Ansible을 사용한 네트워크 구성

Bash and Python scripts describe how to do something step by step. Ansible describes the desired state and converges hosts toward it.

This is idempotent: running the same playbook twice leaves the system in the same correct state.

Ansible needs no agent on managed hosts. It connects over SSH (or network device APIs) and pushes changes, making it easy to adopt across a fleet.

The inventory lists the hosts you manage, grouped logically. Below is a simple INI inventory.

For quick one-off tasks, run a module directly without a playbook. This pings all hosts in a group.

A playbook is a YAML file describing tasks. Each task invokes a module with parameters.

Variables parameterize playbooks. The template module renders Jinja2 files, perfect for generating per-device config from one source of truth.

Ansible ships vendor collections (e.g. cisco.ios, arista.eos) that speak each platform's CLI or API to push configuration.

Handlers run only when notified by a changed task — ideal for restarting a service or saving a device config exactly once after changes.

Run any playbook with --check to preview changes without applying them — a safe way to validate before touching production.

Roles package tasks, templates, and variables into reusable units. A base-network role can be applied to every device for consistent baseline config.

Never store passwords in plaintext. ansible-vault encrypts sensitive variables, keeping credentials safe in version control.

You can now automate declaratively with Ansible:

• Agentless, idempotent state management
• Inventories, playbooks, and variables
• Vendor network modules and Jinja2 templates
• Handlers, roles, and --check dry runs
• Encrypt secrets with ansible-vault

This extends your Bash, Python, and REST API automation lessons to fleet scale.