Install UFW with dockerfile

Dockerfile.alpine

@@ -5,7 +5,8 @@ VOLUME /data
 VOLUME /config
 
 ENV DOCKERIZE_VERSION=v0.6.0
-RUN apk --no-cache add dumb-init openvpn shadow transmission-daemon \
+RUN echo "@testing http://dl-cdn.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories \
+    && apk --no-cache add dumb-init ip6tables ufw@testing openvpn shadow transmission-daemon \
     && echo "Install dockerize $DOCKERIZE_VERSION" \
     && wget -qO- https://github.com/jwilder/dockerize/releases/download/$DOCKERIZE_VERSION/dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz | tar xz -C /usr/bin \
     && mkdir -p /opt/transmission-ui/combustion-release /opt/transmission-ui/kettu \