)
-	}
-	os.Exit(0)
-}
-
-func handleEtcdVersion() (errs []error) {
-	annotations, err := allEtcdVersionAnnotations()
-	if err != nil {
-		errs = append(errs, err)
-		return errs
-	}
-	sort.Slice(annotations, func(i, j int) bool {
-		return annotations[i].fullName < annotations[j].fullName
-	})
-	output := &bytes.Buffer{}
-	for _, a := range annotations {
-		newErrs := a.Validate()
-		if len(newErrs) == 0 {
-			err := a.PrintLine(output)
-			if err != nil {
-				errs = append(errs, err)
-				return errs
-			}
-		}
-		errs = append(errs, newErrs...)
-	}
-	if len(errs) == 0 {
-		fmt.Print(output)
-	}
-	return errs
-}
-
-func allEtcdVersionAnnotations() (annotations []etcdVersionAnnotation, err error) {
-	var fileAnnotations []etcdVersionAnnotation
-	protoregistry.GlobalFiles.RangeFiles(func(file protoreflect.FileDescriptor) bool {
-		switch string(file.Package()) {
-		// Skip external packages that are not expected to have etcd version annotation.
-		case "io.prometheus.client", "grpc.binarylog.v1", "google.protobuf", "google.rpc", "google.api":
-			return true
-		}
-		fileAnnotations, err = fileEtcdVersionAnnotations(file)
-		if err != nil {
-			return false
-		}
-		annotations = append(annotations, fileAnnotations...)
-		return true
-	})
-	return annotations, err
-}
-
-func fileEtcdVersionAnnotations(file protoreflect.FileDescriptor) (annotations []etcdVersionAnnotation, err error) {
-	err = wal.VisitFileDescriptor(file, func(path protoreflect.FullName, ver *semver.Version) error {
-		a := etcdVersionAnnotation{fullName: path, version: ver}
-		annotations = append(annotations, a)
-		return nil
-	})
-	return annotations, err
-}
-
-type etcdVersionAnnotation struct {
-	fullName protoreflect.FullName
-	version  *semver.Version
-}
-
-func (a etcdVersionAnnotation) Validate() (errs []error) {
-	if a.version == nil {
-		return nil
-	}
-	if a.version.Major == 0 {
-		errs = append(errs, fmt.Errorf("%s: etcd_version major version should not be zero", a.fullName))
-	}
-	if a.version.Patch != 0 {
-		errs = append(errs, fmt.Errorf("%s: etcd_version patch version should be zero", a.fullName))
-	}
-	if a.version.PreRelease != "" {
-		errs = append(errs, fmt.Errorf("%s: etcd_version should not be prerelease", a.fullName))
-	}
-	if a.version.Metadata != "" {
-		errs = append(errs, fmt.Errorf("%s: etcd_version should not have metadata", a.fullName))
-	}
-	return errs
-}
-
-func (a etcdVersionAnnotation) PrintLine(out io.Writer) error {
-	if a.version == nil {
-		_, err := fmt.Fprintf(out, "%s: \"\"\n", a.fullName)
-		return err
-	}
-	_, err := fmt.Fprintf(out, "%s: \"%d.%d\"\n", a.fullName, a.version.Major, a.version.Minor)
-	return err
 }