ansible playbook 多个当条件包含选项时

Question

I am creating playbook where i am taking input from user of which software version need to download as input and passing into tasks/main.yml

ansible-playbook -i inventory.txt --extra-vars 'git_version=2.7.1'

tasks/main.yml :

---
  - name: git
    include: ../../deploy/templates/git/git.yml
    when: git_version == "1.7.4" or
          git_version == "2.7.1" 

  - name: ant
    include: ../../deploy/templates/ant/ant.yml
    when: ant_version == "1.10.3" or
          ant_version == "1.10.4"

git.yml :

- name: Download Software
  get_url:
     url: "/Linux/git/{{ git_version }}/git-{{ git_version }}.tar.gz"
     dest: "{{ Tools }}"
     mode: 0755

So when i run playbook i am getting below error as syntax problem my requirement is take user input of which software he need to download and using multiple when condition with different include /import_task option to download software

TASK [Gathering Facts] ***************************************************************************************************
    ok: []

    TASK [rtt : Download Software] ********************************************************************************************
    skipping: []

    TASK [rtt : Unarchive software] *******************************************************************************************
    skipping: []

    TASK [rtt : Delete the tar file] ******************************************************************************************
    skipping: []

    TASK [rtt : Download Software] ********************************************************************************************

Answer 1

To the best of my knowledge, Ansible doesn't allow you to have when: conditions for undefined variables, with one exception:

when: variable_name is defined

For your purposes, it may be simpler to just set empty defaults, eg create defaults/main.yml with the following content:

---
ant_version: ''
git_version: ''

This allows the role to execute and tasks are only run when user's override the default variables (eg when user adds --extra-vars 'git_version=2.7.1' to playbook command).