Variable with_items and hostvars

Question

I need to pass a dynamic group name info with_items so that i can access a specific fact that is ran from another host. I cannot hard code the group name

I tried to set a generic variable that is passed as 'GroupName' a few different ways. Including

with_items: "{{ groups['{{GROUPNAME}}'] }}"

   - name: Name of task
     debug:
       msg: "{{ hostvars[item]['ansible_check_mode'] }}"
     with_items: "{{ groups['GROUPNAME'] }}"

fatal: [localhost]: FAILED! => {"msg": "'dict object' has no attribute '{{ GROUPNAME }}'"}

Answer 1

update

Do not close the variable GROUPNAME in any quotes or curls

  groups[GROUPNAME]

For example, given the below inventory

shell> cat hosts
[group_A]
host_1
host_2
host_3

[group_B]
host_4
host_5

[group_C]
host_6
host_7
host_8

the play

shell> cat pb.yml
- hosts: all

  tasks:

    - debug:
        msg: "{{ item }}"
      loop: "{{ groups[GROUPNAME] }}"
      run_once: true

    - debug:
        msg: "{{ hostvars[item]['ansible_check_mode'] }}"
      loop: "{{ groups[GROUPNAME] }}"
      run_once: true

gives (abridged)

shell> ansible-playbook pb.yml -e GROUPNAME=group_B
  ...
TASK [debug] *********************************************************************************
ok: [host_1] => (item=host_4) => 
  msg: host_4
ok: [host_1] => (item=host_5) => 
  msg: host_5

TASK [debug] *********************************************************************************
ok: [host_1] => (item=host_4) => 
  msg: false
ok: [host_1] => (item=host_5) => 
  msg: false

When you run the play in the check mode you should get

shell> ansible-playbook pb.yml -e GROUPNAME=group_B --check
  ...
TASK [debug] *********************************************************************************
ok: [host_1] => (item=host_4) => 
  msg: true
ok: [host_1] => (item=host_5) => 
  msg: true

---

origin

Get the list of the hosts in the group and loop them

      vars:
        my_group: GROUPNAME
      tasks:
        - set_fact:
            my_hosts: "{{ groups|
                          dict2items|
                          selectattr('key', 'match', my_group)|
                          map(attribute='value')|
                          list|
                          flatten }}"
        - debug:
            msg: "{{ hostvars[item]['ansible_check_mode'] }}"
          loop: "{{ my_hosts }}"

(not tested)