Migrate WALVersion to fix unexported-return of walVersion

etcdutl/etcdutl/migrate_command.go

@@ -97,7 +97,7 @@ func (o *migrateOptions) Config() (*migrateConfig, error) {
 type migrateConfig struct {
 	lg            *zap.Logger
 	targetVersion *semver.Version
-	walVersion    schema.WALVersion
+	walVersion    wal.Version
 	dataDir       string
 	force         bool
 }

server/storage/schema/schema.go

@@ -22,6 +22,7 @@ import (
 
 	"go.etcd.io/etcd/api/v3/version"
 	"go.etcd.io/etcd/server/v3/storage/backend"
+	"go.etcd.io/etcd/server/v3/storage/wal"
 )
 
 // Validate checks provided backend to confirm that schema used is supported.
@@ -47,21 +48,16 @@ func localBinaryVersion() semver.Version {
 	return semver.Version{Major: v.Major, Minor: v.Minor}
 }
 
-type WALVersion interface {
-	// MinimalEtcdVersion returns minimal etcd version able to interpret WAL log.
-	MinimalEtcdVersion() *semver.Version
-}
-
 // Migrate updates storage schema to provided target version.
 // Downgrading requires that provided WAL doesn't contain unsupported entries.
-func Migrate(lg *zap.Logger, tx backend.BatchTx, w WALVersion, target semver.Version) error {
+func Migrate(lg *zap.Logger, tx backend.BatchTx, w wal.Version, target semver.Version) error {
 	tx.LockOutsideApply()
 	defer tx.Unlock()
 	return UnsafeMigrate(lg, tx, w, target)
 }
 
 // UnsafeMigrate is non thread-safe version of Migrate.
-func UnsafeMigrate(lg *zap.Logger, tx backend.UnsafeReadWriter, w WALVersion, target semver.Version) error {
+func UnsafeMigrate(lg *zap.Logger, tx backend.UnsafeReadWriter, w wal.Version, target semver.Version) error {
 	current, err := UnsafeDetectSchemaVersion(lg, tx)
 	if err != nil {
 		return fmt.Errorf("cannot detect storage schema version: %w", err)

server/storage/wal/version.go

@@ -29,9 +29,15 @@ import (
 	"go.etcd.io/raft/v3/raftpb"
 )
 
+// Version defines the wal version interface.
+type Version interface {
+	// MinimalEtcdVersion returns minimal etcd version able to interpret WAL log.
+	MinimalEtcdVersion() *semver.Version
+}
+
 // ReadWALVersion reads remaining entries from opened WAL and returns struct
 // that implements schema.WAL interface.
-func ReadWALVersion(w *WAL) (*walVersion, error) {
+func ReadWALVersion(w *WAL) (Version, error) {
 	_, _, ents, err := w.ReadAll()
 	if err != nil {
 		return nil, err