Debug ansible module failures

ansible_module_debugging

1) Set ANSIBLE_KEEP_REMOTE_FILES env before executing the playbook and run the playbook with -vvvv
  for eg:
  ANSIBLE_KEEP_REMOTE_FILES=1 ansible-playbook -i inventory/ playbooks/install_contrail.yml -vvvv

2) Look for PUT message in the logs corresponding to the task...
  for eg:
  <10.87.69.8> (0, 'sftp> put /root/.ansible/tmp/ansible-local-279680i0RrK/tmpXVp8uT /root/.ansible/tmp/ansible-tmp-1559855484.58-20011953793704/AnsiballZ_docker_service.py\n'
3) On the remote host cd to the directory and unzip the file
  for eg:
  cd /root/.ansible/tmp/ansible-tmp-1559855484.58-20011953793704/
  python AnsiballZ_docker_service.py explode
4) debug_dir would have been created with __main__.py, args file and the dependent python modules
  for eg:
  root@5b12s10-node2:~/.ansible/tmp/ansible-tmp-1559855484.58-20011953793704# ls  debug_dir/
  __main__.py  ansible  args
5) You may add pdb inside the python modules or the __main__.py and run the module locally
  for eg:
  python AnsiballZ_docker_service.py execute