title: How to set envionment variables and /etc/hosts through Vagrantfile?
body: <h3>Vagrant version</h3>
  
  <p>Vagrant 1.9.7</p>
  
  <h3>Host operating system</h3>
  
  <p>Darwin bogon 16.6.0 Darwin Kernel Version 16.6.0: Fri Apr 14 16:21:16 PDT 2017; root:xnu-3789.60.24~6/RELEASE_X86_64 x86_64</p>
  
  <h3>Guest operating system</h3>
  
  <p>istributor ID:  Ubuntu</p>
  
  <p>Description:    Ubuntu 16.04.2 LTS</p>
  
  <p>Release:    16.04</p>
  
  <p>Codename:   xenial</p>
  
  <h3>Question</h3>
  
  <p>How to set envionment variables and /etc/hosts through <strong>Vagrantfile</strong>?</p>
  
  <p>In docker-composer,  I can set <strong>environment</strong> and <strong>extra_hosts</strong> </p>
  
  <p>In vagrant, how to do this?</p>