This PR adds support for configuring `proxy.upstreams[].config` for
Consul Connect upstreams. This is an opaque config value to Nomad -
the data is passed directly to Consul and is unknown to Nomad.
When configuring Consul Service Mesh, it's sometimes necessary to
provide dynamic value that are only known to Nomad at runtime. By
interpolating configuration values (in addition to configuration keys),
user are able to pass these dynamic values to Consul from their Nomad
jobs.
This PR enables job submitters to use interpolation in the connect
block of jobs making use of consul connect. Before, only the name of
the connect service would be interpolated, and only for a few select
identifiers related to the job itself (#6853). Now, all connect fields
can be interpolated using the full spectrum of runtime parameters.
Note that the service name is interpolated at job-submission time,
and cannot make use of values known only at runtime.
Fixes#7221
* client: improve group service stanza interpolation and check_restart support
Interpolation can now be done on group service stanzas. Note that some task runtime specific information
that was previously available when the service was registered poststart of a task is no longer available.
The check_restart stanza for checks defined on group services will now properly restart the allocation upon
check failures if configured.
