Using Ansible Tree Callback: Save Host Events to Files Easily — Video Tutorial

Introduction Ansible, an open-source automation tool, is renowned for its ability to streamline IT tasks and configuration management. One of Ansible's powerful features is its extensible callback system, which allows users to capture and handle events triggered during playbook execution. In this article, we'll delve into the `ansible.builtin.tree` callback, introduced in Ansible-core version 2.11, and explore how it can be utilized to save host events to files. Understanding the Callback Parameters `directory` Parameter The `directory` parameter is a crucial component of the `ansible.builtin.tree` callback. It specifies the path to the directory where per-host JSON files will be saved. When using ad-hoc commands, this directory can be set using the `--tree` option. The default directory is "~/.ansible/tree." Let's break down the relevant details: - **Added in Ansible-core 2.11:** The `directory` parameter was introduced in Ansible-core version 2.11, making it available for users in more recent releases. - **INI Entry:** ```ini [callback_tree] directory = ~/.ansible/tree ``` Users can configure the `directory` parameter in the `ansible.cfg` file under the `[callback_tree]` section. - **Environment Variable:** ```bash export ANSIBLE_CALLBACK_TREE_DIR=~/.ansible/tree ``` Alternatively, the `directory` parameter can be set using the `ANSIBLE_CALLBACK_TREE_DIR` environment variable. Practical Example To illustrate the usage of the `ansible.builtin.tree` callback, consider the following example playbook and configuration: Inventory (`inventory`) ```ini localhost ansible_connection=local ``` Playbook (`ping.yml`) ```yaml --- - name: Ping module Playbook hosts: all tasks: - name: Test connection ansible.builtin.ping: ``` Ansible Configuration (`ansible.cfg`) ```ini [defaults] callbacks_enabled=ansible.builtin.tree [callback_tree] directory = ~/.ansible/tree ``` In this example: - The inventory file (`inventory`) contains a local host. - The playbook (`ping.yml`) is a simple one that pings all hosts to test the connection. - The Ansible configuration file (`ansible.cfg`) enables the `ansible.builtin.tree` callback and sets the directory for saving the host events to `~/.ansible/tree`. Execution When the playbook is executed, the `ansible.builtin.tree` callback will save host events to per-host JSON files in the specified directory (`~/.ansible/tree` in this case). This information can be invaluable for troubleshooting, auditing, and reviewing the execution flow of Ansible playbooks. By utilizing this callback, users can gain insights into the details of each host's execution, providing a structured and organized way to capture events during playbook runs. ```bash cat ~/.ansible/tree/localhost {"changed": false, "ping": "pong"} ``` Conclusion In conclusion, the `ansible.builtin.tree` callback is a powerful tool for saving host events to files, enhancing Ansible's capabilities for logging and