The TargetRef contains information from the object referenced
by the pod, unless the service has been set up with bare
endpoints - i.e. not pointing at pods this information
will be present.
It just makes the information that we show in the web-ui
a little more constent with that shown in kubectl
and the kuberntes dashboard.
Since we already know the name and namespace
of the service(s) we want we can just get the
correct one back from the API without filtering
the results.
* Potentialy saves a network hop
* Ability to configure LB algothim (given some work to expose an
anotation etc...)
* K8s config Watch is triggered far less often
By design k8s ingress is only designed to ballance services from within
the namespace of the ingress.
This is disscuessed a little in
https://github.com/kubernetes/kubernetes/issues/17088.
For now traefik should only reference the services in the current
namespace. For me this was a confusing change of behaviour
from the reference implimentations, as I have services
with the same name in each namespace.
If the flag kubernetes.namespaces is set...
Then we only select ingresses from that/those namespace(s)
This allows multiple instances of traefik to
independently load balance for each namespace.
This could be for logical or security reasons.
Addresses #336
