Service without labels returns null, not {}

[thaJeztah]

if no labels are set on a service, Spec.Labels is null, not an empty map/object;

$ docker service create --name nolabels nginx:alpine
$ docker service inspect --format '{{ json .Spec.Labels}}' nolabels
null

This is inconsistent with containers, where it's always a map/object;

$ docker run --name nolabels busybox sh
$ docker inspect --format '{{json .Config.Labels }}' nolabels
{}

I think we should fix that, to keep consistency in our UX.

[thaJeztah]

/cc @tiborvass

[vdemeester]

Agreeing on the inconsistency, I'll take a look.
#dibs 👼

[thaJeztah]

@vdemeester Thanks! I didn't check other properties (env-vars, etc), so those may need a change as well. Also didn't compare the API between "containers" and "services"

[thaJeztah]

ping @vdemeester just found this one, did we ever change this?

[adshmh]

#dibs

A few other types also behave the same way, e.g.:

$ docker node inspect --format '{{ json .Spec.Labels}}' self
null