consul plugin does not implement if the service is blank in watchOption

[leopay]

in the registry option define

type WatchOptions struct {
// Specify a service to watch
// If blank, the watch is for all services
Service string
// Other options for implementations of the interface
// can be stored in a context
Context context.Context
}

but consul plugin seems not implement this

https://github.com/go-micro/plugins/blob/0d18e60b84eaff14af1ca32b70e3c32ec0637517/v4/registry/consul/watcher.go#L27-L55

[Davincible]

That could very well be the case.
If you have some time, feel free to implement this yourself, contributions are very welcome!