如何在ansible的vars文件中使用if条件

Question

Is it possible to do something like this in anisble vars file

env: "{{ lookup('env','MY_ENV') }}"    
user: tom if {{ env }} else mike

Answer 1

Here is an answer to your question, I think you cannot use env as variable because it's reserved word in ansible:

---
- hosts: all 
  gather_facts: no
  vars:
    ENV: "dev"
  tasks:
    - debug:
        msg: "{%- if ENV == 'dev' -%} tom {%- else -%} mike {%- endif -%}"

Result when the value of ENV is dev :

% ansible-playbook -i "localhost," test.yml -c local

PLAY [all] *********************************************************************

TASK [debug] *******************************************************************
ok: [localhost] => {
    "msg": "tom"
}

PLAY RECAP *********************************************************************
localhost                  : ok=1    changed=0    unreachable=0    failed=0

Result when the value of ENV is something else:

% ansible-playbook -i "localhost," test.yml -c local

PLAY [all] *********************************************************************

TASK [debug] *******************************************************************
ok: [localhost] => {
    "msg": "mike"
}

PLAY RECAP *********************************************************************
localhost                  : ok=1    changed=0    unreachable=0    failed=0

Hope that help you

Answer 2

One way is to use another lookup into a json file containing the user-env mappings. Eg:

user_envs.json:

{
    "dev": "tom",
    "prod": "mike"
}

lookup:

{{ (lookup('file', 'user_envs.json') | from_json).get('dev') }}

Don't have an env to try it now but give it a shot!