Replace flags usage with pflags

config/config.go

@@ -61,6 +61,7 @@ const (
 )
 
 var (
+	// Deprecated key --> deprecation message (i.e. which key replaces it)
 	deprecatedKeys = map[string]string{}
 
 	errInvalidStakerWeights          = errors.New("staking weights must be positive")

config/config_test.go

@@ -604,10 +604,8 @@ func setupFile(t *testing.T, path string, fileName string, value string) {
 func setupViperFlags() *viper.Viper {
 	v := viper.New()
 	fs := BuildFlagSet()
-	pflag.CommandLine = pflag.NewFlagSet(os.Args[0], pflag.PanicOnError) // flags are now reset
-	pflag.CommandLine.AddGoFlagSet(fs)
 	pflag.Parse()
-	if err := v.BindPFlags(pflag.CommandLine); err != nil {
+	if err := v.BindPFlags(fs); err != nil {
 		log.Fatal(err)
 	}
 	return v

config/flags.go

@@ -4,13 +4,13 @@
 package config
 
 import (
-	"flag"
 	"fmt"
 	"os"
 	"path/filepath"
 	"runtime"
 	"time"
 
+	"github.com/spf13/pflag"
 	"github.com/spf13/viper"
 
 	"github.com/ava-labs/avalanchego/database/leveldb"
@@ -50,12 +50,21 @@ var (
 	defaultChainDataDir         = filepath.Join(defaultUnexpandedDataDir, "chainData")
 )
 
-func addProcessFlags(fs *flag.FlagSet) {
+func deprecateFlags(fs *pflag.FlagSet) error {
+	for key, message := range deprecatedKeys {
+		if err := fs.MarkDeprecated(key, message); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func addProcessFlags(fs *pflag.FlagSet) {
 	// If true, print the version and quit.
 	fs.Bool(VersionKey, false, "If true, print version and quit")
 }
 
-func addNodeFlags(fs *flag.FlagSet) {
+func addNodeFlags(fs *pflag.FlagSet) {
 	// Home directory
 	fs.String(DataDirKey, defaultDataDir, "Sets the base data directory where default sub-directories will be placed unless otherwise specified.")
 	// System
@@ -367,10 +376,8 @@ func addNodeFlags(fs *flag.FlagSet) {
 }
 
 // BuildFlagSet returns a complete set of flags for avalanchego
-func BuildFlagSet() *flag.FlagSet {
-	// TODO parse directly into a *pflag.FlagSet instead of into a *flag.FlagSet
-	// and then putting those into a *plag.FlagSet
-	fs := flag.NewFlagSet(constants.AppName, flag.ContinueOnError)
+func BuildFlagSet() *pflag.FlagSet {
+	fs := pflag.NewFlagSet(constants.AppName, pflag.ContinueOnError)
 	addProcessFlags(fs)
 	addNodeFlags(fs)
 	return fs

config/viper.go

@@ -6,30 +6,30 @@ package config
 import (
 	"bytes"
 	"encoding/base64"
-	"flag"
 	"fmt"
 	"io"
+	"os"
 	"strings"
 
+	"github.com/spf13/pflag"
 	"github.com/spf13/viper"
 )
 
 // BuildViper returns the viper environment from parsing config file from
 // default search paths and any parsed command line flags
-func BuildViper(fs *flag.FlagSet, args []string) (*viper.Viper, error) {
-	pfs, err := buildPFlagSet(fs)
-	if err != nil {
+func BuildViper(fs *pflag.FlagSet, args []string) (*viper.Viper, error) {
+	if err := deprecateFlags(fs); err != nil {
 		return nil, err
 	}
-	if err := pfs.Parse(args); err != nil {
+	if err := fs.Parse(args); err != nil {
 		return nil, err
 	}
 
 	v := viper.New()
 	v.AutomaticEnv()
 	v.SetEnvKeyReplacer(strings.NewReplacer("-", "_"))
 	v.SetEnvPrefix("avago")
-	if err := v.BindPFlags(pfs); err != nil {
+	if err := v.BindPFlags(fs); err != nil {
 		return nil, err
 	}
 
@@ -56,7 +56,7 @@ func BuildViper(fs *flag.FlagSet, args []string) (*viper.Viper, error) {
 	}
 
 	// Config deprecations must be after v.ReadInConfig
-	deprecateConfigs(v, fs.Output())
+	deprecateConfigs(v, os.Stdout)
 	return v, nil
 }