op-node: Add command to dump rollup configs

op-node/cmd/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"github.com/ethereum-optimism/optimism/op-node/cmd/networks"
 	"os"
 
 	"github.com/urfave/cli/v2"
@@ -57,6 +58,10 @@ func main() {
 			Name:        "doc",
 			Subcommands: doc.NewSubcommands(metrics.NewMetrics("default")),
 		},
+		{
+			Name:        "networks",
+			Subcommands: networks.Subcommands,
+		},
 	}
 
 	ctx := opio.WithInterruptBlocker(context.Background())

op-node/cmd/networks/cmd.go

+package networks
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	opnode "github.com/ethereum-optimism/optimism/op-node"
+	"github.com/ethereum-optimism/optimism/op-node/flags"
+	oplog "github.com/ethereum-optimism/optimism/op-service/log"
+	"github.com/urfave/cli/v2"
+)
+
+var Subcommands = []*cli.Command{
+	{
+		Name:  "dump-rollup-config",
+		Usage: "Dumps network configs",
+		Flags: []cli.Flag{
+			flags.Network,
+		},
+		Action: func(ctx *cli.Context) error {
+			logCfg := oplog.ReadCLIConfig(ctx)
+			logger := oplog.NewLogger(oplog.AppOut(ctx), logCfg)
+
+			network := ctx.String(flags.Network.Name)
+			if network == "" {
+				return errors.New("must specify a network name")
+			}
+
+			rCfg, err := opnode.NewRollupConfig(logger, ctx)
+			if err != nil {
+				return err
+			}
+
+			out, err := json.MarshalIndent(rCfg, "", "  ")
+			if err != nil {
+				return err
+			}
+			fmt.Println(string(out))
+			return nil
+		},
+	},
+}