Enable configuration of HTTP and gRPC endpoints which should be exposed by
the Connect sidecar proxy. This changeset is the first "non-magical" pass
that lays the groundwork for enabling Consul service checks for tasks
running in a network namespace because they are Connect-enabled. The changes
here provide for full configuration of the
connect {
sidecar_service {
proxy {
expose {
paths = [{
path = <exposed endpoint>
protocol = <http or grpc>
local_path_port = <local endpoint port>
listener_port = <inbound mesh port>
}, ... ]
}
}
}
stanza. Everything from `expose` and below is new, and partially implements
the precedent set by Consul:
https://www.consul.io/docs/connect/registration/service-registration.html#expose-paths-configuration-reference
Combined with a task-group level network port-mapping in the form:
port "exposeExample" { to = -1 }
it is now possible to "punch a hole" through the network namespace
to a specific HTTP or gRPC path, with the anticipated use case of creating
Consul checks on Connect enabled services.
A future PR may introduce more automagic behavior, where we can do things like
1) auto-fill the 'expose.path.local_path_port' with the default value of the
'service.port' value for task-group level connect-enabled services.
2) automatically generate a port-mapping
3) enable an 'expose.checks' flag which automatically creates exposed endpoints
for every compatible consul service check (http/grpc checks on connect
enabled services).
