How to fix ImportError: No module named cryptography?

Question

I want to auto renew certificate via certbot, but not working, got error "ImportError: No module named cryptography"

# ./certbot-auto --dry-run

Error: couldn't get currently installed version for /opt/eff.org/certbot/venv/bin/letsencrypt: Traceback (most recent call last): File "/opt/eff.org/certbot/venv/bin/letsencrypt", line 7, in from certbot.main import main File "/opt/eff.org/certbot/venv/local/lib/python2.7/dist-packages/certbot/main.py", line 10, in import josepy as jose File "/opt/eff.org/certbot/venv/local/lib/python2.7/dist-packages/josepy/init.py", line 41, in from josepy.interfaces import JSONDeSerializable File "/opt/eff.org/certbot/venv/local/lib/python2.7/dist-packages/josepy/interfaces.py", line 7, in from josepy import errors, util File "/opt/eff.org/certbot/venv/local/lib/python2.7/dist-packages/josepy/util.py", line 7, in import OpenSSL File "/opt/eff.org/certbot/venv/local/lib/python2.7/dist-packages/OpenSSL/init.py", line 8, in from OpenSSL import crypto, SSL File "/opt/eff.org/certbot/venv/local/lib/python2.7/dist-packages/OpenSSL/crypto.py", line 12, in from cryptography import x509 ImportError: No module named cryptography

I tried to install cryptography, and got this result

sudo /opt/eff.org/certbot/venv/bin/pip install cryptography

You are using pip version 9.0.1, however version 19.2.3 is available. You should consider upgrading via the 'pip install --upgrade pip' command.

Then I tried this command pip install --upgrade pip

DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support Requirement already up-to-date: pip in /usr/lib/python2.7/dist-packages/pip-19.2.3-py2.7.egg (19.2.3)

How to get cryptography installed?

Answer 1

Successfully installedI got the exact same error message after I ran certbot-auto and it upgraded to the new version.

Here's how I solve this in my case:

pip install cryptography 
cd /opt/eff.org/certbot/venv/lib64/python2.7 
mv site-packages site-packages.sav 
ln -s dist-packages/ site-packages 

It's because the letsencrypt's custom version of python is looking for the package under site-packages subfolder while it's empty in my case and the package is under dist-packages subfolder.

Note: If you see cryptography is successfully installed then no need to run 'pip install --upgrade pip' command and can disregard the warning information.