introduce a handler struct, which
- enables lifting of all the handle* closures to methods
- eliminates the passing around of defaultMaxResponseSize
- reduces the number of free-floating functions
Note this doesn't test the golang resolver, where the original error
was found, as I can't find a way to point the golang resolver at a
custom dns server during a test. It does check that a compressed
response from an upstream server is correctly handled.
- 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.
Tom Wilkie