Event-Driven automation for Ansible and a Kafka integration example

Alongside the general availability of the Ansible Automation Platform 2.3, Red Hat announced the Event Driven technology, a community project released by Red Hat.

Event-Driven Ansible, is now available as a developer preview.

Red Hat also announced plans to integrate Event-Driven Ansible into AAP (Ansible Automation Platform) as an integrated component in 2023. For more information on why event-driven automation matters for IT Teams, refer to:

https://www.ansible.com/use-cases/event-driven-automation

Event-Driven Ansible is designed for:

• Process events from external sources, like tools from partners.
• Determine the desired response to the event.
• Execute automated actions to address or remediate the event.

Event-Driven connects sources of events with desired actions using rulebooks.

Rulebooks define the event source and determine the action to take when a specific condition is detected. The detection is defined with a familiar “if-this-then-that” instruction, and the action can be like running a playbook or directly executing a module.

Like traditional Ansible Playbooks, rulebooks are also created in YAML.

The three main components of the rulebooks are:

• Source: the sources of events come from source plugins. These plugins define where to listen for events.
• Condition: the conditional statements in the rulebook allow matching criteria on which is necessary to have a response.
• Action: The action is the response once the condition has been met from the event source as trigger remediation, log a ticket for observation, or generate other events as the response.

In the example below, we will monitor kafka messages on a topic and respond to a specific one.

You can access and try this simple guided lab at the following link:

https://www.ansible.com/products/ansible-training#event-driven-automation

The figure shows the content of a rulebook called “kafka-example.yml”:

We can verify that the source is the kafka plugin. The source is pointing to a kafka host called “broker” and to a topic called “eda-topic”.

The rule is looking for a message on that topic that matches the text “Ansible is cool” and the action is running the “say-what.yml” playbook.

So, the first step is to start the “ansible-rulebook” against the kafka rulebook with the following command:

ansible-rulebook –rules kafka-example.yml -i inventory.yml –verbose

After that, the “ansible-rulebook” is listening to the source:

Now, we can send a message using the running kafka client that will be a match for the conditions in the active rulebook:

{"message":"Ansible is cool"}

We can see that the message has been read from the topic, and the playbook is executed:

I hope this information was helpful.

References:

https://www.ansible.com/use-cases/event-driven-automation

https://www.ansible.com/blog/introducing-event-driven-ansible?hsLang=en-us

https://www.ansible.com/blog/getting-started-with-event-driven-ansible

https://github.com/ansible/ansible-rulebook

https://access.redhat.com/support/offerings/devpreview

https://www.redhat.com/en/topics/integration/what-is-apache-kafka