docs: def is_ssh_available(host, opts, print_ssh_output=True):
      """
      Check if SSH is available on a host.
      """
      s = subprocess.Popen(
          ssh_command(opts) + ['-t', '-t', '-o', 'ConnectTimeout=3',
                               '%s@%s' % (opts.user, host), stringify_command('true')],
          stdout=subprocess.PIPE,
          stderr=subprocess.STDOUT  # we pipe stderr through stdout to preserve output order
      )
      cmd_output = s.communicate()[0]  # [1] is stderr, which we redirected to stdout
  
      if s.returncode != 0 and print_ssh_output:
          # extra leading newline is for spacing in wait_for_cluster_state()
          print(textwrap.dedent("""\n
              Warning: SSH connection error. (This could be temporary.)
              Host: {h}
              SSH return code: {r}
              SSH output: {o}
          """).format(
              h=host,
              r=s.returncode,
              o=cmd_output.strip()
          ))
  
      return s.returncode == 0