From b48bb26c5fcea9555d7e80d26f1f65cf1788338e Mon Sep 17 00:00:00 2001
From: Mikkel Oscar Lyderik Larsen <mikkel.larsen@zalando.de>
Date: Mon, 27 Nov 2023 11:53:42 +0100
Subject: [PATCH] Make routegroup client IPv6 compatible

Signed-off-by: Mikkel Oscar Lyderik Larsen <mikkel.larsen@zalando.de>
---
 source/skipper_routegroup.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/source/skipper_routegroup.go b/source/skipper_routegroup.go
index 2c3475ac4..3854722cc 100644
--- a/source/skipper_routegroup.go
+++ b/source/skipper_routegroup.go
@@ -210,7 +210,8 @@ func NewRouteGroupSource(timeout time.Duration, token, tokenPath, apiServerURL,
 	apiServer := u.String()
 	// strip port if well known port, because of TLS certificate match
 	if u.Scheme == "https" && u.Port() == "443" {
-		apiServer = "https://" + u.Hostname()
+		// correctly handle IPv6 addresses by keeping surrounding `[]`.
+		apiServer = "https://" + strings.TrimSuffix(u.Host, ":443")
 	}
 
 	sc := &routeGroupSource{