DNA Center Inventory Plugin

DNA Center Inventory Plugin allows you to utilize the network discovery capabilities of Cisco's DNA Center controller as a source of inventory for Ansible Playbooks.

DevNet Code Exchange

This repository is featured on Cisco DevNet Code Exchange.

Functionality

The DNA Center Inventory plugin will gather all groups (sites) and inventory devices from DNA Center. The hosts are associated with appropriate sites in the hierarchy.

The following host_vars are associated with the network devices:

ansible_connection : network_cli for ios and nxos devices
ansible_become_method : for ios and nxos types. (enable)
ansible_become : yes for ios and nxos types.
ansible_host : using the managementIpAddress from DNA Center - conditionally mapped based on control file dna_center.yml. (see note at the bottom)
ansible_network_os : derived from os below and required for Ansible network_cli connection plugin
os : network operating system as stored in DNA Center's softwareType
version : network operating system version as stored in DNA Center's softwareVersion

Getting Started

Follow the instructions below to install the Ansible Inventory Plugin for Cisco DNA Center on your Ansible control node.

Requirements

To utilize the inventory plugin your environment would need to include the following elements:

Ansible - (tested 2.6.2 and 2.7.2)
Cisco DNA Center - tested 1.2.8 (cisco recommended version as of 3/26/19)
Python requests module

Setup

Follow these steps to prepare your environment appropriately to consume the inventory plugin.

STEP 1. Clone or fork this repo

vagrant@ubuntu-xenial:~$ git clone https://github.com/jandiorio/ansible-dnac-inventory-plugin
Cloning into 'ansible-dnac-inventory-plugin'...
remote: Enumerating objects: 101, done.
remote: Counting objects: 100% (101/101), done.
remote: Compressing objects: 100% (47/47), done.
remote: Total 101 (delta 49), reused 101 (delta 49), pack-reused 0
Receiving objects: 100% (101/101), 32.73 KiB | 0 bytes/s, done.
Resolving deltas: 100% (49/49), done.
Checking connectivity... done.

STEP 2. Place the files in the appropriate location or update the environment variable with the location

vagrant@ubuntu-xenial:~$ cp -r ansible-dnac-inventory-plugin/inventory_plugins dna_3_legacy/

STEP 3. Enable the inventory plugin

Most Ansible inventory plugins are disabled by default so the must be enabled to be used.

The Ansible documentation will explain how to consume inventory plugins.

https://docs.ansible.com/ansible/latest/plugins/inventory.html

export ANSIBLE_INVENTORY_ENABLED=dna_center

export ANSIBLE_INVENTORY_PLUGINS=$(PWD)

The alternate way of configuring these options using the ansible.cfg file:

Add the plugin name to the list of enabled plugins. The order determines the execution order.

[inventory]
enable_plugins = host_list, script, yaml, ini, auto, dna_center

Add the path to the inventory_plugins setting in the defaults section. (use a colon : to separate multiple entries)

[defaults]
inventory_plugins = /Users/andiorij/development/dnac_inventory_plugin

https://docs.ansible.com/ansible/latest/reference_appendices/config.html

STEP 4. Update the plugin configuration file inventory_plugins/dna_center.yml

plugin: dna_center
host: 'dna-3-dnac.campus.wwtatc.local'
validate_certs: 'no'
use_dnac_mgmt_int: false
username: '{{ your_dnac_username }}'
password: '{{ your_dnac_pwd }}'

STEP 5. Execute the example below to test functionality

vagrant@ubuntu-xenial:~/dna_3_legacy$ ansible-inventory -i inventory_plugins/ --graph

/home/vagrant/.local/lib/python2.7/site-packages/urllib3/connectionpool.py:847: InsecureRequestWarning: Unverified HTTPS request is being made. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#ssl-warnings
  InsecureRequestWarning)
  
@all:
  |--@central:
  |  |--@maryland_heights:
  |  |  |--@atc56:
  |  |  |  |--dna-3-a1.campus.wwtatc.local
  |  |  |  |--dna-3-a2.campus.wwtatc.local
  |  |  |  |--dna-3-d1.campus.wwtatc.local
  |  |  |  |--dna-3-d2.campus.wwtatc.local
  |--@east:
  |--@ungrouped:
  |--@west:

Example Usage

To test if your inventory source is functioning correctly, execute the command below.

ansible-inventory --graph

ansible-inventory --list

Supporting Collateral

Ansible Inventory Plugin Overview Slides

References

https://github.com/ansible/ansible/blob/devel/lib/ansible/plugins/inventory

https://docs.ansible.com/ansible/latest/user_guide/intro_dynamic_inventory.html#dynamic-inventory

https://docs.ansible.com/ansible/latest/dev_guide/developing_inventory.html

Observed Issues

The inventory plugin builds the inventory from DNA Center includinig group mappings and some limited host variable mappings seen here:

"dna-3-d2.campus.wwtatc.local": {
                "ansible_become": "yes", 
                "ansible_become_method": "enable", 
                "ansible_connection": "network_cli", 
                "ansible_host": "192.168.19.3",
                "ansible_network_os": "ios", 
                "os": "IOS-XE", 
                "version": "16.9.1"
            }

Issue Observed - mapping of ansible_host is controlled by the plugin control file dna_center.yml. if this value is mapped, that address will be used for connection. It must be reachable. In the lab environment, this was behind a NAT and not reachable directly.

Issue Observed - if ansible_host is not mapped, the inventory_hostname must be resolvable by the ansible control mode.

Author

Jeff Andiorio - World Wide Technology

jorschul/ansible-dnac-inventory-plugin