Implement a new bitmap allocator using an allocation strategy that accepts
and offset and subdivides the range based on this offset, prioritizing the
upper range for dynamic allocation.
The service allocator is used to allocate ip addresses for the
Service IP allocator and NodePorts for the Service NodePort
allocator. It uses a bitmap backed by etcd to store the allocation
and tries to allocate the resources directly from the local memory
instead from etcd, that can cause issues in environment with
high concurrency.
It may happen, in deployments with multiple apiservers, that the
resource allocation information is out of sync, this is more
sensible with NodePorts, per example:
1. apiserver A create a service with NodePort X
2. apiserver B deletes the service
3. apiserver A creates the service again
If the allocation data of apiserver A wasn't refreshed with the
deletion of apiserver B, apiserver A fails the allocation because
the data is out of sync. The Repair loops solve the problem later,
but there are some use cases that require to improve the concurrency
in the allocation logic.
We can try to not do the Allocation and Release operations locally,
and try instead to check if the local data is up to date with etcd,
and operate over the most recent version of the data.
The DestroyFunc functions returned by generic.NewRawStorage is never
called when we do a StartTestServer() in the test suite. For a quick
hack for now, added TrackStorageCleanup/RegisterStorageCleanup and
CleanupStorage. Note that unless TrackStorageCleanup is called (which
is called only from the test suite) the other two methods are
no-ops essentially. So no change in behavior at runtime. This vastly
brings down the number of goroutines that are left behind when this
test is executed and should reduce if not eliminate the flakiness
of TestCRD
