Ansible Facts Playbook

Everything begins and starts with facts

More about Modules

  • Modules do the actual work in Ansible, they are what gets executed in each playbook task.

    • Typically written in Python (but not limited to it)

    • Modules can be idempotent

    • Modules take user input in the form of parameters

Network modules

  • Ansible modules for network automation typically references the vendor OS followed by the module name.

    • namename.collection.module

    • namespace.collection.facts

    • namespace.collection.command

    • namespace.collection.config

    • namespace.collection.resource

    For example:

    • Arista EOS = arista.eos.

    • Cisco IOS/IOS-XE = cisco.ios.

    • Juniper Junos = junipsnetworks.junos.

What are facts?

  • Fact modules are unique per platform. For Cisco IOS-XE you would use cisco.ios.facts, for Juniper Junos you would use junipernetworks.junos.facts and so on and so forth.

    picture of facts

  • Structured data, the Ansible way

    picture of transform facts
    Ansible trasnforms pics

Lets get started

That is the end of of your lab briefing!

Step 1 - Creating the play

Ansible Playbooks are YAML files. YAML is a structured encoding format that is also extremely human readable (unlike it’s subset - the JSON format)

  • Click on the code-server tab

  • Create a new file in Visual Studio code. Click on the File Top Nav bar then click New File

  • For simplicity please name the playbook: facts.yml

  • Enter the following play definition into facts.yml:

    ---
- name: gather information from routers
  hosts: cisco
  gather_facts: no

    Here is an explanation of each line:

    • The first line, --- indicates that this is a YAML file.

    • The - name: keyword is an optional description for this particular Ansible Playbook.

    • The hosts: keyword means this playbook against the group cisco defined in the inventory file.

    • The gather_facts: no turns of auto-fact gathering, we are going to use a module instead.

Step 2 - Create the facts task

  • Append the following to your playbook:

      tasks:
    - name: gather router facts
      cisco.ios.facts:
    A play is a list of tasks. Modules are pre-written code that perform the task.

Step 3 - Executing the playbook

  • Click on the terminal tab. Execute the Ansible Playbook by running ansible-navigator:

    ansible-navigator run facts.yml

  • This will open an interactive session while the playbook interacts.

    • To zoom into the playbook output we can press 0 which will show us a host-centric view. Since there is only one host, there is just one option.

    • To see the verbose output of cisco press 0 one more time to zoom into the module return values.

    • You can scroll down to view any facts that were collected from the Cisco network device.

Complete

You have completed challenge 2!