cmd: add auto-p2pkey to bootnode command (#350)

As requested in #317, add support for automatically generating a p2pkey if not found. I decided to enable this default since bootnode.

category: bug
ticket: #317

cmd/bootnode.go

@@ -18,9 +18,11 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"os"
 	"time"
 
 	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
 
 	"github.com/obolnetwork/charon/app/errors"
 	"github.com/obolnetwork/charon/app/log"
@@ -29,10 +31,11 @@ import (
 )
 
 type bootnodeConfig struct {
-	DataDir   string
-	HTTPAddr  string
-	P2PConfig p2p.Config
-	LogConfig log.Config
+	DataDir    string
+	HTTPAddr   string
+	P2PConfig  p2p.Config
+	LogConfig  log.Config
+	AutoP2PKey bool
 }
 
 func newBootnodeCmd(runFunc func(context.Context, bootnodeConfig) error) *cobra.Command {
@@ -49,13 +52,18 @@ func newBootnodeCmd(runFunc func(context.Context, bootnodeConfig) error) *cobra.
 	}
 
 	bindDataDirFlag(cmd.Flags(), &config.DataDir)
-	bindBootnodeFlag(cmd.Flags(), &config.HTTPAddr)
+	bindBootnodeFlag(cmd.Flags(), &config.HTTPAddr, &config.AutoP2PKey)
 	bindP2PFlags(cmd.Flags(), &config.P2PConfig)
 	bindLogFlags(cmd.Flags(), &config.LogConfig)
 
 	return cmd
 }
 
+func bindBootnodeFlag(flags *pflag.FlagSet, httpAddr *string, autoP2PKey *bool) {
+	flags.StringVar(httpAddr, "bootnode-http-address", "127.0.0.1:8088", "Listening address for the bootnode http server serving runtime ENR")
+	flags.BoolVar(autoP2PKey, "auto-p2pkey", true, "Automatically create a p2pkey (ecdsa private key used for p2p authentication and ENR) if none found in data directory")
+}
+
 // runBootnode starts a p2p-udp discv5 bootnode.
 func runBootnode(ctx context.Context, config bootnodeConfig) error {
 	ctx = log.WithTopic(ctx, "bootnode")
@@ -65,7 +73,18 @@ func runBootnode(ctx context.Context, config bootnodeConfig) error {
 	}
 
 	key, err := p2p.LoadPrivKey(config.DataDir)
-	if err != nil {
+	if errors.Is(err, os.ErrNotExist) {
+		if !config.AutoP2PKey {
+			return errors.New("p2pkey not found in data dir (run with --auto-p2pkey to auto generate)")
+		}
+
+		log.Info(ctx, "Automatically creating p2pkey", z.Str("path", p2p.KeyPath(config.DataDir)))
+
+		key, err = p2p.NewSavedPrivKey(config.DataDir)
+		if err != nil {
+			return err
+		}
+	} else if err != nil {
 		return err
 	}
 

cmd/bootnode_internal_test.go

@@ -48,3 +48,27 @@ func TestRunBootnode(t *testing.T) {
 	testutil.SkipIfBindErr(t, err)
 	require.NoError(t, err)
 }
+
+func TestRunBootnodeAutoP2P(t *testing.T) {
+	temp, err := os.MkdirTemp("", "")
+	require.NoError(t, err)
+
+	config := bootnodeConfig{
+		DataDir:   temp,
+		LogConfig: log.DefaultConfig(),
+		P2PConfig: p2p.Config{UDPAddr: testutil.AvailableAddr(t).String()},
+		HTTPAddr:  testutil.AvailableAddr(t).String(),
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	err = runBootnode(ctx, config)
+	testutil.SkipIfBindErr(t, err)
+	require.Error(t, err)
+
+	config.AutoP2PKey = true
+	err = runBootnode(ctx, config)
+	testutil.SkipIfBindErr(t, err)
+	require.NoError(t, err)
+}

cmd/run.go

@@ -70,10 +70,6 @@ func bindDataDirFlag(flags *pflag.FlagSet, dataDir *string) {
 	flags.StringVar(dataDir, "data-dir", "./charon/data", "The directory where charon will store all its internal data")
 }
 
-func bindBootnodeFlag(flags *pflag.FlagSet, httpAddr *string) {
-	flags.StringVar(httpAddr, "bootnode-http-address", "127.0.0.1:8088", "Listening address for the bootnode http server serving runtime ENR")
-}
-
 func bindP2PFlags(flags *pflag.FlagSet, config *p2p.Config) {
 	flags.StringVar(&config.DBPath, "p2p-peerdb", "", "Path to store a discv5 peer database. Empty default results in in-memory database.")
 	flags.StringSliceVar(&config.UDPBootnodes, "p2p-bootnodes", nil, "Comma-separated list of discv5 bootnode URLs or ENRs. Manifest ENRs are used if empty. Example URL: enode://<hex node id>@10.3.58.6:30303?discport=30301.")

p2p/k1.go

@@ -24,13 +24,14 @@ import (
 	"github.com/obolnetwork/charon/app/errors"
 )
 
-func p2pKeyPath(datadir string) string {
+// KeyPath returns the p2pkey path relative to the data dir.
+func KeyPath(datadir string) string {
 	return path.Join(datadir, "p2pkey")
 }
 
 // LoadPrivKey returns the ecdsa k1 key saved in the directory.
 func LoadPrivKey(dataDir string) (*ecdsa.PrivateKey, error) {
-	key, err := crypto.LoadECDSA(p2pKeyPath(dataDir))
+	key, err := crypto.LoadECDSA(KeyPath(dataDir))
 	if err != nil {
 		return nil, errors.Wrap(err, "load key")
 	}
@@ -49,7 +50,7 @@ func NewSavedPrivKey(datadir string) (*ecdsa.PrivateKey, error) {
 		return nil, errors.Wrap(err, "gen key")
 	}
 
-	err = crypto.SaveECDSA(p2pKeyPath(datadir), key)
+	err = crypto.SaveECDSA(KeyPath(datadir), key)
 	if err != nil {
 		return nil, errors.Wrap(err, "save key")
 	}