dhparam module

dh_param

#!/usr/bin/python2

import os.path
import re

bit_matcher = re.compile(r'PKCS#3 DH Parameters: \((\d+) bit\)',re.MULTILINE)

def main():
    module = AnsibleModule(
        supports_check_mode=True,
        argument_spec = {
            'size': {'default':'512', 'choices':[str(2**x) for x in range(9,13)]},
            'path': {'required':True},
        }
    )

    size = module.params['size']
    output_file = module.params['path']

    openssl_path = module.get_bin_path('openssl', True)

    need_to_modify = True
    before=None

    if os.path.exists(output_file):
        # Check that it's the right size.

        (rc,stdout,stderr) = module.run_command(
            [openssl_path,'dhparam','-in',output_file,'-text','-noout'],
            check_rc=True,
        )
        match = bit_matcher.search(stdout)
        if match:
            before = match.group(1)
            need_to_modify = before != size

    if not need_to_modify:
        module.exit_json(changed=False, size=size)

    if not module.check_mode:
        module.run_command(
            [openssl_path,'dhparam',size,'-out',output_file],
            check_rc=True,
        )

    module.exit_json(changed=True, before=before, after=size)

from ansible.module_utils.basic import *
main()