clab-ansible-inventory

Automatic Ansible inventory generator for Containerlab topologies. Automates IP address allocation, CLNS addressing, and interface variable generation for rapid lab deployment.

Requirements

• Python 3
• PyYAML

Usage

Expects exactly one .clab.yml file in the current working directory.

View inventory:

./inventory.py

Use with Ansible:

ansible-playbook -i ./inventory.py playbook.yml

Node naming: Use <type>-<identifier> format (e.g., leaf-1, spine-2). Type is extracted from the first hyphen for inventory grouping.

What It Generates

• IPv4/IPv6 loopbacks: Sequential addresses from RFC test ranges (192.0.2.0/24, 2001:db8:8000::/33)
• Point-to-point links: /31 IPv4 and /127 IPv6 subnets
• CLNS NET addresses: Derived from IPv4 loopbacks for IS-IS
• Interface variables: Each interface includes local IPs, neighbor name, and neighbor IPs
• Ansible connection settings: Pre-configured for Arista cEOS (network_cli, credentials)

Platform Support

The addressing and variable generation works for any platform. Ansible connection settings are currently pre-configured for Arista cEOS only. To add connection settings for other platforms, edit add_lab_nodes() to map Containerlab kind values to appropriate Ansible connection variables.