Add two functions required by ipamapi "contract"

[bboreham]

Fixes #1984

[rade]

I notice we have

    DiscoverNew(discover *api.DiscoveryNotification) error
    DiscoverDelete(delete *api.DiscoveryNotification) error

in our (network) Driver interface. And have discoverNew and discoverDelete methods on the listener that call them. But they are not wired into the http method handling.

Cruft?

[bboreham]

Well, having them in the interface is plausible, since they were in Docker's Driver interface (refactored by moby/libnetwork@94e4e39)

Not wiring them into the http mux seems like a mistake.

Also the spelling error in their log-lines.

[bboreham]

Following moby/libnetwork#908 (comment) I guess this 'fix' is now a mistake.

[rade]

quite. let's see how that resolves itself in the end. we should probably also check/ask about the network driver api.

[mavenugo]

@bboreham sorry about the breakage. We are recommending for plugins to use https://github.com/docker/go-plugins-helpers/ for any docker plugin development. Can you please migrate to using these APIs instead of depending the libnetwork/ipamapi layer ?

[rade]

@mavenugo sure, can do!

[rade]

I am merging this as is since switching the dependencies is too much of a leap for a patch release.

I have raised #1986 to fix this properly.

[bboreham]

@mavenugo where exactly was this publicised/recommended? I missed it.

[rade]

@mavenugo AFAICT, go-plugins-helpers does not allow one to serve multiple APIs, e.g. networking and ipam, on the same listener. This is something the plugin API spec permits and we depend on. Did I miss something in my reading of the plugins-helpers code?