Description of problem:
MDS installation fails in ubuntu cluster using ceph-ansible

Error in Ansible:
***********************************
2017-11-22 15:44:30,943 p=22534 u=ubuntu |  task path: /usr/share/ceph-ansible/roles/ceph-common/tasks/main.yml:65
2017-11-22 15:44:30,956 p=22534 u=ubuntu |  [DEPRECATION WARNING]: always_run is deprecated. Use check_mode = no instead.. This feature will be removed in version 2.4. Deprecation warnings can be disabled by setting deprecation_warnings=False in 
ansible.cfg.
2017-11-22 15:44:30,982 p=22534 u=ubuntu |  Using module file /usr/lib/python2.7/dist-packages/ansible/modules/commands/command.py
2017-11-22 15:44:31,226 p=22534 u=ubuntu |  The full traceback is:
  File "/tmp/ansible_y6hZGQ/ansible_modlib.zip/ansible/module_utils/basic.py", line 2736, in run_command
    cmd = subprocess.Popen(args, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 711, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1343, in _execute_child
    raise child_exception

2017-11-22 15:44:31,227 p=22534 u=ubuntu |  fatal: [magna031]: FAILED! => {
    "changed": false, 
    "cmd": "ceph --version", 
    "failed": true, 
    "invocation": {
        "module_args": {
            "_raw_params": "ceph --version", 
            "_uses_shell": false, 
            "chdir": null, 
            "creates": null, 
            "executable": null, 
            "removes": null, 
            "stdin": null, 
            "warn": true
        }
    }, 
    "msg": "[Errno 2] No such file or directory", 
    "rc": 2
}



Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Configure MDS in ubuntu cluster using ubuntu ceph-ansible

Note: after installing "sudo apt-get install ceph-common" on MDS node manually ceph-ansible proceeds installation.

Logs available in this privatebin link: https://privatebin-it-iso.int.open.paas.redhat.com/?c8ac03c441ac4649#4O6zpwSF4Gblr9UipkVZNDuK8gi1iJGj7suejjLE6ok=