title: Bash script that uses whois command gets "Servname not supported..." error on docker
body: <p>It's my first Docker image, I put there my own bash script. This script uses the <code>whois</code> command. After docker runs my script, I have some errors. Probably I made mistake on my dockerfile. Script works well on my ubuntu. 
  Should I add the <code>/etc/services</code> file to my image? </p>
  
  <p>Dockerfile:</p>
  
  <pre><code>FROM ubuntu
  ADD ./ip_info /usr/src/ip_info
  ADD ./ip_info /bin/ip_info
  RUN apt-get update &amp;&amp;  apt-get -y install whois
  RUN chmod +x /usr/src/ip_info
  CMD ["/usr/src/ip_info"]
  </code></pre>
  
  <p>error:</p>
  
  <pre><code>getaddrinfo(whois.ripe.net): Servname not supported for ai_socktype
  </code></pre>