Add an item to a list dependent on a conditional in ansible

Add an item to a list dependent on a conditional in ansible

In Ansible, you can add an item to a list based on a conditional using the set_fact module. Here's how you can do it:

Example Playbook

--- - name: Add item to a list based on a condition hosts: localhost gather_facts: no vars: my_list: [] condition: true # Change this to false to see the difference tasks: - name: Add item to the list if condition is true set_fact: my_list: "{{ my_list + ['new_item'] }}" when: condition - name: Show the updated list debug: var: my_list

Explanation

  1. Define Variables:

    • my_list: Initializes an empty list.
    • condition: A boolean variable that controls whether to add the item.

  2. Add Item Based on Condition:

    • The set_fact module is used to update my_list.
    • The when statement checks the condition. If true, it adds 'new_item' to my_list.

  3. Debug Output:

    • Finally, the debug task displays the updated list.

Running the Playbook

  • If you run this playbook with condition set to true, the output will show my_list containing ['new_item'].
  • If you set condition to false, my_list will remain empty.

Additional Example: Adding Multiple Items

If you want to add multiple items based on conditions, you can do it like this:

- name: Conditionally add multiple items to a list hosts: localhost gather_facts: no vars: my_list: [] conditions: - condition1: true - condition2: false - condition3: true tasks: - name: Add items based on conditions set_fact: my_list: "{{ my_list + [item] }}" with_items: - "item1" - "item2" - "item3" when: item == "item1" and conditions[0].condition1 or item == "item2" and conditions[1].condition2 or item == "item3" and conditions[2].condition3 - name: Show the updated list debug: var: my_list

Summary

You can conditionally add items to a list in Ansible using the set_fact module and the when condition. This allows for flexible list management based on dynamic conditions.

Examples

  1. Add Item to List if Condition is True in Ansible

    - name: Add item to list if condition is true vars: my_list: [] condition_var: true new_item: "new_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: condition_var

    Description: This Ansible playbook snippet demonstrates how to add an item (new_item) to a list (my_list) only if a condition (condition_var) is true using set_fact.

  2. Add Item to List Based on Register Variable in Ansible

    - name: Run a command and add result to list if successful shell: echo "success" register: result vars: my_list: [] set_fact: my_list: "{{ my_list + ['new_value'] }}" when: result.rc == 0

    Description: This example shows how to add an item ('new_value') to a list (my_list) based on the success of a shell command (result.rc == 0) using set_fact in Ansible.

  3. Conditional Addition of Items to List in Ansible Playbook

    - name: Add item to list conditionally vars: my_list: [] condition_var: false new_item: "new_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: condition_var | bool

    Description: This Ansible playbook snippet illustrates how to conditionally add an item (new_item) to a list (my_list) based on the boolean value of condition_var using set_fact.

  4. Add Item to List if Variable Exists in Ansible

    - name: Add item to list if variable exists vars: my_list: [] condition_var: "{{ some_variable is defined }}" new_item: "new_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: condition_var

    Description: This code snippet demonstrates adding an item (new_item) to a list (my_list) in Ansible only if some_variable is defined, using set_fact and a conditional check.

  5. Add Item to List Depending on Hostname in Ansible

    - name: Add item to list based on hostname vars: my_list: [] new_item: "hostname_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: ansible_hostname == 'my_hostname'

    Description: This playbook snippet adds an item ('hostname_value') to a list (my_list) based on the hostname (ansible_hostname) matching a specific value ('my_hostname') using set_fact and a conditional.

  6. Append Item to List Depending on OS Family in Ansible

    - name: Add item to list based on OS family vars: my_list: [] new_item: "os_family_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: ansible_os_family == 'Debian'

    Description: This example showcases how to add an item ('os_family_value') to a list (my_list) in Ansible based on the OS family (ansible_os_family), specifically for Debian systems, using set_fact and a conditional.

  7. Conditionally Add Item to List in Ansible with Nested Condition

    - name: Add item to list with nested condition vars: my_list: [] condition_var1: true condition_var2: true new_item: "new_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: condition_var1 and condition_var2

    Description: This Ansible playbook snippet demonstrates adding an item (new_item) to a list (my_list) only if both condition_var1 and condition_var2 are true using set_fact.

  8. Add Item to List Based on External Condition in Ansible

    - name: Add item to list based on external condition vars: my_list: [] external_condition: "{{ external_variable }}" new_item: "new_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: external_condition

    Description: This code snippet shows how to add an item ('new_value') to a list (my_list) in Ansible based on an external condition (external_variable) using set_fact and a conditional check.

  9. Conditionally Append Item to List Depending on Inventory Group in Ansible

    - name: Add item to list based on inventory group vars: my_list: [] new_item: "group_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: inventory_hostname in groups['my_group']

    Description: This playbook snippet demonstrates adding an item ('group_value') to a list (my_list) in Ansible based on the current host's membership in an inventory group ('my_group') using set_fact and a conditional.

  10. Add Item to List Only in Certain Environments in Ansible

    - name: Add item to list in specific environments vars: my_list: [] environment: "{{ ansible_env }}" new_item: "environment_value" set_fact: my_list: "{{ my_list + [new_item] }}" when: environment == 'production'

    Description: This Ansible playbook snippet adds an item ('environment_value') to a list (my_list) based on the current environment (ansible_env), specifically adding it only in the production environment using set_fact and a conditional.

More Tags

alfresco uipageviewcontroller webclient spring-boot-test httponly rabbitmq tintcolor jupyter mootools php-5.5

More Programming Questions

More Other animals Calculators

More Math Calculators

More Electronics Circuits Calculators

More Internet Calculators