#!/usr/bin/python

import json
import urllib2
import sys
import re

URL = 'http://169.254.169.254/latest/user-data'

try:
    data = json.load(urllib2.urlopen(URL))
except:
    print >> sys.stderr, 'Was not able to connect to the Amazon API'
    sys.exit(2)

# Python doesn't like a list of 1
tags = []
tags.append(data['role'])

consul_settings = {
                        'data_dir': '/opt/consul/data',
                        'client_addr': '0.0.0.0',
                        'datacenter': data['domain'],
                        'domain': data['domain'],
                        'log_level': "INFO",
                        'enable_script_checks': True,
                        'service': [
                                        { 'name': data['role'], 'tags': tags, 'checks': [{'args': ['/bin/true'], 'interval': '2s'}] }
                                        ]

}

if data['consul_master'] == '127.0.0.1':
    consul_settings['bootstrap_expect'] = 1
else:
    consul_settings['retry_join'] = [data['consul_master']]

if re.match('consul', data['role']) is not None:
    consul_settings['server'] = True
    consul_settings['ui'] = True

main_config = open("/opt/consul/etc/config.json", "w")
main_config.write(json.dumps(consul_settings))
main_config.close()