server: fix unexported-return using interfaces

Signed-off-by: adeyemi <[email protected]>

Author: aladesawe

server/auth/store.go

@@ -938,7 +938,7 @@ func (as *authStore) IsAuthEnabled() bool {
 }
 
 // NewAuthStore creates a new AuthStore.
-func NewAuthStore(lg *zap.Logger, be AuthBackend, tp TokenProvider, bcryptCost int) *authStore {
+func NewAuthStore(lg *zap.Logger, be AuthBackend, tp TokenProvider, bcryptCost int) AuthStore {
 	if lg == nil {
 		lg = zap.NewNop()
 	}

server/auth/store_test.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"go.uber.org/zap/zaptest"
 	"golang.org/x/crypto/bcrypt"
 	"google.golang.org/grpc/metadata"
@@ -116,12 +117,14 @@ func setupAuthStore(t *testing.T) (store *authStore, teardownfunc func(t *testin
 
 	// The UserAdd function cannot generate old etcd version user data (user's option is nil)
 	// add special users through the underlying interface
-	addUserWithNoOption(as)
+	asImpl, ok := as.(*authStore)
+	require.Truef(t, ok, "addUserWithNoOption: needs an AuthStore implementation")
+	addUserWithNoOption(asImpl)
 
 	tearDown := func(_ *testing.T) {
 		as.Close()
 	}
-	return as, tearDown
+	return asImpl, tearDown
 }
 
 func addUserWithNoOption(as *authStore) {
@@ -136,7 +139,7 @@ func addUserWithNoOption(as *authStore) {
 	as.refreshRangePermCache(tx)
 }
 
-func enableAuthAndCreateRoot(as *authStore) error {
+func enableAuthAndCreateRoot(as AuthStore) error {
 	_, err := as.UserAdd(&pb.AuthUserAddRequest{Name: "root", HashedPassword: encodePassword("root"), Options: &authpb.UserAddOptions{NoPassword: false}})
 	if err != nil {
 		return err

server/etcdserver/adapters.go

@@ -33,7 +33,7 @@ type serverVersionAdapter struct {
 	*EtcdServer
 }
 
-func NewServerVersionAdapter(s *EtcdServer) *serverVersionAdapter {
+func NewServerVersionAdapter(s *EtcdServer) serverversion.Server {
 	return &serverVersionAdapter{
 		EtcdServer: s,
 	}

server/storage/mvcc/kvstore.go

@@ -82,6 +82,7 @@ type store struct {
 
 // NewStore returns a new store. It is useful to create a store inside
 // mvcc pkg. It should only be used for testing externally.
+// revive:disable-next-line:unexported-return this is used internally in the mvcc pkg
 func NewStore(lg *zap.Logger, b backend.Backend, le lease.Lessor, cfg StoreConfig) *store {
 	if lg == nil {
 		lg = zap.NewNop()

server/storage/mvcc/watchable_store.go

@@ -76,7 +76,7 @@ var _ WatchableKV = (*watchableStore)(nil)
 // cancel operations.
 type cancelFunc func()
 
-func New(lg *zap.Logger, b backend.Backend, le lease.Lessor, cfg StoreConfig) *watchableStore {
+func New(lg *zap.Logger, b backend.Backend, le lease.Lessor, cfg StoreConfig) WatchableKV {
 	s := newWatchableStore(lg, b, le, cfg)
 	s.wg.Add(2)
 	go s.syncWatchersLoop()

server/storage/mvcc/watchable_store_test.go

@@ -44,7 +44,7 @@ func TestWatch(t *testing.T) {
 	defer w.Close()
 
 	w.Watch(0, testKey, nil, 0)
-	if !s.synced.contains(string(testKey)) {
+	if !s.(*watchableStore).synced.contains(string(testKey)) {
 		// the key must have had an entry in synced
 		t.Errorf("existence = false, want true")
 	}
@@ -67,7 +67,7 @@ func TestNewWatcherCancel(t *testing.T) {
 		t.Error(err)
 	}
 
-	if s.synced.contains(string(testKey)) {
+	if s.(*watchableStore).synced.contains(string(testKey)) {
 		// the key shoud have been deleted
 		t.Errorf("existence = true, want false")
 	}
@@ -340,7 +340,9 @@ func TestWatchNoEventLossOnCompact(t *testing.T) {
 		require.NoError(t, err)
 	}
 	// fill up w.Chan() with 1 buf via 2 compacted watch response
-	s.syncWatchers([]mvccpb.Event{})
+	sImpl, ok := s.(*watchableStore)
+	require.Truef(t, ok, "TestWatchNoEventLossOnCompact: needs a WatchableKV implementation")
+	sImpl.syncWatchers([]mvccpb.Event{})
 
 	for len(watchers) > 0 {
 		resp := <-w.Chan()
@@ -355,7 +357,7 @@ func TestWatchNoEventLossOnCompact(t *testing.T) {
 			require.Equalf(t, nextRev, ev.Kv.ModRevision, "got event revision %d but want %d for watcher with watch ID %d", ev.Kv.ModRevision, nextRev, resp.WatchID)
 			nextRev++
 		}
-		if nextRev == s.rev()+1 {
+		if nextRev == sImpl.rev()+1 {
 			delete(watchers, resp.WatchID)
 		}
 	}
@@ -566,10 +568,13 @@ func TestWatchBatchUnsynced(t *testing.T) {
 			}
 			assert.Equal(t, tc.expectRevisionBatches, revisionBatches)
 
-			s.store.revMu.Lock()
-			defer s.store.revMu.Unlock()
-			assert.Equal(t, 1, s.synced.size())
-			assert.Equal(t, 0, s.unsynced.size())
+			sImpl, ok := s.(*watchableStore)
+			require.Truef(t, ok, "TestWatchBatchUnsynced: needs a WatchableKV implementation")
+
+			sImpl.store.revMu.Lock()
+			defer sImpl.store.revMu.Unlock()
+			assert.Equal(t, 1, sImpl.synced.size())
+			assert.Equal(t, 0, sImpl.unsynced.size())
 		})
 	}
 }

server/storage/schema/auth.go

@@ -40,7 +40,7 @@ type authBackend struct {
 
 var _ auth.AuthBackend = (*authBackend)(nil)
 
-func NewAuthBackend(lg *zap.Logger, be backend.Backend) *authBackend {
+func NewAuthBackend(lg *zap.Logger, be backend.Backend) auth.AuthBackend {
 	return &authBackend{
 		be: be,
 		lg: lg,

server/storage/schema/schema.go

@@ -73,7 +73,10 @@ func UnsafeMigrate(lg *zap.Logger, tx backend.UnsafeReadWriter, w WALVersion, ta
 	if target.LessThan(current) {
 		minVersion := w.MinimalEtcdVersion()
 		if minVersion != nil && target.LessThan(*minVersion) {
-			return fmt.Errorf("cannot downgrade storage, WAL contains newer entries")
+			// Occasionally we may see this error during downgrade test due to ClusterVersionSet,
+			// which is harmless. Please read https://github.com/etcd-io/etcd/pull/13405#discussion_r1890378185.
+			return fmt.Errorf("cannot downgrade storage, WAL contains newer entries, as the target version (%s) is lower than the version (%s) detected from WAL logs",
+				target.String(), minVersion.String())
 		}
 	}
 	return plan.unsafeExecute(lg, tx)