server: Move setting storage version to schema

server/storage/schema/schema.go

@@ -0,0 +1,66 @@
+// Copyright 2021 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 schema
+
+import (
+	"fmt"
+
+	"github.com/coreos/go-semver/semver"
+	"go.uber.org/zap"
+
+	"go.etcd.io/etcd/server/v3/storage/backend"
+)
+
+var (
+	V3_5 = semver.Version{Major: 3, Minor: 5}
+	V3_6 = semver.Version{Major: 3, Minor: 6}
+)
+
+// UpdateStorageSchema updates storage version.
+func UpdateStorageSchema(lg *zap.Logger, tx backend.BatchTx) error {
+	tx.Lock()
+	defer tx.Unlock()
+	v, err := detectStorageVersion(lg, tx)
+	if err != nil {
+		return fmt.Errorf("cannot determine storage version: %w", err)
+	}
+	switch *v {
+	case V3_5:
+		lg.Warn("setting storage version", zap.String("storage-version", V3_6.String()))
+		// All meta keys introduced in v3.6 should be filled in here.
+		UnsafeSetStorageVersion(tx, &V3_6)
+	case V3_6:
+	default:
+		lg.Warn("unknown storage version", zap.String("storage-version", v.String()))
+	}
+	return nil
+}
+
+func detectStorageVersion(lg *zap.Logger, tx backend.ReadTx) (*semver.Version, error) {
+	v := UnsafeReadStorageVersion(tx)
+	if v != nil {
+		return v, nil
+	}
+	confstate := UnsafeConfStateFromBackend(lg, tx)
+	if confstate == nil {
+		return nil, fmt.Errorf("missing %q key", MetaConfStateName)
+	}
+	_, term := UnsafeReadConsistentIndex(tx)
+	if term == 0 {
+		return nil, fmt.Errorf("missing %q key", MetaTermKeyName)
+	}
+	copied := V3_5
+	return &copied, nil
+}

server/storage/schema/schema_test.go

@@ -0,0 +1,119 @@
+// Copyright 2021 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 schema
+
+import (
+	"testing"
+	"time"
+
+	"github.com/coreos/go-semver/semver"
+	"github.com/stretchr/testify/assert"
+	"go.etcd.io/etcd/api/v3/version"
+	"go.etcd.io/etcd/raft/v3/raftpb"
+	"go.etcd.io/etcd/server/v3/storage/backend"
+	betesting "go.etcd.io/etcd/server/v3/storage/backend/testing"
+	"go.uber.org/zap"
+)
+
+func TestUpdateStorageVersion(t *testing.T) {
+	tcs := []struct {
+		name             string
+		version          string
+		metaKeys         [][]byte
+		expectVersion    *semver.Version
+		expectError      bool
+		expectedErrorMsg string
+	}{
+		{
+			name:             `Backend before 3.6 without "confState" should be rejected`,
+			version:          "",
+			expectVersion:    nil,
+			expectError:      true,
+			expectedErrorMsg: `cannot determine storage version: missing "confState" key`,
+		},
+		{
+			name:             `Backend before 3.6 without "term" should be rejected`,
+			version:          "",
+			metaKeys:         [][]byte{MetaConfStateName},
+			expectVersion:    nil,
+			expectError:      true,
+			expectedErrorMsg: `cannot determine storage version: missing "term" key`,
+		},
+		{
+			name:          "Backend with 3.5 with all metadata keys should be upgraded to v3.6",
+			version:       "",
+			metaKeys:      [][]byte{MetaTermKeyName, MetaConfStateName},
+			expectVersion: &semver.Version{Major: 3, Minor: 6},
+		},
+		{
+			name:          "Backend in 3.6.0 should be skipped",
+			version:       "3.6.0",
+			metaKeys:      [][]byte{MetaTermKeyName, MetaConfStateName, MetaStorageVersionName},
+			expectVersion: &semver.Version{Major: 3, Minor: 6},
+		},
+		{
+			name:          "Backend with current version should be skipped",
+			version:       version.Version,
+			metaKeys:      [][]byte{MetaTermKeyName, MetaConfStateName, MetaStorageVersionName},
+			expectVersion: &semver.Version{Major: 3, Minor: 6},
+		},
+		{
+			name:          "Backend in 3.7.0 should be skipped",
+			version:       "3.7.0",
+			metaKeys:      [][]byte{MetaTermKeyName, MetaConfStateName, MetaStorageVersionName, []byte("future-key")},
+			expectVersion: &semver.Version{Major: 3, Minor: 7},
+		},
+	}
+	for _, tc := range tcs {
+		t.Run(tc.name, func(t *testing.T) {
+			lg := zap.NewNop()
+			be, tmpPath := betesting.NewTmpBackend(t, time.Microsecond, 10)
+			tx := be.BatchTx()
+			if tx == nil {
+				t.Fatal("batch tx is nil")
+			}
+			tx.Lock()
+			UnsafeCreateMetaBucket(tx)
+			for _, k := range tc.metaKeys {
+				switch string(k) {
+				case string(MetaConfStateName):
+					MustUnsafeSaveConfStateToBackend(lg, tx, &raftpb.ConfState{})
+				case string(MetaTermKeyName):
+					UnsafeUpdateConsistentIndex(tx, 1, 1, false)
+				default:
+					tx.UnsafePut(Meta, k, []byte{})
+				}
+			}
+			if tc.version != "" {
+				UnsafeSetStorageVersion(tx, semver.New(tc.version))
+			}
+			tx.Unlock()
+			be.ForceCommit()
+			be.Close()
+
+			b := backend.NewDefaultBackend(tmpPath)
+			defer b.Close()
+			err := UpdateStorageSchema(lg, b.BatchTx())
+			if (err != nil) != tc.expectError {
+				t.Errorf("UpgradeStorage(...) = %+v, expected error: %v", err, tc.expectError)
+			}
+			if err != nil && err.Error() != tc.expectedErrorMsg {
+				t.Errorf("UpgradeStorage(...) = %q, expected error message: %q", err, tc.expectedErrorMsg)
+			}
+			v := UnsafeReadStorageVersion(b.BatchTx())
+			assert.Equal(t, tc.expectVersion, v)
+		})
+	}
+}