From 784db4bbd61fb42914200cf5bcafd5afa2d2ff4a Mon Sep 17 00:00:00 2001
From: ramin <raminkeene@gmail.com>
Date: Tue, 6 Aug 2024 15:00:04 +0100
Subject: [PATCH] fix(libs/utils): rely on DNS for rpc/grpc requests to core
 (#3624)

---
 libs/utils/address.go           | 13 ++++++++-----
 libs/utils/address_test.go      |  2 ++
 nodebuilder/core/config.go      |  2 +-
 nodebuilder/core/config_test.go | 13 +++++++++++--
 4 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/libs/utils/address.go b/libs/utils/address.go
index c20d11ad06..b4efca7bf3 100644
--- a/libs/utils/address.go
+++ b/libs/utils/address.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"net/netip"
 	"strings"
 )
 
@@ -24,19 +25,21 @@ func SanitizeAddr(addr string) (string, error) {
 	return addr, nil
 }
 
-// ValidateAddr sanitizes the given address and verifies that it is a valid IP or hostname. The
-// sanitized address is returned.
+// ValidateAddr sanitizes the given address and verifies that it
+// is a valid IP or hostname. The sanitized address is returned.
 func ValidateAddr(addr string) (string, error) {
 	addr, err := SanitizeAddr(addr)
 	if err != nil {
 		return addr, err
 	}
 
-	ip := net.ParseIP(addr)
-	if ip != nil {
-		return addr, nil
+	// if the address is a valid IP, return it
+	ip, err := netip.ParseAddr(addr)
+	if err == nil {
+		return ip.String(), nil
 	}
 
+	// if the address is not a valid IP, resolve it
 	resolved, err := net.ResolveIPAddr("ip4", addr)
 	if err != nil {
 		return addr, err
diff --git a/libs/utils/address_test.go b/libs/utils/address_test.go
index b18ead91a1..39fd0a2ec5 100644
--- a/libs/utils/address_test.go
+++ b/libs/utils/address_test.go
@@ -53,6 +53,8 @@ func TestValidateAddr(t *testing.T) {
 		{addr: "https://celestia.org", want: want{unresolved: true}},
 		// Testcase: hostname is valid, but no schema
 		{addr: "celestia.org", want: want{unresolved: true}},
+		// Testcase: localhost
+		{addr: "localhost", want: want{addr: "127.0.0.1"}},
 	}
 
 	for _, tt := range tests {
diff --git a/nodebuilder/core/config.go b/nodebuilder/core/config.go
index a211fac231..b82be1d809 100644
--- a/nodebuilder/core/config.go
+++ b/nodebuilder/core/config.go
@@ -44,7 +44,7 @@ func (cfg *Config) Validate() error {
 		return fmt.Errorf("nodebuilder/core: grpc port is not set")
 	}
 
-	ip, err := utils.ValidateAddr(cfg.IP)
+	ip, err := utils.SanitizeAddr(cfg.IP)
 	if err != nil {
 		return err
 	}
diff --git a/nodebuilder/core/config_test.go b/nodebuilder/core/config_test.go
index 9b06d6918d..6535e28807 100644
--- a/nodebuilder/core/config_test.go
+++ b/nodebuilder/core/config_test.go
@@ -26,6 +26,15 @@ func TestValidate(t *testing.T) {
 			cfg:       Config{},
 			expectErr: false,
 		},
+		{
+			name: "hostname preserved",
+			cfg: Config{
+				IP:       "celestia.org",
+				RPCPort:  DefaultRPCPort,
+				GRPCPort: DefaultGRPCPort,
+			},
+			expectErr: false,
+		},
 		{
 			name: "missing RPC port",
 			cfg: Config{
@@ -43,13 +52,13 @@ func TestValidate(t *testing.T) {
 			expectErr: true,
 		},
 		{
-			name: "invalid IP",
+			name: "invalid IP, but will be accepted as host and not raise an error",
 			cfg: Config{
 				IP:       "invalid-ip",
 				RPCPort:  DefaultRPCPort,
 				GRPCPort: DefaultGRPCPort,
 			},
-			expectErr: true,
+			expectErr: false,
 		},
 		{
 			name: "invalid RPC port",