code: def add_env(self, key, value):
          
          boto.log.info('Adding env variable: %s=%s' % (key, value))
          if not os.path.exists("/etc/environment.orig"):
              self.run('cp /etc/environment /etc/environment.orig', notify=False, exit_on_error=False)
          fp = open('/etc/environment', 'a')
          fp.write('\n%s="%s"' % (key, value))
          fp.close()
          os.environ[key] = value
docs: Add an environemnt variable
          For Ubuntu, the best place is /etc/environment.  Values placed here do
          not need to be exported.