Set showExpandedEvents in change streams for server v6+. (#54)

Since migration-verifier forbids DDL events during verification, it should set `showExpandedEvents` so that it can fail on events like `create` or `shardCollection`. This changeset sets that flag.

This also redoes version detection to avoid typing weirdness.

For convenience, this copies mslices.Of() from mongosync.

Author: FGasper

internal/partitions/partition.go

@@ -137,7 +137,7 @@ func (p *Partition) FindCmd(
 // (e.g. use the partitions on the source to read the destination for verification)
 // If the passed-in buildinfo indicates a mongodb version < 5.0, type bracketing is not used.
 // filterAndPredicates is a slice of filter criteria that's used to construct the "filter" field in the find option.
-func (p *Partition) GetFindOptions(buildInfo *bson.M, filterAndPredicates bson.A) bson.D {
+func (p *Partition) GetFindOptions(buildInfo *util.BuildInfo, filterAndPredicates bson.A) bson.D {
 	if p == nil {
 		if len(filterAndPredicates) > 0 {
 			return bson.D{{"filter", bson.D{{"$and", filterAndPredicates}}}}
@@ -160,16 +160,9 @@ func (p *Partition) GetFindOptions(buildInfo *bson.M, filterAndPredicates bson.A
 		allowTypeBracketing := false
 		if buildInfo != nil {
 			allowTypeBracketing = true
-			versionArray, ok := (*buildInfo)["versionArray"].(bson.A)
-			//bson values are int32 or int64, never int.
-			if ok {
-				majorVersion, ok := versionArray[0].(int32)
-				if ok {
-					allowTypeBracketing = majorVersion < 5
-				} else {
-					majorVersion64, _ := versionArray[0].(int64)
-					allowTypeBracketing = majorVersion64 < 5
-				}
+
+			if buildInfo.VersionArray != nil {
+				allowTypeBracketing = buildInfo.VersionArray[0] < 5
 			}
 		}
 		if !allowTypeBracketing {

internal/partitions/partition_test.go

@@ -77,43 +77,38 @@ func (suite *UnitTestSuite) TestVersioning() {
 	filter := getFilterFromFindOptions(findOptions)
 	suite.Require().Equal(expectedFilter, filter)
 
-	// 6.0 (int64)
-	findOptions = partition.GetFindOptions(&bson.M{"versionArray": bson.A{int64(6), int64(0), int64(0), int64(0)}}, nil)
-	filter = getFilterFromFindOptions(findOptions)
-	suite.Require().Equal(expectedFilter, filter)
-
 	// 6.0
-	findOptions = partition.GetFindOptions(&bson.M{"versionArray": bson.A{int32(6), int32(0), int32(0), int32(0)}}, nil)
+	findOptions = partition.GetFindOptions(&util.BuildInfo{VersionArray: []int{6, 0, 0}}, nil)
 	filter = getFilterFromFindOptions(findOptions)
 	suite.Require().Equal(expectedFilter, filter)
 
 	// 5.3.0.9
-	findOptions = partition.GetFindOptions(&bson.M{"versionArray": bson.A{int32(5), int32(3), int32(0), int32(9)}}, nil)
+	findOptions = partition.GetFindOptions(&util.BuildInfo{VersionArray: []int{5, 3, 0, 9}}, nil)
 	filter = getFilterFromFindOptions(findOptions)
 	suite.Require().Equal(expectedFilter, filter)
 
 	// 7.1.3.5
-	findOptions = partition.GetFindOptions(&bson.M{"versionArray": bson.A{int32(7), int32(1), int32(3), int32(5)}}, nil)
+	findOptions = partition.GetFindOptions(&util.BuildInfo{VersionArray: []int{7, 1, 3, 5}}, nil)
 	filter = getFilterFromFindOptions(findOptions)
 	suite.Require().Equal(expectedFilter, filter)
 
