Ansible IP manipulation cheatsheet

ip_hacking_playbook.yml

---
- hosts: localhost
  gather_facts: false
  tasks:
    - name: Set constants
      ansible.builtin.set_fact:
        cidr_source: 10.0.0.0/16
        cidr_divide_bits: 4
        cidr_divide_position: 2
    
    - name: Manipulate data
      ansible.builtin.set_fact:
        cidr_last_ip: |-
          {{ cidr_source | ansible.utils.ipaddr('-2') | ansible.utils.ipv4('address') }}
        cidr_split: |-
          {{ cidr_source |
          ansible.utils.ipsubnet((cidr_source.split('/')[1] |int) + cidr_divide_bits, cidr_divide_position) }}
        cidr_split_last_ip: |-
          {{ cidr_source |
          ansible.utils.ipsubnet((cidr_source.split('/')[1] |int) + cidr_divide_bits, cidr_divide_position) |
          ansible.utils.ipaddr('-2') | ansible.utils.ipv4('address') }}
        cidr_split_first_ip: |-
          {{ cidr_source |
          ansible.utils.ipsubnet((cidr_source.split('/')[1] |int) + cidr_divide_bits, cidr_divide_position) |
          ansible.utils.ipaddr('1') | ansible.utils.ipv4('address') }}
 
    - ansible.builtin.debug:
        msg:
          - Last IP of source CIDR {{ cidr_last_ip }}
          - Divided CIDR by 4 bits and select 3rd entry {{ cidr_split }}
          - Divided CIDR by 4 bits and select 3rd entry and first IP of CIDR {{ cidr_split_first_ip }}
          - Divided CIDR by 4 bits and select 3rd entry and last IP of CIDR {{ cidr_split_last_ip }}