https://github.com/chrislaskey/ansible-configure/blob/github/library/public_key

public_key

#!/usr/bin/python
# -*- coding: utf-8 -*-
# Just an example, how to create a ansible module ;)

from ansible.module_utils.basic import *


DOCUMENTATION = '''
---
module: public_key
short_description: Returns the SSH public key of the ansible ssh user
description:
     - Finds the ansible user's ~/.ssh/id_rsa.pub and returns the value.
version_added: "1.5"
options: {}
notes: []
requirements: []
author: Chris Laskey
'''

EXAMPLES = '''
# Example command-line invocation
ansible www.example.net -m public_key 
'''

def main():
    module = AnsibleModule(
        argument_spec = dict(
            user = dict(required=True),
        )
    )

    cmd = ["/bin/cat", "/home/ansible/.ssh/id_rsa.pub"]
    rc, out, err = module.run_command(cmd, check_rc=True)
    
    facts = {
        'public_key': out
    }

    module.exit_json(changed=False, ansible_facts=facts)


main()