This change makes few compromises:
* Looks up the devices associated with tasks at look up time. Given
that `nomad alloc status` is called rarely generally (compared to stats
telemetry and general job reporting), it seems fine. However, the
lookup overhead grows bounded by number of `tasks x total-host-devices`,
which can be significant.
* `client.Client` performs the task devices->statistics lookup. It
passes self to alloc/task runners so they can look up the device statistics
allocated to them.
* Currently alloc/task runners are responsible for constructing the
entire RPC response for stats
* The alternatives for making task runners device statistics aware
don't seem appealing (e.g. having task runners contain reference to hostStats)
* On the alloc aggregation resource usage, I did a naive merging of task device statistics.
* Personally, I question the value of such aggregation, compared to
costs of struct duplication and bloating the response - but opted to be
consistent in the API.
* With naive concatination, device instances from a single device group used by separate tasks in the alloc, would be aggregated in two separate device group statistics.
Fixes#3380
Adds address_mode to checks (but no auto) and allows services and checks
to set literal port numbers when using address_mode=driver.
This allows SDNs, overlays, etc to advertise internal and host addresses
as well as do checks against either.
In testing realized that Resources night not be present at all. Testing this case caused panic. Added in a means to collect clean defaults in that case.
The current code would merge the job with the output of MinResources causing the nil to be replaced with MemoryMB=helper.IntToPtr(10). When later `Canonicalize`d, the 10 would cause the default of 300 not to be applied. Running `Canonicalize` on the task itself guarantees that CPU, MemoryMB, and IOPS is set, so we can remove the Merge withMinResources.
This PR fixes an issue in which we would merge an update stanza from the
job into the task groups even if it was empty. This broke round
tripping a job (reading from the api and resubmitting as JSON)
Fixes https://github.com/hashicorp/nomad/issues/3132
