Amazon web services 如何在同一域名的不同服务器上安装Lets加密

Im使用aws ec2实例。我有一个使用Lets encrypt安装ssl的实例，该实例已被销毁。我用指向它的同一个域启动了一个新实例，当我尝试使用lets encrypt安装ssl时，我遇到了这个错误

   ----------------------------------------
Command "/home/ubuntu/.local/share/letsencrypt/bin/python2.7 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-rEhjk0/cryptography/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('
', '
'), __file__, 'exec'))" install --record /tmp/pip-AX0i_f-record/install-record.txt --single-version-externally-managed --compile --install-headers /home/ubuntu/.local/share/letsencrypt/include/site/python2.7/cryptography" failed with error code 1 in /tmp/pip-build-rEhjk0/cryptography
/home/ubuntu/.local/share/letsencrypt/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:120: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
You are using pip version 8.0.3, however version 8.1.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

我试过了，但没有成功

pip install --upgrade pip
pip install requests[security]
pip install pyopenssl ndg-httpsclient pyasn1