REP-4790 Exclude all Mongosync internal DBs, including those used by the embedded verifier (#19)

This also includes some linting fixes and some tooling updates.

Author: autarch

.gitignore

@@ -1,4 +1,6 @@
+dev-bin/
 go.sum
+golangci-lint
 migration_verifier
 internal/verifier/mongodb_exec/
 verifier_expansion.yml

internal/verifier/change_stream.go

@@ -50,7 +50,7 @@ func (verifier *Verifier) HandleChangeStreamEvent(ctx context.Context, changeEve
 	case "update":
 		return verifier.InsertChangeEventRecheckDoc(ctx, changeEvent)
 	default:
-		return fmt.Errorf(`Not supporting: "` + changeEvent.OpType + `" events`)
+		return errors.New(`Not supporting: "` + changeEvent.OpType + `" events`)
 	}
 }
 

internal/verifier/list_namespaces.go

@@ -10,8 +10,8 @@ import (
 	"go.mongodb.org/mongo-driver/mongo/options"
 )
 
-const (
-	MongosyncMetaDB = "mongosync_reserved_for_internal_use"
+var (
+	MongosyncMetaDBsPattern = `^mongosync_(internal|reserved)_`
 )
 
 var (
@@ -29,9 +29,14 @@ func ListAllUserCollections(ctx context.Context, logger *logger.Logger, client *
 	excludedDBs := []string{}
 	excludedDBs = append(excludedDBs, additionalExcludedDBs...)
 	excludedDBs = append(excludedDBs, ExcludedSystemDBs...)
-	excludedDBs = append(excludedDBs, MongosyncMetaDB)
 
-	dbNames, err := client.ListDatabaseNames(ctx, bson.D{{"name", bson.D{{"$nin", excludedDBs}}}})
+	var excluded []any
+	for _, e := range excludedDBs {
+		excluded = append(excluded, e)
+	}
+	excluded = append(excluded, primitive.Regex{Pattern: MongosyncMetaDBsPattern})
+
+	dbNames, err := client.ListDatabaseNames(ctx, bson.D{{"name", bson.D{{"$nin", excluded}}}})
 	if err != nil {
 		return nil, err
 	}

internal/verifier/migration_verifier_test.go

@@ -1265,8 +1265,14 @@ func (suite *MultiDataVersionTestSuite) TestVerifierNamespaceList() {
 	suite.Require().NoError(err)
 	err = suite.dstMongoClient.Database("testDb4").CreateCollection(ctx, "testColl6")
 	suite.Require().NoError(err)
+	err = suite.dstMongoClient.Database("local").CreateCollection(ctx, "testColl7")
+	suite.Require().NoError(err)
 	err = suite.dstMongoClient.Database("mongosync_reserved_for_internal_use").CreateCollection(ctx, "globalState")
 	suite.Require().NoError(err)
+	err = suite.dstMongoClient.Database("mongosync_reserved_for_verification_src_metadata").CreateCollection(ctx, "auditor")
+	suite.Require().NoError(err)
+	err = suite.dstMongoClient.Database("mongosync_reserved_for_verification_dst_metadata").CreateCollection(ctx, "auditor")
+	suite.Require().NoError(err)
 	err = verifier.setupAllNamespaceList(ctx)
 	suite.Require().NoError(err)
 	suite.ElementsMatch([]string{"testDb1.testColl1", "testDb1.testColl2", "testDb2.testColl3", "testDb2.testColl4",

internal/verifier/verification_task.go

@@ -71,7 +71,7 @@ type VerificationTask struct {
 	// both clusters but don’t match.
 	FailedDocs []VerificationResult `bson:"failed_docs,omitempty"`
 
-	QueryFilter QueryFilter `bson:"query_filter"          json:"query_filter"`
+	QueryFilter QueryFilter `bson:"query_filter" json:"query_filter"`
 
 	// DocumentCount is set when the verifier is done with the task
 	// (whether we found mismatches or not).

precious.toml

@@ -0,0 +1,15 @@
+# When adding new tidiers, consider what labels it should have. If it's fast, set labels like this:
+#
+#     labels = [ "default", "fast-tidy" ]
+#
+# "Fast" here means anything less than 0.1s. These tidiers are intended to be invoked frequently,
+# for example from editors on save. Slower tidiers should only be invoked manually.
+
+exclude = "vendor/**"
+
+[commands.goimports]
+type = "tidy"
+include = "**/*.go"
+cmd = [ "$PRECIOUS_ROOT/dev-bin/goimports", "-w" ]
+ok-exit-codes = [0]
+labels = [ "default", "fast-tidy" ]