Disable listening on IPv6 ports when IPv6 is not supported (#102)

docker/ipv6-disable.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env sh
+set -e
+
+DEFAULT_CONF_FILE="etc/nginx/conf.d/default.conf"
+
+if [ -f "/proc/net/if_inet6" ]; then
+    echo "info: IPv6 available."
+    exit 0
+fi
+
+echo "info: IPv6 not available!"
+echo "info: Removing IPv6 lines from /$DEFAULT_CONF_FILE"
+sed -i 's/\(listen\s*\[::\].*\)$/#\1 # Disabled IPv6/' /${DEFAULT_CONF_FILE}