code: def write_proc_sh(self):
          
          print("Writing proc.sh")
          context = {
              'tmp': '/tmp',
              'home': '/app',
              'settings': '/settings.yaml',
              'envsh': '/env.sh',
              'port': self.config.port,
              'cmd': self.get_cmd(),
          }
          sh_path = os.path.join(get_container_path(self.config), 'proc.sh')
          rendered = get_template('proc.sh') % context
          with open(sh_path, 'w') as f:
              f.write(rendered)
          st = os.stat(sh_path)
          os.chmod(
              sh_path, st.st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
docs: Write the script that is the first thing called inside the
          container.  It sets env vars and then calls the real program.