Ansible Failed - apt lock

Environment

• On Ubuntu 16.04 / Ubuntu 14.04
• Ansible 2.3.2.0

updateApt.yml

- name: APT Update
  hosts: webservers
  become: True
  tasks:
    - name: Update apt
      apt:
        update_cache: yes

error :

fatal: [testserver2]: FAILED! => {"changed": false, "failed": true, "msg": "Failed to lock apt for exclusive operation"}

Change the playbook as:

- name: APT Update
  hosts: webservers
  become: True
  tasks:
    - name: Update apt
      apt:
        update_cache: yes
        cache_valid_time: 3600

and do this on target machine

sudo apt-get clean 
sudo apt-get update

this fixed it for me, running it on target machine