In real-world address allocations, disjoint address ranges are common.
Therefore, the host-local allocator should support them.
This change still allows for multiple IPs in a single configuration, but
also allows for a "set of subnets."
Fixes: #45
This change allows the host-local allocator to allocate multiple IPs.
This is intended to enable dual-stack, but is not limited to only two
subnets or separate address families.
Updates the spec and plugins to return an array of interfaces and IP details
to the runtime including:
- interface names and MAC addresses configured by the plugin
- whether the interfaces are sandboxed (container/VM) or host (bridge, veth, etc)
- multiple IP addresses configured by IPAM and which interface they
have been assigned to
Returning interface details is useful for runtimes, as well as allowing
more flexible chaining of CNI plugins themselves. For example, some
meta plugins may need to know the host-side interface to be able to
apply firewall or traffic shaping rules to the container.
