func configureIface(ifname string, ipn ip.IP4Net, mtu int) error {
iface, err := netlink.LinkByName(ifname)
if err != nil {
return fmt.Errorf("failed to lookup interface %v", ifname)
}
err = netlink.AddrAdd(iface, &netlink.Addr{ipn.ToIPNet(), ""})
if err != nil {
return fmt.Errorf("failed to add IP address %v to %v: %v", ipn.String(), ifname, err)
}
err = netlink.LinkSetMTU(iface, mtu)
if err != nil {
return fmt.Errorf("failed to set MTU for %v: %v", ifname, err)
}
err = netlink.LinkSetUp(iface)
if err != nil {
return fmt.Errorf("failed to set interface %v to UP state: %v", ifname, err)
}
// explicitly add a route since there might be a route for a subnet already
// installed by Docker and then it won't get auto added
err = netlink.RouteAdd(&netlink.Route{
LinkIndex: iface.Attrs().Index,
Scope: netlink.SCOPE_UNIVERSE,
Dst: ipn.Network().ToIPNet(),
})
if err != nil && err != syscall.EEXIST {
return fmt.Errorf("Failed to add route (%v -> %v): %v", ipn.Network().String(), ifname, err)
}
return nil
}
// sets IP4 addr on link removing any existing ones first
func setAddr4(link *netlink.Vxlan, ipn *net.IPNet) error {
addrs, err := netlink.AddrList(link, syscall.AF_INET)
if err != nil {
return err
}
for _, addr := range addrs {
if err = netlink.AddrDel(link, &addr); err != nil {
return fmt.Errorf("failed to delete IPv4 addr %s from %s", addr.String(), link.Attrs().Name)
}
}
addr := netlink.Addr{ipn, ""}
if err = netlink.AddrAdd(link, &addr); err != nil {
return fmt.Errorf("failed to add IP address %s to %s: %s", ipn.String(), link.Attrs().Name, err)
}
return nil
}