Ansible - check variable type

Question

Apparently, according to several hours of searching nobody has encountered this use-case:

Its simple - I would like to execute some ansible logic depending on variable type. Basically equivalent of e.g. instanceof(dict, var_name) but in Ansible:

- name: test
  debug:
    msg: "{{ instanceof(var_name, dict) | ternary('is a dictionary', 'is something else') }}"

Is there any way this can be done?

Answer 1

Q: "Execute some ansible logic depending on the variable type."

A: The tests including mapping work as expected. For example, the tasks below

    - set_fact:
        myvar:
          key1: value1
    - debug:
        msg: "{{ (myvar is mapping)|
                 ternary('is a dictionary', 'is something else') }}"

give

    msg: is a dictionary

---

Q: "Ansible - check variable type"

A: An option would be to discover the data type and dynamically include_tasks. For example, the tasks below

shell> cat tasks-int
- debug:
    msg: Processing integer {{ item }}

shell> cat tasks-str
- debug:
    msg: Processing string {{ item }}

shell> cat tasks-list
- debug:
    msg: Processing list {{ item }}

shell> cat tasks-dict
- debug:
    msg: Processing dictionary {{ item }}

with this playbook

- hosts: localhost
  vars:
    test:
    - 123
    - '123'
    - [a,b,c]
    - {key1: value1}
  tasks:
    - include_tasks: "tasks-{{ item|type_debug }}"
      loop: "{{ test }}"

give (abridged)

  msg: Processing integer 123

  msg: Processing string 123

  msg: Processing list ['a', 'b', 'c']

  msg: 'Processing dictionary {''key1'': ''value1''}'

If you want to simulate the switch statement create a dictionary

  case:
    int: tasks-int
    str: tasks-str
    list: tasks-list
    dict: tasks-dict
    default: tasks-default

and use it in the include

    - include_tasks: "{{ case[item|type_debug]|d(case.default) }}"
      loop: "{{ test }}"