client/freeips.go

package client

import (
	"github.com/aws/cni-k8s-tool/nl"
)

// FindFreeIPsAtIndex locates free IP addresses by comparing the assigned list
// from the EC2 metadata service and the currently used addresses
// within netlink. This is inherently somewhat racey - for example
// newly provisioned addresses may not show up immediately in metadata
// and are subject to a few seconds of delay.
func FindFreeIPsAtIndex(index int, updateRegistry bool) ([]*AllocationResult, error) {
	freeIps := []*AllocationResult{}
	//registry := &Registry{}

	interfaces, err := DefaultClient.GetInterfaces()
	if err != nil {
		return nil, err
	}
	assigned, err := nl.GetIPs()
	if err != nil {
		return nil, err
	}

	for _, intf := range interfaces {
		if intf.Number < index {
			continue
		}
		for _, intfIP := range intf.IPv4s {
			found := false
			for _, assignedIP := range assigned {
				if assignedIP.IPNet.IP.Equal(intfIP) {
					found = true
					break
				}
			}
			if !found {
				intfIPCopy := intfIP
				// No match, record as free
				freeIps = append(freeIps, &AllocationResult{
					&intfIPCopy,
					intf,
				})
			}
			/*if updateRegistry {
				if exists, err := registry.HasIP(intfIP); err == nil && !exists && !found {
					// track IP as free if it hasn't been registered before
					registry.TrackIP(intfIP)
				} else if found {
					// mark IP as in use
					registry.ForgetIP(intfIP)
				}
			}*/
		}
	}

	return freeIps, nil
}