title: docker unzip file on run
body: <p>Here is my Dockerfiles which work, but my image is heavy.
  I would like to unzip only on start! How can I do that?
  I would like to execute <code>dockerStatScript.sh</code> just on start, and after <code>"pm2-runtime", "pm2_conf.json"</code></p>
  
  <p>I have try everything... I don't get it</p>
  
  <p>thank for your help</p>
  
  <hr>
  
  <pre><code>FROM keymetrics/pm2:12-alpine
  
  RUN apk add --no-cache --upgrade bash &amp;&amp; \
      apk add postgresql-libs libpq zip unzip tree
  
  WORKDIR /app
  
  COPY docker/dockerStatScript.sh .
  
  RUN chmod +x dockerStatScript.sh
  
  ENV NODE_ENV=production
  
  COPY app_prod/build/2.6.3/app.zip Zapp.zip
  COPY app_prod/build/2.6.3/node_modules.zip Znode_modules.zip
  COPY app_prod/build/2.6.3/config.zip Zconfig.zip
  
  RUN ["/bin/bash","dockerStatScript.sh"]
  
  CMD [ "pm2-runtime", "pm2_conf.json" ]
  
  EXPOSE 8080
  </code></pre>