title: Add dictionary file to postgresql docker container
body: <p>I am using the postgresql docker image</p>
  
  <p><a href="https://hub.docker.com/_/postgres/" rel="nofollow">https://hub.docker.com/_/postgres/</a></p>
  
  <p>To improve my full text search experience with a synonym dictionary according to <a href="http://www.postgresql.org/docs/9.5/interactive/textsearch-dictionaries.html#TEXTSEARCH-SYNONYM-DICTIONARY" rel="nofollow">http://www.postgresql.org/docs/9.5/interactive/textsearch-dictionaries.html#TEXTSEARCH-SYNONYM-DICTIONARY</a>, I have to put a file into <code>$SHAREDIR/tsearch_data</code> which happens to be folder <code>/usr/share/postgresql/9.5/tsearch_data</code> in the docker image. </p>
  
  <p>How can I do that while minimizing the set up burden for another user? (Sure I always can docker exec -it  bash to add that file manually)</p>
  
  <ol>
  <li>Create an own docker image derived from
  <a href="https://hub.docker.com/_/postgres/" rel="nofollow">https://hub.docker.com/_/postgres/</a>
  In that case, how can I add a file into that image while keeping all other setup steps as they are?</li>
  <li><p>Maybe the init script from the Postgresql-Image will be helpful for me? </p>
  
  <pre><code>If you would like to do additional initialization in an image
  derived from this one, add one or more *.sql or *.sh scripts
  under /docker-entrypoint-initdb.d 
  </code></pre>
  
  <p>(<a href="https://hub.docker.com/_/postgres/" rel="nofollow">https://hub.docker.com/_/postgres/</a>, "How to extend this image")</p></li>
  </ol>