ANSIBLE- LOOPS & CONDITION USAGE

Every programming language have loops & condition to control the flow of code execution.

Loop is used to iterate through the code based on logic and application/program requirement.

Whereas, condition is used to control the program execution.

LOOPS:

Ansible offers the loop, with_<lookup>, and until keywords to execute a task multiple times. Examples of commonly-used loops include changing ownership on several files and/or directories with the file module, creating multiple users with the user module, and repeating a polling step until a certain result is reached.

Note: loop is added in Ansible 2.5. It is not yet a full replacement for with_<lookup>, but we recommend it for most use cases.

STANDARD LOOPS:

• Iterating over simple loop

- name: Add users from given lists.
  ansible.builtin.user:
    name: "{{ item }}"
    state: present
    groups: "devops"
  loop:
     - user1
     - user2
     - user3

We define the list in a variables file, or in the ‘vars’ section of your play, then refer to the name of the list in the task.

loop: "{{ somelist }}"

- Iterating over lists of hashes.

If you have a list of hashes, you can reference subkeys in a loop. For example:

- name: Add several users
  ansible.builtin.user:
    name: "{{ item.name }}"
    state: present
    groups: "{{ item.groups }}"
  loop:
    - { name: 'user1', groups: 'devops' }
    - { name: 'user2', groups: 'aiops' }

- Iterating over dictionary.

To loop over a dict, use the dict2items:

- name: Using dict2items
  ansible.builtin.debug:
    msg: "{{ item.key }} - {{ item.value }}"
  loop: "{{ tag_data | dict2items }}"
  vars:
    tag_data:
      Environment: dev
      Application: payment

- Registering variables with a loop.

- name: Register loop output as a variable
  ansible.builtin.shell: "echo {{ item }}"
  loop:
    - "one"
    - "two"
  register: echo

WITH_ITEMS:

with_items is replaced by loop and the flatten filter.

---
- hosts: node
  tasks:
  - name: Here we are providing a simple list.
    debug:
       msg: "The given car vehicles company name is:  {{ item }}"
    with_items:
    - bmw
    - mercedes
    - tata
    - toyota
    - mazada

CONDITIONS: