libnetwork/cnmallocator/drivers_ipam.go:43:31: printf: non-constant format string in call to (*github.com/docker/docker/vendor/github.com/sirupsen/logrus.Entry).Infof (govet)
log.G(context.TODO()).Infof("Swarm initialized global default address pool to: " + str.String())
^
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The previous allocator was subnetting address pools eagerly
when the daemon started, and would then just iterate over that
list whenever RequestPool was called. This was leading to high
memory usage whenever IPv6 pools were configured with a target
subnet size too different from the pools prefix size.
For instance: pool = fd00::/8, target size = /64 -- 2 ^ (64-8)
subnets would be generated upfront. This would take approx.
9 * 10^18 bits -- way too much for any human computer in 2024.
Another noteworthy issue, the previous implementation was allocating
a subnet, and then in another layer was checking whether the
allocation was conflicting with some 'reserved networks'. If so,
the allocation would be retried, etc... To make it worse, 'reserved
networks' would be recomputed on every iteration. This is totally
ineffective as there could be 'reserved networks' that fully overlap
a given address pool (or many!).
To fix this issue, a new field `Exclude` is added to `RequestPool`.
It's up to each driver to take it into account. Since we don't know
whether this retry loop is useful for some remote IPAM driver, it's
reimplemented bug-for-bug directly in the remote driver.
The new allocator uses a linear-search algorithm. It takes advantage
of all lists (predefined pools, allocated subnets and reserved
networks) being sorted and logically combines 'allocated' and
'reserved' through a 'double cursor' to iterate on both lists at the
same time while preserving the total order. At the same time, it
iterates over 'predefined' pools and looks for the first empty space
that would be a good fit.
Currently, the size of the allocated subnet is still dictated by
each 'predefined' pools. We should consider hardcoding that size
instead, and let users specify what subnet size they want. This
wasn't possible before as the subnets were generated upfront. This
new allocator should be able to deal with this easily.
The method used for static allocation has been updated to make sure
the ascending order of 'allocated' is preserved. It's bug-for-bug
compatible with the previous implementation.
One consequence of this new algorithm is that we don't keep track
of where the last allocation happened, we just allocate the first
free subnet we find.
Before:
- Allocate: 10.0.1.0/24, 10.0.2.0/24 ; Deallocate: 10.0.1.0/24 ;
Allocate 10.0.3.0/24.
Now, the 3rd allocation would yield 10.0.1.0/24 once again.
As it doesn't change the semantics of the allocator, there's no
reason to worry about that.
Finally, about 'reserved networks'. The heuristics we use are
now properly documented. It was discovered that we don't check
routes for IPv6 allocations -- this can't be changed because
there's no such thing as on-link routes for IPv6.
(Kudos to Rob Murray for coming up with the linear-search idea.)
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
Prior to this change, cnmallocator would call
`ConfigGlobalScopeDefaultNetworks` right before initializing its
IPAM drivers. This function was mutating some global state used
during drivers init.
This change just remove the global state, and adds an arg to
ipams.Register and defaultipam.Register to pass the global pools
by arguments instead.
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
Packages in libnet/ipams are drivers, except builtin -- it's used
to register drivers. Move files one level up and delete this pkg.
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
Prior to this change, daemon's `default-address-pools` param would
be passed to `SetDefaultIPAddressPool()` to set a global var named
`defaultAddressPool`. This var would then be retrieved during the
`default` IPAM driver registration. Both steps were executed in
close succession during libnet's controller initialization.
This change removes the global var and just pass the user-defined
`default-address-pools` to the `default` driver's `Register` fn.
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
The `RequestPool` method has many args and named returns. This
makes the code hard to follow at times. This commit adds one struct,
`PoolRequest`, to replace these args, and one struct, `AllocatedPool`,
to replace these named returns.
Both structs' fields are properly documented to better define their
semantics, and their relationship with address allocation.
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
Apply command gotest.tools/v3/assert/cmd/gty-migrate-from-testify to the
cnmallocator package to be consistent with the assertion library used
elsewhere in moby.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Moby imports Swarmkit; Swarmkit no longer imports Moby. In order to
accomplish this feat, Swarmkit has introduced a new plugin.Getter
interface so it could stop importing our pkg/plugingetter package. This
new interface is not entirely compatible with our
plugingetter.PluginGetter interface, necessitating a thin adapter.
Swarmkit had to jettison the CNM network allocator to stop having to
import libnetwork as the cnmallocator package is deeply tied to
libnetwork. Move the CNM network allocator into libnetwork, where it
belongs. The package had a short an uninteresting Git history in the
Swarmkit repository so no effort was made to retain history.
Signed-off-by: Cory Snider <csnider@mirantis.com>
