synapse

https://www.haproxy.com/blog/dns-service-discovery-haproxy/ (which is a link on the OP) says TTL on SRV records "is ignored by HAProxy as HAProxy maintains its own expiry data which is defined in the configuration". Is this true for A records too? If so, neither haproxy nor nginx expire cached A records. Nginx Plus does, and a few nginx plugins do, however. https://github.com/airbnb/synapse is a process that polls DNS, and updates haproxy config accordingly and SIGHUPs haproxy I've used synapse to solve this issue, but it's a moving piece I'd rather not have involved.

Disclaimer: I help maintain Synapse. I highly recommend this tool. Yelp has used it in production for years to manage a fairly large PaaS (hundreds of services, thousands of containers, constant churn); it's proven quite flexible and resilient. Synapse is available on github [0], and we've open sourced our automation used to create a highly available service router using Synapse as well [1][2]. [0] https://github.com/airbnb/synapse [1] https://github.com/Yelp/synapse-tools/tree/master/src/synaps... [2] http://paasta.readthedocs.io/en/latest/yelpsoa_configs.html#...