surok/surok/discovery.py
2016-08-10 11:55:18 +03:00

43 lines
1.2 KiB
Python

import dns.resolver
import dns.query
from dns.exception import DNSException
# Resolve service from mesos-dns SRV record
# return dict {"servicename": [{"name": "service.f.q.d.n.", "port": 9999}]}
def resolve(app, conf):
hosts = {}
services = app['services']
domain = conf['domain']
group = None
if app['env'].get('SUROK_DISCOVERY_GROUP') is not None:
group = app['env']['SUROK_DISCOVERY_GROUP']
for service in services:
hosts[service['name']] = []
# Check group configuration
if group is not None:
pass
else:
# Load group from service config
# /etc/surok/conf.d/service_conf.json
group = service['group']
try:
fqdn = '_' + service['name'] + '.' + group + '._tcp.' + domain
query = dns.resolver.query(fqdn, 'SRV')
query.lifetime = 1.0
for rdata in query:
info = str(rdata).split()
server = {'name': info[3], 'port': info[2]}
hosts[service['name']].append(server)
except DNSException:
print("Could not resolve " +
service['name'] + '.' +
group + '._tcp.' + domain)
return hosts