Failover DNS for Consul SD
hobson is a simply utility to provide a failover DNS strategy for Consul DNS resolution service discovery. Currently, Consul's DNS authoritative DNS server provides no mechanism to return one or a subset of DNS records for a given service. hobson will watch predefined registered Consul services and respond to DNS queries with a single A record for a given name, based on the list of service registrations. Only addresses of services with passing health checks are considered in the list of records to return, and for any given list of addresses, the same address will be returned every time.
hobson configuration is provided via YAML config file, the path of which is
referenced by the -config CLI flag:
$ ./hobson -config ./hobson.yamlThe config file expects the following elements:
- bind: The address and port to which to bind the DNS server.
- prometheus_bind: The address and port to which to bind the Prometheus metrics exposition HTTP endpoint.
- zone: The zone under which to service DNS names.
- services: A list of Consul service names to watch and return records for.
Note that hobson currently relies on the Consul Go SDK for discovering where to contact a Consul agent; see the Consul documentation for details on this behavior.
Copyright 2019 Robert Paprocki.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.