cell_info.go

package vtctl

import (
	"flag"
	"fmt"
	"strings"

	"golang.org/x/net/context"

	"github.com/youtube/vitess/go/vt/topo"
	"github.com/youtube/vitess/go/vt/wrangler"

	topodatapb "github.com/youtube/vitess/go/vt/proto/topodata"
)

// This file contains the Cells command group for vtctl.

const cellsGroupName = "Cells"

func init() {
	addCommandGroup(cellsGroupName)

	addCommand(cellsGroupName, command{
		"AddCellInfo",
		commandAddCellInfo,
		"[-server_address <addr>] [-root <root>] <cell>",
		"Registers a local topology service in a new cell by creating the CellInfo with the provided parameters. The address will be used to connect to the topology service, and we'll put Vitess data starting at the provided root."})

	addCommand(cellsGroupName, command{
		"UpdateCellInfo",
		commandUpdateCellInfo,
		"[-server_address <addr>] [-root <root>] <cell>",
		"Updates the content of a CellInfo with the provided parameters. If a value is empty, it is not updated. The CellInfo will be created if it doesn't exist."})

	addCommand(cellsGroupName, command{
		"DeleteCellInfo",
		commandDeleteCellInfo,
		"<cell>",
		"Deletes the CellInfo for the provided cell. The cell cannot be referenced by any Shard record."})

	addCommand(cellsGroupName, command{
		"GetCellInfoNames",
		commandGetCellInfoNames,
		"",
		"Lists all the cells for which we have a CellInfo object, meaning we have a local topology service registered."})

	addCommand(cellsGroupName, command{
		"GetCellInfo",
		commandGetCellInfo,
		"<cell>",
		"Prints a JSON representation of the CellInfo for a cell."})
}

func commandAddCellInfo(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
	serverAddress := subFlags.String("server_address", "", "The address the topology server is using for that cell.")
	root := subFlags.String("root", "", "The root path the topology server is using for that cell.")
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 1 {
		return fmt.Errorf("the <cell> argument is required for the AddCellInfo command")
	}
	cell := subFlags.Arg(0)

	return wr.TopoServer().CreateCellInfo(ctx, cell, &topodatapb.CellInfo{
		ServerAddress: *serverAddress,
		Root:          *root,
	})
}

func commandUpdateCellInfo(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
	serverAddress := subFlags.String("server_address", "", "The address the topology server is using for that cell.")
	root := subFlags.String("root", "", "The root path the topology server is using for that cell.")
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 1 {
		return fmt.Errorf("the <cell> argument is required for the UpdateCellInfo command")
	}
	cell := subFlags.Arg(0)

	return wr.TopoServer().UpdateCellInfoFields(ctx, cell, func(ci *topodatapb.CellInfo) error {
		if (*serverAddress == "" || ci.ServerAddress == *serverAddress) &&
			(*root == "" || ci.Root == *root) {
			return topo.ErrNoUpdateNeeded
		}
		if *serverAddress != "" {
			ci.ServerAddress = *serverAddress
		}
		if *root != "" {
			ci.Root = *root
		}
		return nil
	})
}

func commandDeleteCellInfo(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 1 {
		return fmt.Errorf("the <cell> argument is required for the DeleteCellInfo command")
	}
	cell := subFlags.Arg(0)

	return wr.TopoServer().DeleteCellInfo(ctx, cell)
}

func commandGetCellInfoNames(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 0 {
		return fmt.Errorf("GetCellInfoNames command takes no parameter")
	}
	names, err := wr.TopoServer().GetCellInfoNames(ctx)
	if err != nil {
		return err
	}
	wr.Logger().Printf("%v\n", strings.Join(names, "\n"))
	return nil
}

func commandGetCellInfo(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 1 {
		return fmt.Errorf("the <cell> argument is required for the GetCellInfo command")
	}

	cell := subFlags.Arg(0)
	ci, err := wr.TopoServer().GetCellInfo(ctx, cell)
	if err != nil {
		return err
	}
	return printJSON(wr.Logger(), ci)
}