OSError: [Errno 1] Operation not permitted in ansible - ansible

Question

From my CentOS(Ansible controller host) trying to run below playbook.
Ansible version:-
$ ansible --version
ansible 2.9.21
config file = /etc/ansible/ansible.cfg
configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
ansible python module location = /usr/lib/python3.6/site-packages/ansible
executable location = /usr/bin/ansible
python version = 3.6.8 (default, Aug 24 2020, 17:57:11) [GCC 8.3.1 20191121 (Red Hat 8.3.1-5)]
---
- hosts: pro-server
become: yes
remote_user: root
tasks:
- name: Set authorized key taken from file
ansible.posix.authorized_key:
user: root
state: present
key: "{{ lookup('file', '/root/.ssh/id_rsa.pub') }}"
It fails with below error.
$ ansible-playbook -i hosts add-ssh-key.yml
PLAY [pro-server] ****************************************************************************************************************************************
TASK [Gathering Facts] ****************************************************************************************************************************************
ok: [50.51.52.24]
TASK [Set authorized key taken from file] ********************************************************************************************************************
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: OSError: [Errno 1] Operation not permitted
fatal: [50.51.52.24]: FAILED! => {"changed": false, "msg": "Unable to make /tmp/tmp73HusP into to /root/.ssh/authorized_keys, failed final rename from /root/.ssh/.ansible_tmpy4MPxlauthorized_keys: [Errno 1] Operation not permitted"}
PLAY RECAP ****************************************************************************************************************************************************
50.51.52.24 : ok=1 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0
added the following to /etc/ansible/ansible.cfg. However still same problem persists.
allow_world_readable_tmpfiles = True
Any pointer to solve this problem will be helpful. Thank you.

Answer 1

As discussed in the comments, the problem is an 'a' attribute set on the authorized_keys file.
From man chattr:
A file with the 'a' attribute set can only be open in append mode for writing. Only the superuser or a process possessing the CAP_LINUX_IMMUTABLE capability can set or clear this attribute.
This can be fixed using the file module:
- name: make sure the 'a' attribute is removed from the authorized_keys-file
file:
path: '/root/.ssh/authorized_keys'
attributes: '-a'