capslocksucks.yml

---
- hosts: localhost
  vars:
    - kb_key: "com.apple.keyboard.modifiermapping"
    - kb_map_dest: "HIDKeyboardModifierMappingDst"
    - kb_map_src: "HIDKeyboardModifierMappingSrc"
  tasks:
    - shell: >
        ioreg -p IOUSB -c IOUSBDevice |
        grep -e class -e idVendor -e idProduct |
        grep -A2 Internal | grep idVendor | awk -F'= '  '{print $2}'
      register: id_vendor

    - shell: >
        ioreg -p IOUSB -c IOUSBDevice |
        grep -e class -e idVendor -e idProduct |
        grep -A2 Internal | grep idProduct | awk -F'= '  '{print $2}'
      register: id_product

    - name: "Read builtin keyboard map for caps lock setup"
      shell: >
        defaults -currentHost read -g
        {{ kb_key }}.{{ id_vendor.stdout }}-{{ id_product.stdout }}-0
      register: current_layout

    - name: "Ensure builtin keyboard maps caps lock to control"
      shell: >
        defaults -currentHost write -g
        {{ kb_key }}.{{ id_vendor.stdout }}-{{ id_product.stdout }}-0
        -array '({{{ kb_map_dest }}=2;{{ kb_map_src }}=0;})'
      when: current_layout.stdout != >
        '(
                (
                        {
                    HIDKeyboardModifierMappingDst = 2;
                    HIDKeyboardModifierMappingSrc = 0;
                }
            )
        )'

The failure I get when running:
PLAY [localhost] **************************************************************

GATHERING FACTS ***************************************************************
ok: [localhost]

TASK: [shell ioreg -p IOUSB -c IOUSBDevice | grep -e class -e idVendor -e idProduct | grep -A2 Internal | grep idVendor | awk -F'= ' '{print $2}'
] ***
changed: [localhost]

TASK: [shell ioreg -p IOUSB -c IOUSBDevice | grep -e class -e idVendor -e idProduct | grep -A2 Internal | grep idProduct | awk -F'= ' '{print $2}'
] ***
changed: [localhost]

TASK: [Read builtin keyboard map for caps lock setup] *************************
changed: [localhost]

TASK: [Ensure builtin keyboard maps caps lock to control] *********************
fatal: [localhost] => error while evaluating conditional: current_layout.stdout != > '( ( { HIDKeyboardModifierMappingDst = 2; HIDKeyboardModifierMappingSrc = 0; } ) )'

FATAL: all hosts have already failed -- aborting