op-deployer: Add deploy config inspect command (#12570)

* op-deployer: Add deploy config inspect command

* goimports

* error check

op-deployer/pkg/deployer/inspect/deploy_config.go

+package inspect
+
+import (
+	"fmt"
+
+	"github.com/ethereum-optimism/optimism/op-deployer/pkg/deployer/pipeline"
+	"github.com/ethereum-optimism/optimism/op-deployer/pkg/deployer/state"
+	"github.com/ethereum-optimism/optimism/op-service/ioutil"
+	"github.com/ethereum-optimism/optimism/op-service/jsonutil"
+	"github.com/urfave/cli/v2"
+)
+
+func DeployConfigCLI(cliCtx *cli.Context) error {
+	cliCfg, err := readConfig(cliCtx)
+	if err != nil {
+		return err
+	}
+
+	globalState, err := pipeline.ReadState(cliCfg.Workdir)
+	if err != nil {
+		return fmt.Errorf("failed to read intent: %w", err)
+	}
+	chainState, err := globalState.Chain(cliCfg.ChainID)
+	if err != nil {
+		return fmt.Errorf("failed to find chain state: %w", err)
+	}
+
+	intent := globalState.AppliedIntent
+	if intent == nil {
+		return fmt.Errorf("can only run this command following a full apply")
+	}
+	chainIntent, err := intent.Chain(cliCfg.ChainID)
+	if err != nil {
+		return fmt.Errorf("failed to find chain intent: %w", err)
+	}
+
+	config, err := state.CombineDeployConfig(intent, chainIntent, globalState, chainState)
+	if err != nil {
+		return fmt.Errorf("failed to generate deploy config: %w", err)
+	}
+	if err := jsonutil.WriteJSON(config, ioutil.ToStdOutOrFileOrNoop(cliCfg.Outfile, 0o666)); err != nil {
+		return fmt.Errorf("failed to write deploy config: %w", err)
+	}
+
+	return nil
+}

op-deployer/pkg/deployer/inspect/flags.go

@@ -53,6 +53,14 @@ var Commands = []*cli.Command{
 		Action:    RollupCLI,
 		Flags:     Flags,
 	},
+	{
+		Name:      "deploy-config",
+		Usage:     "outputs the deploy config for an L2 chain",
+		Args:      true,
+		ArgsUsage: "<l2-chain-id>",
+		Action:    DeployConfigCLI,
+		Flags:     Flags,
+	},
 }
 
 type cliConfig struct {

op-deployer/pkg/deployer/state/deploy_config.go

@@ -5,11 +5,11 @@ import (
 	"fmt"
 	"math/big"
 
-	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/rpc"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/log"
 
 	"github.com/ethereum-optimism/optimism/op-chain-ops/genesis"
 	"github.com/ethereum/go-ethereum/common/hexutil"
@@ -101,14 +101,24 @@ func CombineDeployConfig(intent *Intent, chainIntent *ChainIntent, state *State,
 		},
 	}
 
+	if chainState.StartBlock == nil {
+		// These are dummy variables - see below for rationale.
+		num := rpc.LatestBlockNumber
+		cfg.L1StartingBlockTag = &genesis.MarshalableRPCBlockNumberOrHash{
+			BlockNumber: &num,
+		}
+	} else {
+		startHash := chainState.StartBlock.Hash()
+		cfg.L1StartingBlockTag = &genesis.MarshalableRPCBlockNumberOrHash{
+			BlockHash: &startHash,
+		}
+	}
+
 	// The below dummy variables are set in order to allow the deploy
 	// config to pass validation. The validation checks are useful to
 	// ensure that the L2 is properly configured. They are not used by
 	// the L2 genesis script itself.
-	num := rpc.LatestBlockNumber
-	cfg.L1StartingBlockTag = &genesis.MarshalableRPCBlockNumberOrHash{
-		BlockNumber: &num,
-	}
+
 	cfg.L1BlockTime = 12
 	dummyAddr := common.Address{19: 0x01}
 	cfg.SuperchainL1DeployConfig = genesis.SuperchainL1DeployConfig{