Certbot — No module named ‘_cffi_backend’

Today, one of the server manage by me has failed to auto renew the https certificate.

Btw, i’m using certificate from R3 by Let’s Encrypt. When i tried to manual renew using sudo certbot renew, i got this error message (see below for the error message).

ubuntu@ip-172-26-4-157:~$ sudo certbot renew
Traceback (most recent call last):
  File "/usr/bin/certbot", line 11, in <module>
    load_entry_point('certbot==0.31.0', 'console_scripts', 'certbot')()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 542, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2569, in load_entry_point
    return ep.load()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2229, in load
    return self.resolve()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2235, in resolve
    module = __import__(self.module_name, fromlist=['__name__'], level=0)
  File "/usr/lib/python3/dist-packages/certbot/main.py", line 10, in <module>
    import josepy as jose
  File "/usr/lib/python3/dist-packages/josepy/__init__.py", line 44, in <module>
    from josepy.interfaces import JSONDeSerializable
  File "/usr/lib/python3/dist-packages/josepy/interfaces.py", line 8, in <module>
    from josepy import errors, util
  File "/usr/lib/python3/dist-packages/josepy/util.py", line 4, in <module>
    import OpenSSL
  File "/usr/lib/python3/dist-packages/OpenSSL/__init__.py", line 8, in <module>
    from OpenSSL import crypto, SSL
  File "/usr/lib/python3/dist-packages/OpenSSL/crypto.py", line 12, in <module>
    from cryptography import x509
  File "/usr/lib/python3/dist-packages/cryptography/x509/__init__.py", line 9, in <module>
    from cryptography.x509.base import (
  File "/usr/lib/python3/dist-packages/cryptography/x509/base.py", line 16, in <module>
    from cryptography.x509.extensions import Extension, ExtensionType
  File "/usr/lib/python3/dist-packages/cryptography/x509/extensions.py", line 18, in <module>
    from cryptography.hazmat.primitives import constant_time, serialization
  File "/usr/lib/python3/dist-packages/cryptography/hazmat/primitives/constant_time.py", line 9, in <module>
    from cryptography.hazmat.bindings._constant_time import lib
ModuleNotFoundError: No module named '_cffi_backend'

On the Stack Overflow, someone suggested installing the cffi package using python pip and i tried to install the package, but i got the error message again. No problem for me, this is challenge when tried to solve the issue but got a new issue. wkwk.

See below for a new error message.

ubuntu@ip-172-26-4-157:~$ pip3 install -U cffi
Exception:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 209, in main
    status = self.run(options, args)
  File "/usr/lib/python3/dist-packages/pip/commands/install.py", line 267, in run
    with self._build_session(options) as session:
  File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 66, in _build_session
    session = PipSession(
  File "/usr/lib/python3/dist-packages/pip/download.py", line 321, in __init__
    self.headers["User-Agent"] = user_agent()
  File "/usr/lib/python3/dist-packages/pip/download.py", line 93, in user_agent
    zip(["name", "version", "id"], platform.linux_distribution()),
AttributeError: module 'platform' has no attribute 'linux_distribution'
Traceback (most recent call last):
  File "/usr/bin/pip3", line 11, in <module>
    sys.exit(main())
  File "/usr/lib/python3/dist-packages/pip/__init__.py", line 217, in main
    return command.main(cmd_args)
  File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 242, in main
    with self._build_session(
  File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 66, in _build_session
    session = PipSession(
  File "/usr/lib/python3/dist-packages/pip/download.py", line 321, in __init__
    self.headers["User-Agent"] = user_agent()
  File "/usr/lib/python3/dist-packages/pip/download.py", line 93, in user_agent
    zip(["name", "version", "id"], platform.linux_distribution()),
AttributeError: module 'platform' has no attribute 'linux_distribution'

I think python3 pip on the server is crash. So i delete the python3 pip and re-install it using command curl -L get-pip.io | python3. After that, i tried again to install cffi package and successfull install the package.

ubuntu@ip-172-26-4-157:~$ pip3 install -U cffi
Defaulting to user installation because normal site-packages is not writeable
Requirement already satisfied: cffi in /usr/lib/python3/dist-packages (1.10.0)
Collecting cffi
  Downloading cffi-1.14.5-cp38-cp38-manylinux1_x86_64.whl (411 kB)
     |████████████████████████████████| 411 kB 33.2 MB/s
Requirement already satisfied: pycparser in /usr/lib/python3/dist-packages (from cffi) (2.14)
Installing collected packages: cffi
Successfully installed cffi-1.14.5

Originally published at https://sibunglon.com on July 10, 2021.