How can I manage groups in inventory? - ansible

Question

I have a common playbook (task) but in my last task I want to do an action on a group of hosts and when it is finished, do the same action on another group (for my test I simply empty a folder):
- name: test clean folder on hosts
ansible.builtin.file:
path: /testJO
when: inventory_hostname in groups['c_hosts']
- name: test clean folder on master
ansible.builtin.file:
path: /testJO
when: inventory_hostname in groups['master’]
I have issue with my inventory file :
/root/ansible_Folder/inventories/inventories.yml :
all:
hosts:
children:
master:
hosts:
dem-master:
c_hosts:
hosts:
dem-host:
Who knows how I can manage my inventories file please?
EDIT :
I tried your solution which seems to me coherent but i have this error message :
ERROR! conflicting action statements: hosts, tasks
The error appears to be in '/root/ansible-cortex-lab/playbooks/roles/cortex/tasks/main.yml': line 1, column 3, but may
be elsewhere in the file depending on the exact syntax problem.
The offending line appears to be:
- hosts: c_hosts
^ here
I just copy past both config file you gave to me.
Do you know why I have this behaviour please ?

Answer 1

Separate the plays, e.g.
- hosts: c_hosts
tasks:
- name: test remove folder
ansible.builtin.file:
path: /testJO
state: absent
- name: test create folder
ansible.builtin.file:
path: /testJO
state: directory
- hosts: master
tasks:
- name: test remove folder
ansible.builtin.file:
path: /testJO
state: absent
- name: test create folder
ansible.builtin.file:
path: /testJO
state: directory
The module file can't simply clean a folder. Instead, remove a folder and create it again.
To fix the inventory, remove the 2nd line hosts:. See Inventory basics: formats, hosts, and groups
all:
children:
master:
hosts:
dem-master:
c_hosts:
hosts:
dem-host: