Race condition in the lock acquisition

[jer]

Unless I'm mistaken, this isn't enough to prevent a race condition, right? https://github.com/websterclay/chef-dominodes/blob/master/libraries/dominodes.rb#L46

Host A fetches the databag
Host B fetches the databag
Host A writes
Host A reads
Host B writes
Host B reads

[jer]

You could probably accomplish this by having each host create an item named after itself to indicate its intent to exercise the lock. Your check could ensure that only 1 item exists. If it doesn't, you resolve the winner somehow -- perhaps by just deleting the item and starting over.