apiVersion: v1
kind: ConfigMap
metadata:
  name: mariadb-peer-finder
data:
  peer-finder.py: |+
    import json
    import os
    import urllib2
    import ssl
    import socket
    import sys
    import time


    URL = ('https://kubernetes.default.svc.cluster.local/api/v1/namespaces/{namespace}'
           '/endpoints/{service_name}')
    TOKEN_FILE = '/var/run/secrets/kubernetes.io/serviceaccount/token'


    def get_service_endpoints(service_name):
       url = URL.format(namespace=os.environ['NAMESPACE'], service_name=service_name)
       try:
           token = file (TOKEN_FILE, 'r').read()
       except KeyError:
           exit("Unable to open a file with token.")
       header = {'Authorization': " Bearer {}".format(token)}
       req = urllib2.Request(url=url, headers=header)

       ctx = create_ctx()
       connection = urllib2.urlopen(req, context=ctx)
       data = connection.read()

       # parse to dict
       json_acceptable_string = data.replace("'", "\"")
       output = json.loads(json_acceptable_string)

       return output


    def get_ip_addresses(output):
       subsets = output['subsets'][0]
       if not 'addresses' in subsets:
         return []
       ip_addresses = [x['ip'] for x in subsets['addresses']]
       my_ip = get_my_ip_address()
       if my_ip in ip_addresses:
           ip_addresses.remove(my_ip)
       return ip_addresses


    def get_my_ip_address():
       s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
       s.connect(('kubernetes.default.svc.cluster.local', 0))
       return s.getsockname()[0]


    def create_ctx():
       ctx = ssl.create_default_context()
       ctx.check_hostname = False
       ctx.verify_mode = ssl.CERT_NONE
       return ctx


    def print_galera_cluster_address(service_name):
       while True:
           output = get_service_endpoints(service_name)
           if len(get_ip_addresses(output)):
               wsrep_cluster_address =  '--wsrep_cluster_address=gcomm://{}'.format(
                   ','.join(get_ip_addresses(output)))
               print wsrep_cluster_address
               break
           time.sleep(5)


    def main():
       if len(sys.argv) != 2:
           exit('peer-finder: You need to pass argument')
       service_name = sys.argv[1]
       print_galera_cluster_address(service_name)


    if __name__ == '__main__':
       main()