 	// 4.4 (int64)
-	findOptions = partition.GetFindOptions(&bson.M{"versionArray": bson.A{int64(4), int64(4), int64(0), int64(0)}}, nil)
+	findOptions = partition.GetFindOptions(&util.BuildInfo{VersionArray: []int{4, 4, 0, 0}}, nil)
 	filter = getFilterFromFindOptions(findOptions)
 	suite.Require().Equal(expectedFilterWithTypeBracketing, filter)
 
 	// 4.4
-	findOptions = partition.GetFindOptions(&bson.M{"versionArray": bson.A{int32(4), int32(4), int32(0), int32(0)}}, nil)
+	findOptions = partition.GetFindOptions(&util.BuildInfo{VersionArray: []int{4, 4, 0, 0}}, nil)
 	filter = getFilterFromFindOptions(findOptions)
 	suite.Require().Equal(expectedFilterWithTypeBracketing, filter)
 
 	// 4.2
-	findOptions = partition.GetFindOptions(&bson.M{"versionArray": bson.A{int32(4), int32(2), int32(0), int32(0)}}, nil)
+	findOptions = partition.GetFindOptions(&util.BuildInfo{VersionArray: []int{4, 2, 0, 0}}, nil)
 	filter = getFilterFromFindOptions(findOptions)
 	suite.Require().Equal(expectedFilterWithTypeBracketing, filter)
 
 	// No version array -- assume old, require type bracketing.
-	findOptions = partition.GetFindOptions(&bson.M{"notVersionArray": bson.A{6, int32(0), int32(0), int32(0)}}, nil)
+	findOptions = partition.GetFindOptions(&util.BuildInfo{}, nil)
 	filter = getFilterFromFindOptions(findOptions)
 	suite.Require().Equal(expectedFilterWithTypeBracketing, filter)
 }

internal/util/buildinfo.go

@@ -0,0 +1,31 @@
+package util
+
+import (
+	"context"
+
+	"github.com/10gen/migration-verifier/mbson"
+	"github.com/pkg/errors"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+)
+
+type BuildInfo struct {
+	VersionArray []int
+}
+
+func GetBuildInfo(ctx context.Context, client *mongo.Client) (BuildInfo, error) {
+	commandResult := client.Database("admin").RunCommand(ctx, bson.D{{"buildinfo", 1}})
+
+	rawResp, err := commandResult.Raw()
+	if err != nil {
+		return BuildInfo{}, errors.Wrap(err, "failed to fetch build info")
+	}
+
+	bi := BuildInfo{}
+	_, err = mbson.RawLookup(rawResp, &bi.VersionArray, "versionArray")
+	if err != nil {
+		return BuildInfo{}, errors.Wrap(err, "failed to decode build info version array")
+	}
+
+	return bi, nil
+}

internal/verifier/change_stream.go

@@ -293,6 +293,10 @@ func (verifier *Verifier) StartChangeStream(ctx context.Context) error {
 		SetMaxAwaitTime(1 * time.Second).
 		SetFullDocument(options.UpdateLookup)
 
+	if verifier.srcBuildInfo.VersionArray[0] >= 6 {
+		opts = opts.SetCustomPipeline(bson.M{"showExpandedEvents": true})
+	}
+
 	savedResumeToken, err := verifier.loadChangeStreamResumeToken(ctx)
 	if err != nil {
 		return errors.Wrap(err, "failed to load persisted change stream resume token")

internal/verifier/change_stream_test.go

@@ -5,6 +5,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/10gen/migration-verifier/internal/util"
+	"github.com/10gen/migration-verifier/mslices"
 	"github.com/pkg/errors"
 	"github.com/samber/lo"
 	"github.com/stretchr/testify/require"
@@ -35,6 +37,12 @@ func TestChangeStreamFilter(t *testing.T) {
 // terminates that verifier, updates the source cluster, starts a new
 // verifier with change stream, and confirms that things look as they should.
 func (suite *IntegrationTestSuite) TestChangeStreamResumability() {
+	suite.Require().NoError(
+		suite.srcMongoClient.
+			Database(suite.DBNameForTest()).
+			CreateCollection(suite.Context(), "testColl"),
+	)
+
 	func() {
 		verifier1 := suite.BuildVerifier()
 		ctx, cancel := context.WithCancel(context.Background())
@@ -43,7 +51,7 @@ func (suite *IntegrationTestSuite) TestChangeStreamResumability() {
 		suite.Require().NoError(err)
 	}()
 
