Swarm events

[tiborvass]

We should add swarm events to the docker events stream.

Cc @tonistiigi @vieux

[cleishm]

I'd love to see changes to the service replica count appear as events.

[cpuguy83]

@tiborvass What do you think for 1.12? I would think we should at least be able to add some events rather simply and could argue that it's needed.

[vdemeester]

@tiborvass @cpuguy83 looking into it but one question would be : should these swarm events be send to daemon /events endpoint or should it be an endpoint on its own /swarm/events (docker swarm events then) ?

[cpuguy83]

I think /events

[bitsofinfo]

Any idea on an eta for this?

[thaJeztah]

@bitsofinfo this requires changes in SwarmKit (also see the discussion on #23964), so most likely in 1.13

[thaJeztah]

with which I mean to say; not in a patch release for 1.12

[thaJeztah]

Also see moby/swarmkit#491 for the issue tracking this in SwarmKit

[tlvenn]

@thaJeztah I just want to emphasis how important this is. Any custom L7 load balancer such as Traefik or Fabio will need to tap into swarm events to react to service/task updates in order to route traffic properly.

I'm a bit worried that those projects will now implement all kind of workarounds, and by the time Swarm events are implemented, it's too late.

Ya it's already happening... :(

[thaJeztah]

Swarm events are now available as part of the docker events (on manager nodes); #32421

This feature is included in docker 17.06 and up