title: set NODE_ENV variable in production via docker file
body: <p>I am trying to use below code below code in nodejs</p>
  
  <pre><code>if (process.env.NODE_ENV !== 'production')
  </code></pre>
  
  <p>I tried to set NODE_ENV variable from docker file like below.</p>
  
  <pre><code>FROM collinestes/docker-node-oracle:10-slim
  ENV NODE_ENV=production
  EXPOSE  8085
  CMD ["npm","start"]
  </code></pre>
  
  <p>If i to run my docker image it does not start and throws error. If i remove NODE_ENV all runs fine. Is it the right way to setting NODE_ENV from dockerfile?</p>