op-chain-ops: check-migration-quick

Adds a new tool that can be used as part of the migration that checks
a minimal amount of information to ensure that the database migration
was successful. It checks the extradata in the block header for the
bedrock magic and errors if its not found. It will log information
about the block header as well.

op-chain-ops/cmd/check-migration-quick/main.go

+package main
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+
+	"github.com/mattn/go-isatty"
+	"github.com/urfave/cli"
+
+	"github.com/ethereum-optimism/optimism/op-chain-ops/db"
+	"github.com/ethereum-optimism/optimism/op-chain-ops/genesis"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+func main() {
+	log.Root().SetHandler(log.StreamHandler(os.Stderr, log.TerminalFormat(isatty.IsTerminal(os.Stderr.Fd()))))
+
+	app := &cli.App{
+		Name:  "check-migration-quick",
+		Usage: "Quick check for a migrated database that only checks the header magic in the extradata",
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:     "db-path",
+				Usage:    "Path to database",
+				Required: true,
+			},
+			&cli.IntFlag{
+				Name:  "db-cache",
+				Usage: "LevelDB cache size in mb",
+				Value: 1024,
+			},
+			&cli.IntFlag{
+				Name:  "db-handles",
+				Usage: "LevelDB number of handles",
+				Value: 60,
+			},
+		},
+		Action: func(ctx *cli.Context) error {
+			dbCache := ctx.Int("db-cache")
+			dbHandles := ctx.Int("db-handles")
+
+			ldb, err := db.Open(ctx.String("db-path"), dbCache, dbHandles)
+			if err != nil {
+				return err
+			}
+
+			hash := rawdb.ReadHeadHeaderHash(ldb)
+			log.Info("Reading chain tip from database", "hash", hash)
+			num := rawdb.ReadHeaderNumber(ldb, hash)
+			if num == nil {
+				return fmt.Errorf("cannot find header number for %s", hash)
+			}
+
+			header := rawdb.ReadHeader(ldb, hash, *num)
+			log.Info("Read header from database", "number", *num)
+
+			log.Info(
+				"Header info",
+				"parentHash", header.ParentHash.Hex(),
+				"root", header.Root.Hex(),
+				"number", header.Number,
+				"gasLimit", header.GasLimit,
+				"time", header.Time,
+				"extra", hexutil.Encode(header.Extra),
+			)
+
+			if !bytes.Equal(header.Extra, genesis.BedrockTransitionBlockExtraData) {
+				return fmt.Errorf("expected extra data to be %x, but got %x", genesis.BedrockTransitionBlockExtraData, header.Extra)
+			}
+
+			if err := ldb.Close(); err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+
+	if err := app.Run(os.Args); err != nil {
+		log.Crit("error in migration", "err", err)
+	}
+}