cmd: migrate to urfave/cli/v2 (#24751)

This change updates our urfave/cli dependency to the v2 branch of the library.
There are some Go API changes in cli v2:

- Flag values can now be accessed using the methods ctx.Bool,
  ctx.Int, ctx.String, ... regardless of whether the flag is 'local' or
  'global'.

- v2 has built-in support for flag categories. Our home-grown category
  system is removed and the categories of flags are assigned as part of
  the flag definition.

For users, there is only one observable difference with cli v2: flags must now
strictly appear before regular arguments. For example, the following command is
now invalid:

   geth account import mykey.json --password file.txt

Instead, the command must be invoked as follows:

   geth account import --password file.txt mykey.json

cmd/ethkey/changepassword.go

@@ -23,15 +23,15 @@ import (
 
 	"github.com/ethereum/go-ethereum/accounts/keystore"
 	"github.com/ethereum/go-ethereum/cmd/utils"
-	"gopkg.in/urfave/cli.v1"
+	"github.com/urfave/cli/v2"
 )
 
-var newPassphraseFlag = cli.StringFlag{
+var newPassphraseFlag = &cli.StringFlag{
 	Name:  "newpasswordfile",
 	Usage: "the file that contains the new password for the keyfile",
 }
 
-var commandChangePassphrase = cli.Command{
+var commandChangePassphrase = &cli.Command{
 	Name:      "changepassword",
 	Usage:     "change the password on a keyfile",
 	ArgsUsage: "<keyfile>",

cmd/ethkey/generate.go

@@ -26,7 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/google/uuid"
-	"gopkg.in/urfave/cli.v1"
+	"github.com/urfave/cli/v2"
 )
 
 type outputGenerate struct {
@@ -35,17 +35,17 @@ type outputGenerate struct {
 }
 
 var (
-	privateKeyFlag = cli.StringFlag{
+	privateKeyFlag = &cli.StringFlag{
 		Name:  "privatekey",
 		Usage: "file containing a raw private key to encrypt",
 	}
-	lightKDFFlag = cli.BoolFlag{
+	lightKDFFlag = &cli.BoolFlag{
 		Name:  "lightkdf",
 		Usage: "use less secure scrypt parameters",
 	}
 )
 
-var commandGenerate = cli.Command{
+var commandGenerate = &cli.Command{
 	Name:      "generate",
 	Usage:     "generate new keyfile",
 	ArgsUsage: "[ <keyfile> ]",

cmd/ethkey/inspect.go

@@ -24,7 +24,7 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/keystore"
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/crypto"
-	"gopkg.in/urfave/cli.v1"
+	"github.com/urfave/cli/v2"
 )
 
 type outputInspect struct {
@@ -34,13 +34,13 @@ type outputInspect struct {
 }
 
 var (
-	privateFlag = cli.BoolFlag{
+	privateFlag = &cli.BoolFlag{
 		Name:  "private",
 		Usage: "include the private key in the output",
 	}
 )
 
-var commandInspect = cli.Command{
+var commandInspect = &cli.Command{
 	Name:      "inspect",
 	Usage:     "inspect a keyfile",
 	ArgsUsage: "<keyfile>",

cmd/ethkey/main.go

@@ -21,7 +21,7 @@ import (
 	"os"
 
 	"github.com/ethereum/go-ethereum/internal/flags"
-	"gopkg.in/urfave/cli.v1"
+	"github.com/urfave/cli/v2"
 )
 
 const (
@@ -36,23 +36,22 @@ var app *cli.App
 
 func init() {
 	app = flags.NewApp(gitCommit, gitDate, "an Ethereum key manager")
-	app.Commands = []cli.Command{
+	app.Commands = []*cli.Command{
 		commandGenerate,
 		commandInspect,
 		commandChangePassphrase,
 		commandSignMessage,
 		commandVerifyMessage,
 	}
-	cli.CommandHelpTemplate = flags.OriginCommandHelpTemplate
 }
 
 // Commonly used command line flags.
 var (
-	passphraseFlag = cli.StringFlag{
+	passphraseFlag = &cli.StringFlag{
 		Name:  "passwordfile",
 		Usage: "the file that contains the password for the keyfile",
 	}
-	jsonFlag = cli.BoolFlag{
+	jsonFlag = &cli.BoolFlag{
 		Name:  "json",
 		Usage: "output JSON instead of human-readable format",
 	}

cmd/ethkey/message.go

@@ -26,19 +26,19 @@ import (
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
-	"gopkg.in/urfave/cli.v1"
+	"github.com/urfave/cli/v2"
 )
 
 type outputSign struct {
 	Signature string
 }
 
-var msgfileFlag = cli.StringFlag{
+var msgfileFlag = &cli.StringFlag{
 	Name:  "msgfile",
 	Usage: "file containing the message to sign/verify",
 }
 
-var commandSignMessage = cli.Command{
+var commandSignMessage = &cli.Command{
 	Name:      "signmessage",
 	Usage:     "sign a message",
 	ArgsUsage: "<keyfile> <message>",
@@ -89,7 +89,7 @@ type outputVerify struct {
 	RecoveredPublicKey string
 }
 
-var commandVerifyMessage = cli.Command{
+var commandVerifyMessage = &cli.Command{
 	Name:      "verifymessage",
 	Usage:     "verify the signature of a signed message",
 	ArgsUsage: "<address> <signature> <message>",
@@ -144,7 +144,7 @@ It is possible to refer to a file containing the message.`,
 
 func getMessage(ctx *cli.Context, msgarg int) []byte {
 	if file := ctx.String(msgfileFlag.Name); file != "" {
-		if len(ctx.Args()) > msgarg {
+		if ctx.NArg() > msgarg {
 			utils.Fatalf("Can't use --msgfile and message argument at the same time.")
 		}
 		msg, err := os.ReadFile(file)
@@ -152,9 +152,9 @@ func getMessage(ctx *cli.Context, msgarg int) []byte {
 			utils.Fatalf("Can't read message file: %v", err)
 		}
 		return msg
-	} else if len(ctx.Args()) == msgarg+1 {
+	} else if ctx.NArg() == msgarg+1 {
 		return []byte(ctx.Args().Get(msgarg))
 	}
-	utils.Fatalf("Invalid number of arguments: want %d, got %d", msgarg+1, len(ctx.Args()))
+	utils.Fatalf("Invalid number of arguments: want %d, got %d", msgarg+1, ctx.NArg())
 	return nil
 }

cmd/ethkey/utils.go

@@ -23,7 +23,7 @@ import (
 	"strings"
 
 	"github.com/ethereum/go-ethereum/cmd/utils"
-	"gopkg.in/urfave/cli.v1"
+	"github.com/urfave/cli/v2"
 )
 
 // getPassphrase obtains a passphrase given by the user.  It first checks the