func setupIpMasq(localNet ip.IP4Net, overlayNet ip.IP4Net) error {
ipt, err := ip.NewIPTables()
if err != nil {
return err
}
err = ipt.ClearChain("nat", "FLANNEL")
if err != nil {
return fmt.Errorf("Failed to create/clear FLANNEL chain in NAT table: %v", err)
}
rules := [][]string{
{"FLANNEL", "-s", localNet.String(), "-o", "lo", "-j", "ACCEPT"},
{"FLANNEL", "-s", localNet.String(), "!", "-d", overlayNet.String(), "-j", "MASQUERADE"},
{"POSTROUTING", "-s", localNet.String(), "-j", "FLANNEL"},
}
for _, args := range rules {
log.Info("Adding iptables rule: ", strings.Join(args, " "))
if err := ipt.AppendUnique("nat", args...); err != nil {
return fmt.Errorf("Failed to insert IP masquerade rule: %v", err)
}
}
return nil
}
