Import Error from cyptography.hazmat.bindings._constant_time import lib

Question

So I\'m trying to create an aws lambda function, to log in to an instance and do some stuff. And the script works fine outside of lambda, but when I package it using the sam

Answer 1

The zip commands in that tutorial are missing a parameter. I ran into this exact problem today with pysftp, which is built on paramiko. libffi-72499c49.so.6.0.4 is in a hidden dot directory inside lib64/python2.7/site-packages/.libs_cffi_backend. Depending on how you zipped up the dependencies in your virtualenv, you may have inadvertantly excluded this directory.

1. First, make sure libffi-devel and openssl-devel are installed on your Amazon Linux instance, otherwise the cryptography module may not be compiling correctly.

   sudo yum install libffi-devel openssl-devel
   

If those packages were not installed before, delete and rebuild your virtualenv.

2. Make sure that when you are zipping up your site-packages that you use '.' instead of '*', otherwise you will not be including files and directories that are hidden because their names begin with a period.

   cd path/to/my/helloworld-env/lib/python2.7/site-packages
   zip -r9 path/to/zip/worker_function.zip .
   cd path/to/my/helloworld-env/lib64/python2.7/site-packages
   zip -r9 path/to/zip/worker_function.zip .