DeleteTablet: allow deletion of old master tablet without -allow_mast…

…er flag

Signed-off-by: deepthi <deepthi@planetscale.com>

go/vt/wrangler/tablet.go

@@ -109,7 +109,13 @@ func (wr *Wrangler) DeleteTablet(ctx context.Context, tabletAlias *topodatapb.Ta
  if err != nil {
  return err
  }
- wasMaster := ti.Type == topodatapb.TabletType_MASTER
+ si, err := wr.ts.GetShard(ctx, ti.Keyspace, ti.Shard)
+ if err != nil {
+ return err
+ }
+
+ // the true master tablet will have the same MasterTermStartTime as the shard
+ wasMaster := ti.Type == topodatapb.TabletType_MASTER && topoproto.TabletAliasEqual(si.MasterAlias, tabletAlias) && logutil.ProtoToTime(ti.MasterTermStartTime).Equal(logutil.ProtoToTime(si.MasterTermStartTime))
  if wasMaster && !allowMaster {
  return fmt.Errorf("cannot delete tablet %v as it is a master, use allow_master flag", topoproto.TabletAliasString(tabletAlias))
  }

go/vt/wrangler/tablet_test.go

@@ -17,11 +17,13 @@ limitations under the License.
 package wrangler
 
 import (
+ "strings"
  "testing"
 
  "golang.org/x/net/context"
  "vitess.io/vitess/go/vt/logutil"
  topodatapb "vitess.io/vitess/go/vt/proto/topodata"
+ "vitess.io/vitess/go/vt/topo"
  "vitess.io/vitess/go/vt/topo/memorytopo"
 )
 
@@ -56,3 +58,102 @@ func TestInitTabletShardConversion(t *testing.T) {
  t.Errorf("Got wrong tablet.KeyRange, got %v expected 80-c0", ti.KeyRange)
  }
 }
+
+// TestDeleteTabletBasic tests delete of non-master tablet
+func TestDeleteTabletBasic(t *testing.T) {
+ cell := "cell1"
+ ts := memorytopo.NewServer(cell)
+ wr := New(logutil.NewConsoleLogger(), ts, nil)
+
+ tablet := &topodatapb.Tablet{
+ Alias: &topodatapb.TabletAlias{
+ Cell: cell,
+ Uid: 1,
+ },
+ Shard: "0",
+ }
+
+ if err := wr.InitTablet(context.Background(), tablet, false /*allowMasterOverride*/, true /*createShardAndKeyspace*/, false /*allowUpdate*/); err != nil {
+ t.Fatalf("InitTablet failed: %v", err)
+ }
+
+ if _, err := ts.GetTablet(context.Background(), tablet.Alias); err != nil {
+ t.Fatalf("GetTablet failed: %v", err)
+ }
+
+ if err := wr.DeleteTablet(context.Background(), tablet.Alias, false); err != nil {
+ t.Fatalf("DeleteTablet failed: %v", err)
+ }
+}
+
+// TestDeleteTabletTrueMaster tests that you can delete a true master tablet
+// only if allowMaster is set to true
+func TestDeleteTabletTrueMaster(t *testing.T) {
+ cell := "cell1"
+ ts := memorytopo.NewServer(cell)
+ wr := New(logutil.NewConsoleLogger(), ts, nil)
+
+ _, err := ts.GetOrCreateShard(context.Background(), "test", "0")
+ tablet := &topodatapb.Tablet{
+ Alias: &topodatapb.TabletAlias{
+ Cell: cell,
+ Uid: 1,
+ },
+ Keyspace: "test",
+ Shard: "0",
+ Type: topodatapb.TabletType_MASTER,
+ }
+
+ if err := wr.InitTablet(context.Background(), tablet, false /*allowMasterOverride*/, false /*createShardAndKeyspace*/, false /*allowUpdate*/); err != nil {
+ t.Fatalf("InitTablet failed: %v", err)
+ }
+ if _, err := ts.GetTablet(context.Background(), tablet.Alias); err != nil {
+ t.Fatalf("GetTablet failed: %v", err)
+ }
+
+ // set MasterAlias and MasterTermStartTime on shard to match chosen master tablet
+ _, err = ts.UpdateShardFields(context.Background(), "test", "0", func(si *topo.ShardInfo) error {
+ si.MasterAlias = tablet.Alias
+ si.MasterTermStartTime = tablet.MasterTermStartTime
+ return nil
+ })
+
+ err = wr.DeleteTablet(context.Background(), tablet.Alias, false)
+ wantError := "as it is a master, use allow_master flag"
+ if err == nil || !strings.Contains(err.Error(), wantError) {
+ t.Fatalf("DeleteTablet on master: want error = %v, got error = %v", wantError, err)
+ }
+
+ if err := wr.DeleteTablet(context.Background(), tablet.Alias, true); err != nil {
+ t.Fatalf("DeleteTablet failed: %v", err)
+ }
+}
+
+// TestDeleteTabletFalseMaster tests that you can delete a false master tablet
+// with allowMaster set to false
+func TestDeleteTabletFalseMaster(t *testing.T) {
+ cell := "cell1"
+ ts := memorytopo.NewServer(cell)
+ wr := New(logutil.NewConsoleLogger(), ts, nil)
+
+ tablet := &topodatapb.Tablet{
+ Alias: &topodatapb.TabletAlias{
+ Cell: cell,
+ Uid: 1,
+ },
+ Keyspace: "test",
+ Shard: "0",
+ Type: topodatapb.TabletType_MASTER,
+ }
+
+ if err := wr.InitTablet(context.Background(), tablet, false /*allowMasterOverride*/, true /*createShardAndKeyspace*/, false /*allowUpdate*/); err != nil {
+ t.Fatalf("InitTablet failed: %v", err)
+ }
+ if _, err := ts.GetTablet(context.Background(), tablet.Alias); err != nil {
+ t.Fatalf("GetTablet failed: %v", err)
+ }
+
+ if err := wr.DeleteTablet(context.Background(), tablet.Alias, false); err != nil {
+ t.Fatalf("DeleteTablet failed: %v", err)
+ }
+}