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(suite.Context())
 	defer cancel()
 
 	_, err := suite.srcMongoClient.
@@ -219,19 +227,26 @@ func (suite *IntegrationTestSuite) TestNoStartAtTime() {
 }
 
 func (suite *IntegrationTestSuite) TestWithChangeEventsBatching() {
-	verifier := suite.BuildVerifier()
+	ctx := suite.Context()
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	db := suite.srcMongoClient.Database(suite.DBNameForTest())
+	coll1 := db.Collection("testColl1")
+	coll2 := db.Collection("testColl2")
+
+	for _, coll := range mslices.Of(coll1, coll2) {
+		suite.Require().NoError(db.CreateCollection(ctx, coll.Name()))
+	}
+
+	verifier := suite.BuildVerifier()
 
 	suite.Require().NoError(verifier.StartChangeStream(ctx))
 
-	_, err := suite.srcMongoClient.Database("testDb").Collection("testColl1").InsertOne(ctx, bson.D{{"_id", 1}})
+	_, err := coll1.InsertOne(ctx, bson.D{{"_id", 1}})
 	suite.Require().NoError(err)
-	_, err = suite.srcMongoClient.Database("testDb").Collection("testColl1").InsertOne(ctx, bson.D{{"_id", 2}})
+	_, err = coll1.InsertOne(ctx, bson.D{{"_id", 2}})
 	suite.Require().NoError(err)
 
-	_, err = suite.srcMongoClient.Database("testDb").Collection("testColl2").InsertOne(ctx, bson.D{{"_id", 1}})
+	_, err = coll2.InsertOne(ctx, bson.D{{"_id", 1}})
 	suite.Require().NoError(err)
 
 	var rechecks []bson.M
@@ -245,6 +260,7 @@ func (suite *IntegrationTestSuite) TestWithChangeEventsBatching() {
 		500*time.Millisecond,
 		"the verifier should flush a recheck doc after a batch",
 	)
+
 }
 
 func (suite *IntegrationTestSuite) TestManyInsertsBeforeWritesOff() {
@@ -304,3 +320,40 @@ func (suite *IntegrationTestSuite) testInsertsBeforeWritesOff(docsCount int) {
 
 	suite.Assert().Equal(docsCount, totalFailed, "all source docs should be missing")
 }
+
+func (suite *IntegrationTestSuite) TestCreateForbidden() {
+	ctx := suite.Context()
+	buildInfo, err := util.GetBuildInfo(ctx, suite.srcMongoClient)
+	suite.Require().NoError(err)
+
+	if buildInfo.VersionArray[0] < 6 {
+		suite.T().Skipf("This test requires server v6+. (Found: %v)", buildInfo.VersionArray)
+	}
+
+	verifier := suite.BuildVerifier()
+
+	// start verifier
+	verifierRunner := RunVerifierCheck(suite.Context(), suite.T(), verifier)
+
+	// wait for generation 0 to end
+	verifierRunner.AwaitGenerationEnd()
+
+	db := suite.srcMongoClient.Database(suite.DBNameForTest())
+	coll := db.Collection("mycoll")
+	suite.Require().NoError(
+		db.CreateCollection(ctx, coll.Name()),
+	)
+
+	// The error from the create event will come either at WritesOff
+	// or when we finalize the change stream.
+	err = verifier.WritesOff(ctx)
+	if err == nil {
+		err = verifierRunner.Await()
+	}
+
+	suite.Require().Error(err, "should detect forbidden create event")
+
+	eventErr := UnknownEventError{}
+	suite.Require().ErrorAs(err, &eventErr)
+	suite.Assert().Equal("create", eventErr.Event.OpType)
+}

