* alloc_runner
* Random tests
* parallel task_runner and no exec compatible check
* Parallel client
* Fail fast and use random ports
* Fix docker port mapping
* Make concurrent pull less timing dependant
* up parallel
* Fixes
* don't build chroots in parallel on travis
* Reduce parallelism on travis with lxc/rkt
* make java test app not run forever
* drop parallelism a little
* use docker ports that are out of the os's ephemeral port range
* Limit even more on travis
* rkt deadline
When replacing an alloc the new alloc is blocked until the old alloc is
destroyed. This could cause a deadlock:
1. Destroying the old alloc includes a final sync of its status
2. Syncing status causes a GC
3. A GC looks for terminal allocs to cleanup
4. The GC waits for an alloc to stop completely before GC'ing
If the GC chooses the currently-being-destroyed-alloc to GC, the GC
deadlocks. If `client.max_parallel` deadlocks happen the GC is wedged
until the Nomad process is restarted.
Performing the final sync asynchronously is an ugly hack but prevents
the deadlock by allowing the final sync to occur after the alloc runner
has shutdown and been destroyed.
Since the AllocRunner.alloc struct can be mutated, most of AllocRunner
needs to acquire a lock to get the alloc's ID. Log lines always need to
include the alloc ID, so we often skipped acquiring a lock just to grab
the ID and accepted the race.
Let's make the race detector a little happier by storing the ID in a
single assignment field.
Task dir metadata is created in AllocRunner.Run which may not run before
an alloc is sync'd and Nomad exits. There's no reason not to just create
task dir metadata on restore if it doesn't exist.
Fixes#2835
Yet another bug caused by overwriting container and then trying to
reference container.ID in the err handling block. Did a quick audit of
docker.go and it seems to be the last offender. See #2804 for previous
bug.
