title: Nginx directory /etc/nginx is empty after install with docker
body: <p>I try to install nginx with rtmp module and my own patch but after install the folder /erc/nginx is empty.</p>
  
  <p>My Dockerfile</p>
  
  <pre><code>FROM debian:10
  
  ARG ROOT=/tmp/build
  ARG NGINXV=1.18.0
  ARG FILE_PATH=/tmp/patch
  ARG INSTANCE=nginx
  
  RUN mkdir -p $FILE_PATH
  COPY patch/nginx-rtmp-module-sl1.patch $FILE_PATH
  
  RUN apt-get update &amp;&amp; apt-get install -y \
          git \
          libpcre3 \
          libpcre3-dev \
          openssl \
          libssl-dev \
          zlib1g \
          zlib1g-dev \
          libzmq3-dev \
          wget \
          patch \
          gcc \
          make
  
  RUN   mkdir -p $ROOT \
        &amp;&amp; cd $ROOT \
        &amp;&amp; rm -rf nginx-$NGINXV nginx-rtmp-module nginx-push-stream-module \
        &amp;&amp; [ -f nginx-$NGINXV.tar.gz ] || wget https://nginx.org/download/nginx-$NGINXV.tar.gz \
        &amp;&amp; tar xvzf nginx-$NGINXV.tar.gz \
        &amp;&amp; git clone https://github.com/wandenberg/nginx-push-stream-module \
        &amp;&amp; git clone https://github.com/arut/nginx-rtmp-module \
        &amp;&amp; cd nginx-rtmp-module \
        &amp;&amp; patch -p1 &lt; /$FILE_PATH/nginx-rtmp-module-sl1.patch \
        &amp;&amp; cd .. \
        &amp;&amp; cd nginx-$NGINXV \
        &amp;&amp; ./configure \
              --prefix=/etc/$INSTANCE \
              --sbin-path=/usr/sbin/$INSTANCE \
              --conf-path=/etc/$INSTANCE/$INSTANCE.conf \
              --error-log-path=/var/log/$INSTANCE/error.log \
              --http-log-path=/var/log/$INSTANCE/access.log \
              --pid-path=/var/run/$INSTANCE.pid \
              --lock-path=/var/run/$INSTANCE.lock \
              --http-client-body-temp-path=/var/cache/$INSTANCE/client_temp \
              --http-proxy-temp-path=/var/cache/$INSTANCE/proxy_temp \
              --http-fastcgi-temp-path=/var/cache/$INSTANCE/fastcgi_temp \
              --http-uwsgi-temp-path=/var/cache/$INSTANCE/uwsgi_temp \
              --http-scgi-temp-path=/var/cache/$INSTANCE/scgi_temp \
              --user=www-data \
              --group=www-data \
              --with-ld-opt=-lzmq \
              --add-module=../nginx-push-stream-module \
              --add-module=../nginx-rtmp-module \
              --with-http_ssl_module \
              --with-http_v2_module \
              --with-http_realip_module \
              --with-http_sub_module \
              --with-http_secure_link_module \
              --with-http_stub_status_module \
              --with-stream \
              --with-stream=dynamic \
              --with-stream_ssl_module \
              --with-stream_realip_module \
              --with-cc-opt='-Wno-error=implicit-fallthrough' \
           &amp;&amp; make -j 8 \
           &amp;&amp; strip objs/nginx \
           &amp;&amp; echo `pwd`/objs/nginx
  
  COPY start.sh /start.sh
  CMD ["sh", "/start.sh"]
  </code></pre>
  
  <p>I thought this is because of i used volumes with docker-compose, but i got the same error if i build the container without some volumes.</p>
  
  <p>I also don't know how to rebuild the container without cache. I tried to stop and rm the container but when i try rebuild it docker just uses cache</p>