From a79ce64e82b484f58989f6cdb36b8219d929fa2a Mon Sep 17 00:00:00 2001
From: Timo Behrendt <t.behrendt@t00n.de>
Date: Fri, 7 Nov 2025 17:14:14 +0100
Subject: [PATCH] fix(externalIpProvider/plain): when reading response body
 (#54)

Fixing an error where the service crashes reading the response body, when no content-length header was provided in the response.

Reviewed-on: https://gitea.t000-n.de/t.behrendt/realDynDNS/pulls/54
Reviewed-by: branch-buddy <branch-buddy@t00n.de>
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>
---
 pkg/externalIpProvider/plain/plain.go | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/pkg/externalIpProvider/plain/plain.go b/pkg/externalIpProvider/plain/plain.go
index 3fed9ad..cc0b112 100644
--- a/pkg/externalIpProvider/plain/plain.go
+++ b/pkg/externalIpProvider/plain/plain.go
@@ -2,6 +2,7 @@ package externalIpProvider
 
 import (
 	"errors"
+	"io"
 	"net"
 	"net/http"
 	"net/url"
@@ -40,12 +41,15 @@ func (p *ExternalIpProviderImplPlain) GetExternalIp() (net.IP, error) {
 	}
 
 	if res.StatusCode != 200 {
+		res.Body.Close()
 		return nil, errors.New("unexpected status code")
 	}
 
-	responseBody := make([]byte, res.ContentLength)
-	res.Body.Read(responseBody)
-	defer res.Body.Close()
+	responseBody, err := io.ReadAll(res.Body)
+	res.Body.Close()
+	if err != nil {
+		return nil, err
+	}
 
 	parsedIp := net.ParseIP(string(responseBody))
 	if parsedIp == nil {