internal/verifier/check.go

@@ -236,6 +236,9 @@ func (verifier *Verifier) CheckDriver(ctx context.Context, filter map[string]any
 		// paying attention. Also, this should not matter too much because any failures will be
 		// caught again on the next iteration.
 		if verifier.writesOff {
+			verifier.logger.Debug().
+				Msg("Waiting for change stream to end.")
+
 			// It's necessary to wait for the change stream to finish before incrementing the
 			// generation number, or the last changes will not be checked.
 			verifier.mux.Unlock()

internal/verifier/migration_verifier.go

@@ -89,8 +89,8 @@ type Verifier struct {
 	metaClient         *mongo.Client
 	srcClient          *mongo.Client
 	dstClient          *mongo.Client
-	srcBuildInfo       *bson.M
-	dstBuildInfo       *bson.M
+	srcBuildInfo       *util.BuildInfo
+	dstBuildInfo       *util.BuildInfo
 	numWorkers         int
 	failureDisplaySize int64
 
@@ -312,21 +312,33 @@ func (verifier *Verifier) SetSrcURI(ctx context.Context, uri string) error {
 	var err error
 	verifier.srcClient, err = mongo.Connect(ctx, opts)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, "failed to connect to source %#q", uri)
 	}
-	verifier.srcBuildInfo, err = getBuildInfo(ctx, verifier.srcClient)
-	return err
+
+	buildInfo, err := util.GetBuildInfo(ctx, verifier.srcClient)
+	if err != nil {
+		return errors.Wrap(err, "failed to read source build info")
+	}
+
+	verifier.srcBuildInfo = &buildInfo
+	return nil
 }
 
 func (verifier *Verifier) SetDstURI(ctx context.Context, uri string) error {
 	opts := verifier.getClientOpts(uri)
 	var err error
 	verifier.dstClient, err = mongo.Connect(ctx, opts)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, "failed to connect to destination %#q", uri)
 	}
-	verifier.dstBuildInfo, err = getBuildInfo(ctx, verifier.dstClient)
-	return err
+
+	buildInfo, err := util.GetBuildInfo(ctx, verifier.dstClient)
+	if err != nil {
+		return errors.Wrap(err, "failed to read destination build info")
+	}
+
+	verifier.dstBuildInfo = &buildInfo
+	return nil
 }
 
 func (verifier *Verifier) SetServerPort(port int) {
@@ -457,7 +469,7 @@ func (verifier *Verifier) maybeAppendGlobalFilterToPredicates(predicates bson.A)
 	return append(predicates, verifier.globalFilter)
 }
 
-func (verifier *Verifier) getDocumentsCursor(ctx context.Context, collection *mongo.Collection, buildInfo *bson.M,
+func (verifier *Verifier) getDocumentsCursor(ctx context.Context, collection *mongo.Collection, buildInfo *util.BuildInfo,
 	startAtTs *primitive.Timestamp, task *VerificationTask) (*mongo.Cursor, error) {
 	var findOptions bson.D
 	runCommandOptions := options.RunCmd()
@@ -1510,16 +1522,3 @@ func (verifier *Verifier) getNamespaces(ctx context.Context, fieldName string) (
 	}
 	return namespaces, nil
 }
-
-func getBuildInfo(ctx context.Context, client *mongo.Client) (*bson.M, error) {
-	commandResult := client.Database("admin").RunCommand(ctx, bson.D{{"buildinfo", 1}})
-	if commandResult.Err() != nil {
-		return nil, commandResult.Err()
-	}
-	var buildInfoMap bson.M
-	err := commandResult.Decode(&buildInfoMap)
-	if err != nil {
-		return nil, err
-	}
-	return &buildInfoMap, nil
-}