ansible.builtin.script inventory – Executes an inventory script that returns JSON

Synopsis

• The source provided must be an executable that returns Ansible inventory JSON
• The source must accept --list and --host <hostname> as arguments. --host will only be used if no _meta key is present. This is a performance optimization as the script would be called one additional time per host otherwise.

Parameters

Notes

Examples

# fmt: code

### simple bash script

   #!/usr/bin/env bash

   if [ "$1" == "--list" ]; then
   cat<<EOF
   {
     "bash_hosts": {
       "hosts": [
         "myhost.domain.com",
         "myhost2.domain.com"
       ],
       "vars": {
         "host_test": "test-value"
       }
     },
     "_meta": {
       "hostvars": {
         "myhost.domain.com": {
           "host_specific_test_var": "test-value"
         }
       }
     }
   }
   EOF
   elif [ "$1" == "--host" ]; then
     # this should not normally be called by Ansible as we return _meta above
     if [ "$2" == "myhost.domain.com" ]; then
        echo '{"_meta": {hostvars": {"myhost.domain.com": {"host_specific-test_var": "test-value"}}}}'
     else
        echo '{"_meta": {hostvars": {}}}'
     fi
   else
     echo "Invalid option: use --list or --host <hostname>"
     exit 1
   fi


### python example with ini config

    #!/usr/bin/env python
    """
    # ansible_inventory.py
    """
    import argparse
    import json
    import os.path
    import sys
    from configparser import ConfigParser
    from inventories.custom import MyInventoryAPI

    def load_config() -> ConfigParser:
        cp = ConfigParser()
        config_file = os.path.expanduser("~/.config/ansible_inventory_script.cfg")
        cp.read(config_file)
        if not cp.has_option('DEFAULT', 'namespace'):
            raise ValueError("Missing configuration option: DEFAULT -> namespace")
        return cp


    def get_api_data(namespace: str, pretty=False) -> str:
        """
        :param namespace: parameter for our custom api
        :param pretty: Human redable JSON vs machine readable
        :return: JSON string
        """
        found_data = list(MyInventoryAPI(namespace))
        hostvars = {}
        data = { '_meta': { 'hostvars': {}},}

        groups = found_data['groups'].keys()
        for group in groups:
            groups[group]['hosts'] = found_data[groups].get('host_list', [])
            if group not in data:
                data[group] = {}
            data[group]['hosts'] = found_data[groups].get('host_list', [])
            data[group]['vars'] = found_data[groups].get('info', [])
            data[group]['children'] = found_data[group].get('subgroups', [])

        for host_data in found_data['hosts']:
            for name in host_data.items():
                # turn info into vars
                data['_meta'][name] = found_data[name].get('info', {})
                # set ansible_host if possible
                if 'address' in found_data[name]:
                    data[name]['_meta']['ansible_host'] = found_data[name]['address']
        data['_meta']['hostvars'] = hostvars

        return json.dumps(data, indent=pretty)

    if __name__ == '__main__':

        arg_parser = argparse.ArgumentParser( description=__doc__, prog=__file__)
        arg_parser.add_argument('--pretty', action='store_true', default=False, help="Pretty JSON")
        mandatory_options = arg_parser.add_mutually_exclusive_group()
        mandatory_options.add_argument('--list', action='store', nargs="*", help="Get inventory JSON from our API")
        mandatory_options.add_argument('--host', action='store',
                                       help="Get variables for specific host, not used but kept for compatability")

        try:
            config = load_config()
            namespace = config.get('DEFAULT', 'namespace')

            args = arg_parser.parse_args()
            if args.host:
                print('{"_meta":{}}')
                sys.stderr.write('This script already provides _meta via --list, so this option is really ignored')
            elif len(args.list) >= 0:
                print(get_api_data(namespace, args.pretty))
            else:
                raise ValueError("Valid options are --list or --host <HOSTNAME>")

        except ValueError:
            raise