From c563bc848ee5fbd41a35e805ec90207aee62b081 Mon Sep 17 00:00:00 2001
From: bobbypage <david@porter.me>
Date: Sun, 13 Sep 2020 01:07:06 +0000
Subject: [PATCH] Only set ipv6 killswitch if ipv6 interface exists

---
 entrypoint.sh | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/entrypoint.sh b/entrypoint.sh
index d2305ec..4f3b1d7 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -3,7 +3,7 @@
 set -e
 
 configs=`find /etc/wireguard -type f -printf "%f\n"`
-if [[ -z $configs ]]; then
+if [[ -z "$configs" ]]; then
     echo "No configuration files found in /etc/wireguard" >&2
     exit 1
 fi
@@ -18,8 +18,12 @@ docker_network_rule=$([ ! -z "$docker_network" ] && echo "! -d $docker_network"
 iptables -I OUTPUT ! -o $interface -m mark ! --mark $(wg show $interface fwmark) -m addrtype ! --dst-type LOCAL $docker_network_rule -j REJECT
 
 docker6_network="$(ip -o addr show dev eth0 | awk '$3 == "inet6" {print $4}')"
-docker6_network_rule=$([ ! -z "$docker6_network" ] && echo "! -d $docker6_network" || echo "")
-ip6tables -I OUTPUT ! -o $interface -m mark ! --mark $(wg show $interface fwmark) -m addrtype ! --dst-type LOCAL $docker6_network_rule -j REJECT
+if [[ -z "$docker6_network" ]]; then
+    echo "Skipping ipv6 killswitch setup since ipv6 interface was not found..." >&2
+else
+    docker6_network_rule=$([ ! -z "$docker6_network" ] && echo "! -d $docker6_network" || echo "")
+    ip6tables -I OUTPUT ! -o $interface -m mark ! --mark $(wg show $interface fwmark) -m addrtype ! --dst-type LOCAL $docker6_network_rule -j REJECT
+fi
 
 shutdown () {
     wg-quick down $interface