When a container died before we got into the allocation code (inside
the allocator run loop) we would not cancel the allocation since the
container death event will have been processed by the allocator before
it had any knowledge of the container.
The fix is to move the container-aliveness check inside the allocation
code. That way we still detect the death even if the event has already
flown past.
We only need to perform the check once, since any subsequent death
will result in an event that is processed by the allocator when it has
recorded the container in its state.
Fixes#1459.
otherwise we can re-insert the entry into the map after a parallel
allocateAgain() has cleared the flag. And it /that/ happens in
parallel with a free() then the data-structure can get out of sync.
It was possible to free an address between deciding to re-test it
and actually re-testing it. So introduced a flag 'block' to prevent
an address from being freed during the re-test.
Using the Ring CRDT and Weave gossip, provides an interface
for the weave script to allocate IP addresses in `weave run`,
`weave start` and `weave expose`.
See docs/ipam.md for implementation details, and site/features.md
for user-visible changes.
Matthias Radestock