[keyless_]

Unfortunately, it doesn't. That was actually the reason I built this originally - there's no easy way to control read/write access to a file on S3 without using some sort of external locking system.

[IanCal]

You can add locks to objects, which restricts who can delete them and how, but requires bucket wide settings.

[maest]

BTW, this is true, but that is not locking in the "sync locking" sense.

[IanCal]

It's not the intended purpose but they can be used like this. Lock files can be written, will fail if they already exist - that gets you a distributed equivalent to flock doesn't it?

[GordonS]

Have you looked at Azure Blob Storage's lock feature? Could that be used?

[killingtime74]

Did Zookeeper or Etcd not suit your needs?

[keyless_]

They are valid solutions for this use-case; the main drawback is you need to set up and maintain a ZooKeeper cluster. Lockable is intended as a simpler and faster-to-use alternative.