sonic-buildimage/src/sonic-config-engine/sonic-cfggen

#!/usr/bin/env python

import sys
import os.path
import argparse
import yaml
import jinja2
import netaddr
import json
from minigraph import parse_xml


def is_ipv4(value):
    if not value:
        return False
    if isinstance(value, netaddr.IPAddress):
        addr = value
    else:
        try:
            addr = netaddr.IPAddress(str(value))
        except:
            return False
    return addr.version == 4

def is_ipv6(value):
    if not value:
        return False
    if isinstance(value, netaddr.IPAddress):
        addr = value
    else:
        try:
            addr = netaddr.IPAddress(str(value))
        except:
            return False
    return addr.version == 6


def main():
    parser=argparse.ArgumentParser(description="Render configuration file from minigraph data and jinja2 template.")
    parser.add_argument("-m", "--minigraph", help="minigraph xml file")
    parser.add_argument("-y", "--yaml", help="yaml file that contains addtional variables")
    parser.add_argument("-a", "--additional-data", help="addition data, in json string")
    group = parser.add_mutually_exclusive_group()
    group.add_argument("-t", "--template", help="render the data with the template file")
    group.add_argument("-v", "--var", help="print the value of a variable")
    group.add_argument("--var-json", help="print the value of a variable, in json format")
    group.add_argument("--var-keys", help="print all keys of a map variable")
    group.add_argument("--print-data", help="print all data", action='store_true')
    args = parser.parse_args()

    data = {}

    if args.minigraph != None:
        minigraph = args.minigraph
        data.update(parse_xml(minigraph))

    if args.yaml != None:
        with open(args.yaml, 'r') as stream:
            additional_data = yaml.load(stream)      
            data.update(additional_data)

    if args.additional_data != None:
        data.update(json.loads(args.additional_data))

    if args.template != None:
        template_file = os.path.abspath(args.template)
        env = jinja2.Environment(loader=jinja2.FileSystemLoader('/'), trim_blocks=True)
        env.filters['ipv4'] = is_ipv4
        env.filters['ipv6'] = is_ipv6
        template = env.get_template(template_file)
        print template.render(data)
    
    if args.var != None:
        print data[args.var]

    if args.var_json != None:
        print json.dumps(data[args.var_json])

    if args.var_keys != None:
        for key in data[args.var_keys].keys():
          print key

    if args.print_data:
        print data

if __name__ == "__main__":
    main()