Improvements

Signed-off-by: Matt Lord <mattalord@gmail.com>

go/vt/vtctl/workflow/framework_test.go

@@ -304,7 +304,7 @@ func (tmc *testTMClient) CreateVReplicationWorkflow(ctx context.Context, tablet
 	defer tmc.mu.Unlock()
 
 	if expect := tmc.createVReplicationWorkflowRequests[tablet.Alias.Uid]; expect != nil {
-		if !proto.Equal(expect.req, req) {
+		if expect.req != nil && !proto.Equal(expect.req, req) {
 			return nil, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "unexpected CreateVReplicationWorkflow request: got %+v, want %+v", req, expect)
 		}
 		if expect.res != nil {
@@ -443,7 +443,7 @@ func (tmc *testTMClient) VReplicationExec(ctx context.Context, tablet *topodatap
 
 	qrs := tmc.vrQueries[int(tablet.Alias.Uid)]
 	if len(qrs) == 0 {
-		return nil, fmt.Errorf("tablet %v does not expect any more queries: %s", tablet, query)
+		return nil, fmt.Errorf("tablet %v does not expect any more queries: %q", tablet, query)
 	}
 	matched := false
 	if qrs[0].query[0] == '/' {

go/vt/vtctl/workflow/materializer.go

@@ -45,6 +45,7 @@ import (
 	tabletmanagerdatapb "vitess.io/vitess/go/vt/proto/tabletmanagerdata"
 	vschemapb "vitess.io/vitess/go/vt/proto/vschema"
 	vtctldatapb "vitess.io/vitess/go/vt/proto/vtctldata"
+	vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
 )
 
 const (
@@ -113,13 +114,11 @@ func (mz *materializer) createWorkflowStreams(req *tabletmanagerdatapb.CreateVRe
 	if err := validateNewWorkflow(mz.ctx, mz.ts, mz.tmc, mz.ms.TargetKeyspace, mz.ms.Workflow); err != nil {
 		return err
 	}
+
 	err := mz.buildMaterializer()
 	if err != nil {
 		return err
 	}
-	if err := mz.deploySchema(); err != nil {
-		return err
-	}
 
 	var workflowSubType binlogdatapb.VReplicationWorkflowSubType
 	workflowSubType, err = mz.getWorkflowSubType()
@@ -133,6 +132,10 @@ func (mz *materializer) createWorkflowStreams(req *tabletmanagerdatapb.CreateVRe
 	}
 	req.Options = optionsJSON
 
+	if err := mz.deploySchema(); err != nil {
+		return err
+	}
+
 	return mz.forAllTargets(func(target *topo.ShardInfo) error {
 		targetPrimary, err := mz.ts.GetTablet(mz.ctx, target.PrimaryAlias)
 		if err != nil {
@@ -268,15 +271,15 @@ func (mz *materializer) deploySchema() error {
 	return forAllShards(mz.targetShards, func(target *topo.ShardInfo) error {
 		allTables := []string{"/.*/"}
 
-		hasTargetTable := map[string]bool{}
 		req := &tabletmanagerdatapb.GetSchemaRequest{Tables: allTables}
 		targetSchema, err := schematools.GetSchema(mz.ctx, mz.ts, mz.tmc, target.PrimaryAlias, req)
 		if err != nil {
 			return err
 		}
 
+		hasTargetTable := make(map[string]*tabletmanagerdatapb.TableDefinition, len(targetSchema.TableDefinitions))
 		for _, td := range targetSchema.TableDefinitions {
-			hasTargetTable[td.Name] = true
+			hasTargetTable[td.Name] = td
 		}
 
 		targetTablet, err := mz.ts.GetTablet(mz.ctx, target.PrimaryAlias)
@@ -286,12 +289,16 @@ func (mz *materializer) deploySchema() error {
 
 		var applyDDLs []string
 		for _, ts := range mz.ms.TableSettings {
-			if hasTargetTable[ts.TargetTable] {
-				// Table already exists.
+			if td := hasTargetTable[ts.TargetTable]; td != nil {
+				// Table already exists. Let's be sure that it doesn't already have data.
+				if td.RowCount > 0 {
+					return vterrors.Errorf(vtrpcpb.Code_FAILED_PRECONDITION,
+						"target table %s exists in the %s keyspace and is not empty", td.Name, target.Keyspace())
+				}
 				continue
 			}
 			if ts.CreateDdl == "" {
-				return fmt.Errorf("target table %v does not exist and there is no create ddl defined", ts.TargetTable)
+				return fmt.Errorf("target table %s does not exist and there is no create ddl defined", ts.TargetTable)
 			}
 
 			var err error

go/vt/vtctl/workflow/materializer_test.go

@@ -2177,10 +2177,11 @@ func TestCreateLookupVindexFailures(t *testing.T) {
 	require.NoError(t, err)
 
 	testcases := []struct {
-		description   string
-		input         *vschemapb.Keyspace
-		createRequest *createVReplicationWorkflowRequestResponse
-		err           string
+		description     string
+		input           *vschemapb.Keyspace
+		createRequest   *createVReplicationWorkflowRequestResponse
+		vrepExecQueries []string
+		err             string
 	}{
 		{
 			description: "dup vindex",
@@ -2431,7 +2432,7 @@ func TestCreateLookupVindexFailures(t *testing.T) {
 			err: fmt.Sprintf("table other not found in the %s keyspace", ms.TargetKeyspace),
 		},
 		{
-			description: "workflow name already exists",
+			description: "workflow creation error",
 			input: &vschemapb.Keyspace{
 				Vindexes: map[string]*vschemapb.Vindex{
 					"v2": {
@@ -2452,7 +2453,7 @@ func TestCreateLookupVindexFailures(t *testing.T) {
 					},
 				},
 			},
-			//vrQuery: "CREATE TABLE `t1_lkp` (\n`c1` INT,\n  `keyspace_id` varbinary(128),\n  PRIMARY KEY (`c1`)\n)",
+			vrepExecQueries: []string{"CREATE TABLE `t1_lkp` (\n`c1` INT,\n  `keyspace_id` varbinary(128),\n  PRIMARY KEY (`c1`)\n)"},
 			createRequest: &createVReplicationWorkflowRequestResponse{
 				req: nil,
 				res: &tabletmanagerdatapb.CreateVReplicationWorkflowResponse{},
@@ -2468,10 +2469,12 @@ func TestCreateLookupVindexFailures(t *testing.T) {
 				Keyspace: ms.TargetKeyspace,
 				Vindex:   tcase.input,
 			}
-			if tcase.createRequest != nil {
-				for _, tablet := range env.tablets {
-					if tablet.Keyspace == ms.TargetKeyspace {
-						env.tmc.expectVRQuery(int(tablet.Alias.Uid), "CREATE TABLE `t1_lkp` (\n`c1` INT,\n  `keyspace_id` varbinary(128),\n  PRIMARY KEY (`c1`)\n)", &sqltypes.Result{})
+			for _, tablet := range env.tablets {
+				if tablet.Keyspace == ms.TargetKeyspace {
+					for _, vrq := range tcase.vrepExecQueries {
+						env.tmc.expectVRQuery(int(tablet.Alias.Uid), vrq, &sqltypes.Result{})
+					}
+					if tcase.createRequest != nil {
 						env.tmc.expectCreateVReplicationWorkflowRequest(tablet.Alias.Uid, tcase.createRequest)
 					}
 				}