add/remove DNS entries on network connect/disconnect

[bboreham]

Currently, weaveplugin listens for container started events, to know when to add a container name to DNS. We do some poking around in the API to see whether the container is actually connected to the weave network.

This approach is rather indirect, and misses docker network connect / disconnect.

In 1.10, Docker introduces network events, which give a much more direct way to achieve the requirement.

Given #813, we may be justified in requiring minimum Docker 1.10 when using the plugin.

[bboreham]

Also, as noted on IRC, users can use --alias to give additional names in docker network connect, similar to #1975.

[bboreham]

Post #2374 we should also do the arp configuration on docker network connect

[dlmiddlecote]

I'm going to work on this.

[bboreham]

Thanks @dlmiddlecote - if you have any questions please ask here or in the Slack