Category Archives: openstack

Debugging Ansible collections in Pycharm

In my day job at Red Hat I work on the os-migrate project which allows users to migrate their workloads from one Openstack deployment to another.

The project uses ansible to achieve this.

My colleague has a nice write up on os-migrate @ and you can see the official docs @

I am working on a new feature and I need to be able to debug my code changes in a nice debugger where I can step through and inspect code.

With ansible collections this isn’t as easy as regular python script or web projects as the ansible playbooks are by default run from the `~/.ansible` directory after installation using ansible-galaxy.

I use Pycharm primarily and with the help of Deepak Kothandan’s excellent Debugging Custom Ansible Modules with PyCharm post I have found a very neat way to debug the os-migrate ansible collection using the Python Debug Server built in to Pycharm and a local python virtual environment.

These are the steps I followed:

pip install pydevd-pycharm~=212.5284.44 # this will differ for your installed Pycharm version
  • Create a “Python Debug Server” Run/Debug configuration to start the debug server
a Run/Debug configuration to start the debug server
  • Start the Debug server
  • Add settrace code to the code you wish to debug
import pydevd_pycharm
pydevd_pycharm.settrace('localhost', port=40671, stdoutToServer=True, stderrToServer=True) # The port number here might differ depending on your debug configuration above
  • Build and install your ansible collection so your up to date code is used
    For os-migrate I can use our Makefile to do this
make reinstall
  • Run the code you wish to test either manually or using a different Run/Debug configuration in Pycharm. In the snippet below I am running the export networks playbook using my custom auth creds.
export OSM_DIR=/home/philroche/.ansible/collections/ansible_collections/os_migrate/os_migrate
export CUSTOM_VARIABLES="/home/philroche/Working/os-migrate/local/proche-variables.yaml"
export CUSTOM_VARIABLES_OVERRIDE="/home/philroche/Working/os-migrate/local/proche-variables-local.yaml"
export OSM_CMD="ansible-playbook -vvv -i ${OSM_DIR}/localhost_inventory.yml -e @${CUSTOM_VARIABLES} -e @${CUSTOM_VARIABLES_OVERRIDE}"
$OSM_CMD $OSM_DIR/playbooks/export_networks.yml
  • When the settrace code is reached then a debug session is started in Pycharm allowing you to step through and into your code in the Pycharm debugger interface.
Step through and into your code in the Pycharm debugger interface

I have found this very helpful in being able to quickly iterate on changes to code in an ansible collection instead of having to wait for each `ansible-playbook` run to complete.