title: Libresolv dependency for Alpine linux
body: <p>I have Alpine v3.7 Docker image and to put things short, I am installing OCI8 extension for PHP.</p>
  
  <p>When doing the <code>php -v</code> I get the following error:</p>
  
  <blockquote>
    <p>PHP Warning:  PHP Startup: Unable to load dynamic library 'oci8.so'
    (tried:
    /usr/local/lib/php/extensions/no-debug-non-zts-20170718/oci8.so (Error
    loading shared library libresolv.so.2: No such file or directory
    (needed by /usr/local/instantclient/libclntsh.so.18.1)),
    /usr/local/lib/php/extensions/no-debug-non-zts-20170718/oci8.so.so
    (Error loading shared library
    /usr/local/lib/php/extensions/no-debug-non-zts-20170718/oci8.so.so: No
    such file or directory)) in Unknown on line 0</p>
  </blockquote>
  
  <p>I can't seem to find what package do I have to install in order to make this work. I have seen that there is a <code>libresolv.a</code> (I have also searched <a href="https://pkgs.alpinelinux.org/contents?file=libresolv*&amp;path=&amp;name=&amp;branch=edge" rel="nofollow noreferrer">here</a> and see there is no <code>libresolv.so.*</code> file in Alpine by defaut) file in my <code>/usr/lib/</code> folder so I tried sym-linking it back to Oracle folder, however that does nothing, I am still getting the same error. </p>
  
  <p>These are the packages I am installing on Docker container create:</p>
  
  <pre><code>RUN apk add --update \
      autoconf gcc g++ make libaio-dev libnsl gettext-dev automake libtool libc6-compat;
  </code></pre>