IOPS have been modelled as a resource since Nomad 0.1 but has never
actually been detected and there is no plan in the short term to add
detection. This is because IOPS is a bit simplistic of a unit to define
the performance requirements from the underlying storage system. In its
current state it adds unnecessary confusion and can be removed without
impacting any users. This PR leaves IOPS defined at the jobspec parsing
level and in the api/ resources since these are the two public uses of
the field. These should be considered deprecated and only exist to allow
users to stop using them during the Nomad 0.9.x release. In the future,
there should be no expectation that the field will exist.
Currently, libcontainer-based executor, upon shutdown, kills the
container initial process. The children of the killed process remain
running, and the executor is never marked as terminated until they do.
Also, fix a case where we treat processes as successful, when
`proc.Wait()` fails. In some attempts, I was getting "waitid no child
processes" errors and such error shouldn't get process to be considered
successful.
