A change in EPEL broke ScyllaDB Python Script

Phenomena ^^^^^^^^^ When upgrading CentOS on a ScyllaDB node, ScyllaDB setup script, like scylla_prepare or scylla_setup fails with the following error:

.. code-block:: python

traceback (most recent call last): File "/sbin/scylla_setup", line 29, in <module> from scylla_util import * File "/usr/lib/scylla/scylla_util.py", line 31, in <module> import yaml ModuleNotFoundError: No module named 'yaml'

Problem ^^^^^^^

The source cause is a change in EPEL repository upgrade, breaking backward compatibility by moving from Python34 to Python36, and dropping PyYAML library in the process. ScyllaDB uses PyYAML in a few of its Python scripts.

Bypass ^^^^^^^

Install the python36 version of PyYAML

.. code-block:: shell

sudo yum install python36-PyYAML -y

Solution ^^^^^^^^

In future releases, we will provide a more robust solution by encapsulating Python as part of ScyllaDB Installation. More on this in the blog post The Complex Path for a Simple Portable Python Interpreter, or Snakes on a Data Plane <https://www.scylladb.com/2019/02/14/the-complex-path-for-a-simple-portable-python-interpreter-or-snakes-on-a-data-plane/>_.