mirror of
https://github.com/moby/moby.git
synced 2026-01-11 18:51:37 +00:00
4538a1de0a
The eventually-consistent nature of NetworkDB means we cannot depend on events being received in the same order that they were sent. Nor can we depend on receiving events for all intermediate states. It is possible for a series of entry UPDATEs, or a DELETE followed by a CREATE with the same key, to get coalesced into a single UPDATE event on the receiving node. Watchers of NetworkDB tables therefore need to be prepared to gracefully handle arbitrary UPDATEs of a key, including those where the new value may have nothing in common with the previous value. The libnetwork controller naively handled events for endpoint_table assuming that an endpoint leave followed by a rejoin of the same endpoint would always be expressed as a DELETE event followed by a CREATE. It would handle a coalesced UPDATE as a CREATE, adding a new service binding without removing the old one. This would have various side effects, such as having the "transient state" of having multiple conflicting service bindings where more than one endpoint is assigned an IP address never settling. Modify the libnetwork controller to handle an UPDATE by removing the previous service binding then adding the new one. Signed-off-by: Cory Snider <csnider@mirantis.com>