Service by label
In general when configuring a Traefik provider, a service assigned to one (or several) router(s) must be defined as well for the routing to be functional.
There are, however, exceptions when using label-based configurations:
- If a label defines a router (e.g. through a router Rule) and a label defines a service (e.g. implicitly through a loadbalancer server port value), but the router does not specify any service, then that service is automatically assigned to the router.
- If a label defines a router (e.g. through a router Rule) but no service is defined, then a service is automatically created and assigned to the router.
As one would expect, in either of these cases, if in addition a service is specified for the router, then that service is the one assigned, regardless of whether it actually is defined or whatever else other services are defined.