CICD pipeline to configure BGP between four cisco IOS devices

This pipeline executes on a Self Managend GitLab instance and a gitlab-runner executing in shell mode.

CICD workflow

Before making any configuration changes (only IP and BGP confgiuration covered in this example), a new issue and a branch needs to be created in GitLab.

Each time a commit is made to the Gitlab branch, device configs are generated and the generated configs are evaluated against defined assertions.

• The device configs are generated using jinja2 templates in the templates folder and input data in the host_vars folder. The code for configuration generation is in the generate_config.yaml playbook.
• A batfish snapshot is initialized from the generated configuration and an assertion is made to validate that there are no incompatabile bgp sessions. The code to do this is in the batfish_test.yaml playbook.

Once these two stages are successful, a merge request needs to be placed to merge with the master branch. Upon approval, the third and final stage of the pipeline is initiated which configures the actual network devices. The code to do this is in the configure_devices.yaml.

The exact sequence of commands to generate configurations, run assertions and deploy the configuration are in template.gitlab-ci.yml file, which is uploaded to the Gitlab repository as its pipeline file (.gitlab-ci.yml) when the repository is initialized.

Sample Output

Generate Configuration

Batfish Test

Configure Device

Note

In a real world scenario I would use napalm_install_config to do a full config replace. Due the limitation of using virtual Cisco IOS devices in EVE-NG and a lack of flash: memory on them, in the above example I have used ios_config.