- Nameserver holds a sorted list of (hostname, peer, container id, ip) tuples.
- Entries are gossiped using topology gossip / broadcast - only new/updated entries
are propogated as expected.
- Entries for a given peer are removed when the connection to the peer is lost.
- Entries are tombstoned when containers die. Tombstones are kept for 10mins,
as they do not need to survive partition, only gossip propagation delay.
We erroneously assumed that `docker start` returned the full container
id. It doesn't and as a result we populated DNS with records with ids
other than full container ids. And that's also what we told IPAM. As a
result, DNS and IPAM didn't clean up after the container's death,
resulting in stale DNS entries and leaked IPs.
Fixes#881.
Bryan Boreham