Install UFW at runtime if needed only

openvpn/start.sh

@@ -50,6 +50,8 @@ dockerize -template /etc/transmission/environment-variables.tmpl:/etc/transmissi
 TRANSMISSION_CONTROL_OPTS="--script-security 2 --up-delay --up /etc/transmission/start.sh --down /etc/transmission/stop.sh"
 
 if [ "true" = "$ENABLE_UFW" ]; then
+  apk add --no-cache ufw@testing
+
   # Enable firewall
   echo "enabling firewall"
   sed -i -e s/IPV6=yes/IPV6=no/ /etc/default/ufw