title: How do I resolve the error "unrecognized options: --enable-password-save" when building openvpn under alpine linux?
body: <p>I am building a custom <code>openvpn</code> client within a <code>Docker</code> container that is based on a standard <code>node-alpine</code> image.</p>
  
  <p>The (trimmed) docker image looks like:</p>
  
  <pre><code>FROM node:8.4-alpine
  MAINTAINER: Dave &lt;redacted@redacted.redacted&gt;
  
  RUN apk add --update --no-cache \
      file \
      make \
      gcc \
      g++ \
      python \
      wget
  
  # install openVPN
  
  RUN wget https://swupdate.openvpn.org/community/releases/openvpn-2.4.3.tar.gz --no-check-certificate
  RUN gunzip openvpn-2.4.3.tar.gz
  RUN tar -xvf openvpn-2.4.3.tar
  
  WORKDIR openvpn-2.4.3
  RUN ./configure --enable-password-save
  RUN make
  RUN make install
  
  # ... the rest of the file
  </code></pre>
  
  <p>When I build this I get an error</p>
  
  <pre><code>configure: WARNING: unrecognized options: --enable-password-save
  </code></pre>
  
  <p>then the checks continue for a while before failing at</p>
  
  <pre><code>checking whether TUNSETPERSIST is declared... no
  configure: error: no tap header could be found
  </code></pre>
  
  <p>What am I missing?</p>