From cc7875bd3638224fae91a1103ec27bedaa42dc33 Mon Sep 17 00:00:00 2001
From: Wei Fu <fuweid89@gmail.com>
Date: Sat, 28 Dec 2024 22:12:28 +0000
Subject: [PATCH] *: support custom content check offline in v2store

Part of #18993

Signed-off-by: Wei Fu <fuweid89@gmail.com>
---
 etcdutl/ctl.go                        |   1 +
 etcdutl/etcdutl/check_command.go      | 112 ++++++++++++++++++++++++++
 tests/e2e/v2store_deprecation_test.go |  19 +++++
 3 files changed, 132 insertions(+)
 create mode 100644 etcdutl/etcdutl/check_command.go

diff --git a/etcdutl/ctl.go b/etcdutl/ctl.go
index a044547c63c6..dbdc5cc7810d 100644
--- a/etcdutl/ctl.go
+++ b/etcdutl/ctl.go
@@ -41,6 +41,7 @@ func init() {
 		etcdutl.NewDefragCommand(),
 		etcdutl.NewSnapshotCommand(),
 		etcdutl.NewVersionCommand(),
+		etcdutl.NewCheckCommand(),
 	)
 }
 
diff --git a/etcdutl/etcdutl/check_command.go b/etcdutl/etcdutl/check_command.go
new file mode 100644
index 000000000000..e7f6992e136e
--- /dev/null
+++ b/etcdutl/etcdutl/check_command.go
@@ -0,0 +1,112 @@
+// Copyright 2024 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdutl
+
+import (
+	"errors"
+	"fmt"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+
+	"go.etcd.io/etcd/pkg/v3/cobrautl"
+	"go.etcd.io/etcd/server/v3/etcdserver/api/membership"
+	"go.etcd.io/etcd/server/v3/etcdserver/api/snap"
+	"go.etcd.io/etcd/server/v3/etcdserver/api/v2store"
+	"go.etcd.io/etcd/server/v3/wal"
+)
+
+// NewCheckCommand returns the cobra command for "check".
+func NewCheckCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "check <subcommand>",
+		Short: "commands for checking properties",
+	}
+	cmd.AddCommand(NewCheckV2StoreCommand())
+	return cmd
+}
+
+var (
+	argCheckV2StoreDataDir string
+)
+
+// NewCheckV2StoreCommand returns the cobra command for "check v2store".
+func NewCheckV2StoreCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "v2store",
+		Short: "Check custom content in v2store",
+		Run:   checkV2StoreRunFunc,
+	}
+	cmd.Flags().StringVar(&argCheckV2StoreDataDir, "data-dir", "", "Required. A data directory not in use by etcd.")
+	cmd.MarkFlagRequired("data-dir")
+	return cmd
+}
+
+func checkV2StoreRunFunc(_ *cobra.Command, _ []string) {
+	err := checkV2StoreDataDir(argCheckV2StoreDataDir)
+	if err != nil {
+		cobrautl.ExitWithError(cobrautl.ExitError, err)
+	}
+}
+
+func checkV2StoreDataDir(dataDir string) error {
+	var (
+		storeClusterPrefix = "/0"
+		storeKeysPrefix    = "/1"
+
+		lg = GetLogger()
+
+		walDir  = filepath.Join(dataDir, "member", "wal")
+		snapDir = filepath.Join(dataDir, "member", "snap")
+	)
+
+	walSnaps, err := wal.ValidSnapshotEntries(lg, walDir)
+	if err != nil {
+		if errors.Is(err, wal.ErrFileNotFound) {
+			return nil
+		}
+		return err
+	}
+
+	ss := snap.New(lg, snapDir)
+	snapshot, err := ss.LoadNewestAvailable(walSnaps)
+	if err != nil {
+		if errors.Is(err, snap.ErrNoSnapshot) {
+			return nil
+		}
+		return err
+	}
+	if snapshot == nil {
+		return nil
+	}
+
+	st := v2store.New(storeClusterPrefix, storeKeysPrefix)
+
+	if err := st.Recovery(snapshot.Data); err != nil {
+		return fmt.Errorf("failed to recover v2store from snapshot: %w", err)
+	}
+	return assertNoV2StoreContent(st)
+}
+
+func assertNoV2StoreContent(st v2store.Store) error {
+	metaOnly, err := membership.IsMetaStoreOnly(st)
+	if err != nil {
+		return err
+	}
+	if metaOnly {
+		return nil
+	}
+	return fmt.Errorf("detected custom content in v2store")
+}
diff --git a/tests/e2e/v2store_deprecation_test.go b/tests/e2e/v2store_deprecation_test.go
index 52dec549b075..08d66c148faf 100644
--- a/tests/e2e/v2store_deprecation_test.go
+++ b/tests/e2e/v2store_deprecation_test.go
@@ -97,3 +97,22 @@ func TestV2DeprecationWriteOnlyNoV2Api(t *testing.T) {
 	_, err = proc.Expect("--enable-v2 and --v2-deprecation=write-only are mutually exclusive")
 	assert.NoError(t, err)
 }
+
+func TestV2DeprecationCheckCustomContentOffline(t *testing.T) {
+	e2e.BeforeTest(t)
+	dataDirPath := t.TempDir()
+
+	createV2store(t, dataDirPath)
+
+	assertVerifyCheckCustomContentOffline(t, dataDirPath)
+}
+
+func assertVerifyCheckCustomContentOffline(t *testing.T, dataDirPath string) {
+	t.Logf("Checking custom content in v2store - %s", dataDirPath)
+
+	proc, err := e2e.SpawnCmd([]string{e2e.BinDir + "/etcdutl", "check", "v2store", "--data-dir=" + dataDirPath}, nil)
+	assert.NoError(t, err)
+
+	_, err = proc.Expect("detected custom content in v2store")
+	assert.NoError(t, err)
+}