From b089cdd2161a18f1fc127a7f3169bd1fd6f90e60 Mon Sep 17 00:00:00 2001
From: Jim McDonald <Jim@mcdee.net>
Date: Fri, 27 Sep 2019 13:05:16 +0100
Subject: [PATCH] Allow overwriting of default bootstrap node (#3616)

* Allow overwriting of default bootstrap node

* Update shared/cmd/flags.go

Co-Authored-By: Nishant Das <nish1993@hotmail.com>

* Provide warning at more suitable time
---
 beacon-chain/node/node.go     | 3 ++-
 beacon-chain/p2p/discovery.go | 7 +++++++
 shared/cmd/flags.go           | 6 +++---
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/beacon-chain/node/node.go b/beacon-chain/node/node.go
index 52ea11803..51d279ea8 100644
--- a/beacon-chain/node/node.go
+++ b/beacon-chain/node/node.go
@@ -10,6 +10,7 @@ import (
 	"os/signal"
 	"path"
 	"path/filepath"
+	"strings"
 	"sync"
 	"syscall"
 
@@ -215,7 +216,7 @@ func (b *BeaconNode) startDB(ctx *cli.Context) error {
 
 func (b *BeaconNode) registerP2P(ctx *cli.Context) error {
 	// Bootnode ENR may be a filepath to an ENR file.
-	bootnodeAddrs := sliceutil.SplitCommaSeparated(ctx.GlobalStringSlice(cmd.BootstrapNode.Name))
+	bootnodeAddrs := strings.Split(ctx.GlobalString(cmd.BootstrapNode.Name), ",")
 	for i, addr := range bootnodeAddrs {
 		if filepath.Ext(addr) == ".enr" {
 			b, err := ioutil.ReadFile(addr)
diff --git a/beacon-chain/p2p/discovery.go b/beacon-chain/p2p/discovery.go
index 37f481afe..88265dd57 100644
--- a/beacon-chain/p2p/discovery.go
+++ b/beacon-chain/p2p/discovery.go
@@ -100,6 +100,10 @@ func startDHTDiscovery(host core.Host, bootstrapAddr string) error {
 
 func parseBootStrapAddrs(addrs []string) (discv5Nodes []string, kadDHTNodes []string) {
 	for _, addr := range addrs {
+		if addr == "" {
+			// Ignore empty entries
+			continue
+		}
 		_, err := enode.Parse(enode.ValidSchemes, addr)
 		if err == nil {
 			discv5Nodes = append(discv5Nodes, addr)
@@ -112,6 +116,9 @@ func parseBootStrapAddrs(addrs []string) (discv5Nodes []string, kadDHTNodes []st
 		}
 		log.Errorf("Invalid bootstrap address of %s provided", addr)
 	}
+	if len(discv5Nodes) == 0 && len(kadDHTNodes) == 0 {
+		log.Warn("No bootstrap addresses supplied")
+	}
 	return discv5Nodes, kadDHTNodes
 }
 
diff --git a/shared/cmd/flags.go b/shared/cmd/flags.go
index 86a9fce4a..961783e72 100644
--- a/shared/cmd/flags.go
+++ b/shared/cmd/flags.go
@@ -64,10 +64,10 @@ var (
 		Usage: "Connect with this peer. This flag may be used multiple times.",
 	}
 	// BootstrapNode tells the beacon node which bootstrap node to connect to
-	BootstrapNode = cli.StringSliceFlag{
+	BootstrapNode = cli.StringFlag{
 		Name:  "bootstrap-node",
-		Usage: "The address of bootstrap node. Beacon node will connect for peer discovery via DHT",
-		Value: &cli.StringSlice{"/dns4/prylabs.net/tcp/30001/p2p/16Uiu2HAm7Qwe19vz9WzD2Mxn7fXd1vgHHp4iccuyq7TxwRXoAGfc"},
+		Usage: "The address of bootstrap node. Beacon node will connect for peer discovery via DHT.  Multiple nodes can be separated with a comma",
+		Value: "/dns4/prylabs.net/tcp/30001/p2p/16Uiu2HAm7Qwe19vz9WzD2Mxn7fXd1vgHHp4iccuyq7TxwRXoAGfc",
 	}
 	// RelayNode tells the beacon node which relay node to connect to.
 	RelayNode = cli.StringFlag{