TODO(jdef) we use a Locker to guard against concurrent task state changes, but it would bereally, really nice to avoid doing this.

makePodKey constructs etcd paths to pod items enforcing namespace rules.

reconstruct a task from metadata stashed in a pod entry.

maps a Container.HostPort to the same exact offered host port, ignores .HostPort = 0.

same as HostPortMappingFixed, except that .HostPort of 0 are mapped to any port offered.

TODO(jdef) move this somewhere else.

A struct that describes a pod task.

state store for pod tasks.