This PR enables setting of the headers block on services registered
into Nomad's service provider. Works just like the existing support
in Consul checks.
This PR hopefully fixes a race condition of our little test tcp server
that the check observer is making connections against for test cases.
The tcp listener would either startup too slow or exit too soon.
This PR adds support for specifying checks in services registered to
the built-in nomad service provider.
Currently only HTTP and TCP checks are supported, though more types
could be added later.
This PR introduces the `address` field in the `service` block so that Nomad
or Consul services can be registered with a custom `.Address.` to advertise.
The address can be an IP address or domain name. If the `address` field is
set, the `service.address_mode` must be set in `auto` mode.
The service registration wrapper handles sending requests to
backend providers without the caller needing to know this
information. This will be used within the task and alloc runner
service hooks when performing service registration activities.
This commit performs refactoring to pull out common service
registration objects into a new `client/serviceregistration`
package. This new package will form the base point for all
client specific service registration functionality.
The Consul specific implementation is not moved as it also
includes non-service registration implementations; this reduces
the blast radius of the changes as well.
