Allow EXPERIMENTAL tablet type in init-tablet-type (vitessio#20067) (#856)

Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>

Author: ejortegau

go/flags/endtoend/vtcombo.txt

@@ -181,7 +181,7 @@ Flags:
       --init_db_name_override string                                     (init parameter) override the name of the db used by vttablet. Without this flag, the db name defaults to vt_<keyspacename>
       --init_keyspace string                                             (init parameter) keyspace to use for this tablet
       --init_shard string                                                (init parameter) shard to use for this tablet
-      --init_tablet_type string                                          (init parameter) the tablet type to use for this tablet. Can be REPLICA, RDONLY, or SPARE. The default is REPLICA.
+      --init_tablet_type string                                          (init parameter) tablet type to use for this tablet. Valid values are: REPLICA, RDONLY, EXPERIMENTAL and SPARE. The default is REPLICA.
       --init_tags StringMap                                              (init parameter) comma separated list of key:value pairs used to tag the tablet
       --init_timeout duration                                            (init parameter) timeout to use for the init phase. (default 1m0s)
       --jaeger-agent-host string                                         host and port to send spans to. if empty, no tracing will be done

go/flags/endtoend/vttablet.txt

@@ -209,7 +209,7 @@ Flags:
       --init_db_name_override string                                     (init parameter) override the name of the db used by vttablet. Without this flag, the db name defaults to vt_<keyspacename>
       --init_keyspace string                                             (init parameter) keyspace to use for this tablet
       --init_shard string                                                (init parameter) shard to use for this tablet
-      --init_tablet_type string                                          (init parameter) the tablet type to use for this tablet. Can be REPLICA, RDONLY, or SPARE. The default is REPLICA.
+      --init_tablet_type string                                          (init parameter) tablet type to use for this tablet. Valid values are: REPLICA, RDONLY, EXPERIMENTAL and SPARE. The default is REPLICA.
       --init_tags StringMap                                              (init parameter) comma separated list of key:value pairs used to tag the tablet
       --init_timeout duration                                            (init parameter) timeout to use for the init phase. (default 1m0s)
       --jaeger-agent-host string                                         host and port to send spans to. if empty, no tracing will be done

go/vt/vttablet/tabletmanager/tm_init.go

@@ -105,7 +105,7 @@ func registerInitFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&tabletHostname, "tablet_hostname", tabletHostname, "if not empty, this hostname will be assumed instead of trying to resolve it")
 	fs.StringVar(&initKeyspace, "init_keyspace", initKeyspace, "(init parameter) keyspace to use for this tablet")
 	fs.StringVar(&initShard, "init_shard", initShard, "(init parameter) shard to use for this tablet")
-	fs.StringVar(&initTabletType, "init_tablet_type", initTabletType, "(init parameter) the tablet type to use for this tablet. Can be REPLICA, RDONLY, or SPARE. The default is REPLICA.")
+	fs.StringVar(&initTabletType, "init_tablet_type", initTabletType, "(init parameter) tablet type to use for this tablet. Valid values are: REPLICA, RDONLY, EXPERIMENTAL and SPARE. The default is REPLICA.")
 	fs.BoolVar(&initTabletTypeLookup, "init-tablet-type-lookup", initTabletTypeLookup, "(Experimental, init parameter) if enabled, uses tablet alias to look up the tablet type from the existing topology record on restart and use that instead of init_tablet_type. This allows tablets to maintain their changed roles (e.g., RDONLY/DRAINED) across restarts. If disabled or if no topology record exists, init_tablet_type will be used.")
 	fs.StringVar(&initDbNameOverride, "init_db_name_override", initDbNameOverride, "(init parameter) override the name of the db used by vttablet. Without this flag, the db name defaults to vt_<keyspacename>")
 	fs.StringVar(&skipBuildInfoTags, "vttablet_skip_buildinfo_tags", skipBuildInfoTags, "comma-separated list of buildinfo tags to skip from merging with --init_tags. each tag is either an exact match or a regular expression of the form '/regexp/'.")
@@ -254,9 +254,9 @@ func BuildTabletFromInput(alias *topodatapb.TabletAlias, port, grpcPort int32, d
 		return nil, err
 	}
 	switch tabletType {
-	case topodatapb.TabletType_SPARE, topodatapb.TabletType_REPLICA, topodatapb.TabletType_RDONLY:
+	case topodatapb.TabletType_SPARE, topodatapb.TabletType_REPLICA, topodatapb.TabletType_RDONLY, topodatapb.TabletType_EXPERIMENTAL:
 	default:
-		return nil, fmt.Errorf("invalid init_tablet_type %v; can only be REPLICA, RDONLY or SPARE", tabletType)
+		return nil, fmt.Errorf("invalid init_tablet_type %v; can only be REPLICA, RDONLY, EXPERIMENTAL or SPARE", tabletType)
 	}
 
 	buildTags, err := getBuildTags(servenv.AppVersion.ToStringMap(), skipBuildInfoTags)

go/vt/vttablet/tabletmanager/tm_init_test.go

@@ -123,9 +123,19 @@ func TestStartBuildTabletFromInput(t *testing.T) {
 	_, err = BuildTabletFromInput(alias, port, grpcport, nil, collations.MySQL8())
 	assert.Contains(t, err.Error(), "unknown TabletType bad")
 
-	initTabletType = "primary"
-	_, err = BuildTabletFromInput(alias, port, grpcport, nil, collations.MySQL8())
-	assert.Contains(t, err.Error(), "invalid init_tablet_type PRIMARY")
+	for _, invalidType := range []string{"primary", "backup", "restore", "drained"} {
+		initTabletType = invalidType
+		_, err = BuildTabletFromInput(alias, port, grpcport, nil, collations.MySQL8())
+		require.Error(t, err, "expected tablet type %q to be invalid", invalidType)
+		assert.Contains(t, err.Error(), "invalid init_tablet_type")
+	}
+
+	for _, validType := range []string{"replica", "rdonly", "spare", "experimental"} {
+		initTabletType = validType
+		gotTablet, err = BuildTabletFromInput(alias, port, grpcport, nil, collations.MySQL8())
+		require.NoError(t, err, "expected tablet type %q to be valid", validType)
+		assert.NotNil(t, gotTablet)
+	}
 }
 
 func TestBuildTabletFromInputWithBuildTags(t *testing.T) {