Deploying Custom Device Configurations

netlab config uses an internal Ansible playbook (netsim/ansible/config.ansible) to deploy custom device configurations generated from the supplied Jinja2 template(s) to lab devices.


netlab config command does not need a topology file (so you don’t have to specify one even if you’re using a non-default topology name). It’s just a thin wrapper around an Ansible playbook which uses Ansible inventory created by netlab create or netlab up command.


usage: netlab config [-h] [-v] template

Deploy custom configuration template

positional arguments:
  template       Configuration template (or a family of templates)

optional arguments:
  -h, --help     show this help message and exit
  -v, --verbose  Verbose logging

All other arguments are passed directly to ansible-playbook

Selecting Configuration Template

When the configuration template specified in netlab config command is not a Jinja2 template, the command tries to find the configuration template for individual lab devices using node name, netlab_device_type, and ansible_network_os Ansible variables, allowing you to create a set of templates to deploy the same functionality to lab devices running different network operating systems.

See Custom Deployment Templates and Finding Custom Configuration Templates for more details.

Limiting the Scope of Configuration Deployments

All unrecognized parameters are passed to internal config.ansible Ansible playbook. You can use ansible-playbook CLI parameters to modify the configuration deployment, for example:

  • -l parameter to deploy device configurations on a subset of devices.

  • -C parameter to run the Ansible playbook in dry-run mode.

Debugging Device Configurations

To display device configurations from within the Ansible playbook without deploying them, use -v --tags test parameters after the template name.

The -v flag will trigger debugging printout, and the bogus test flag will skip the actual configuration deployment.