plugins: reconfigure bridge IP address

Add possibility to reconfigure bridge IP address when there is a new value.
New boolean flag added to net configuration to force IP change if it is need.
Otherwise code behaves as previously and throws error
This commit is contained in:
Lukasz Zajaczkowski 2016-07-29 13:02:32 +02:00
parent c1ff202179
commit d09b18dac4
2 changed files with 106 additions and 9 deletions

View File

@ -38,6 +38,7 @@ type NetConf struct {
BrName string `json:"bridge"`
IsGW bool `json:"isGateway"`
IsDefaultGW bool `json:"isDefaultGateway"`
ForceAddress bool `json:"forceAddress"`
IPMasq bool `json:"ipMasq"`
MTU int `json:"mtu"`
HairpinMode bool `json:"hairpinMode"`
@ -60,7 +61,7 @@ func loadNetConf(bytes []byte) (*NetConf, error) {
return n, nil
}
func ensureBridgeAddr(br *netlink.Bridge, ipn *net.IPNet) error {
func ensureBridgeAddr(br *netlink.Bridge, ipn *net.IPNet, forceAddress bool) error {
addrs, err := netlink.AddrList(br, syscall.AF_INET)
if err != nil && err != syscall.ENOENT {
return fmt.Errorf("could not get list of IP addresses: %v", err)
@ -74,9 +75,17 @@ func ensureBridgeAddr(br *netlink.Bridge, ipn *net.IPNet) error {
if a.IPNet.String() == ipnStr {
return nil
}
// If forceAddress is set to true then reconfigure IP address otherwise throw error
if forceAddress {
if err = deleteBridgeAddr(br, a.IPNet); err != nil {
return err
}
} else {
return fmt.Errorf("%q already has an IP address different from %v", br.Name, ipn.String())
}
}
}
addr := &netlink.Addr{IPNet: ipn, Label: ""}
if err := netlink.AddrAdd(br, addr); err != nil {
@ -85,6 +94,24 @@ func ensureBridgeAddr(br *netlink.Bridge, ipn *net.IPNet) error {
return nil
}
func deleteBridgeAddr(br *netlink.Bridge, ipn *net.IPNet) error {
addr := &netlink.Addr{IPNet: ipn, Label: ""}
if err := netlink.LinkSetDown(br); err != nil {
return fmt.Errorf("could not set down bridge %q: %v", br.Name, err)
}
if err := netlink.AddrDel(br, addr); err != nil {
return fmt.Errorf("could not remove IP address from %q: %v", br.Name, err)
}
if err := netlink.LinkSetUp(br); err != nil {
return fmt.Errorf("could not set up bridge %q: %v", br.Name, err)
}
return nil
}
func bridgeByName(name string) (*netlink.Bridge, error) {
l, err := netlink.LinkByName(name)
if err != nil {
@ -258,7 +285,7 @@ func cmdAdd(args *skel.CmdArgs) error {
Mask: result.IP4.IP.Mask,
}
if err = ensureBridgeAddr(br, gwn); err != nil {
if err = ensureBridgeAddr(br, gwn, n.ForceAddress); err != nil {
return err
}

View File

@ -236,4 +236,74 @@ var _ = Describe("bridge Operations", func() {
})
Expect(err).NotTo(HaveOccurred())
})
It("ensure bridge address", func() {
const IFNAME = "bridge0"
const EXPECTED_IP = "10.0.0.0/8"
const CHANGED_EXPECTED_IP = "10.1.2.3/16"
conf := &NetConf{
NetConf: types.NetConf{
Name: "testConfig",
Type: "bridge",
},
BrName: IFNAME,
IsGW: true,
IPMasq: false,
MTU: 5000,
}
gwnFirst := &net.IPNet{
IP: net.IPv4(10, 0, 0, 0),
Mask: net.CIDRMask(8, 32),
}
gwnSecond := &net.IPNet{
IP: net.IPv4(10, 1, 2, 3),
Mask: net.CIDRMask(16, 32),
}
err := originalNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()
bridge, err := setupBridge(conf)
Expect(err).NotTo(HaveOccurred())
// Check if ForceAddress has default value
Expect(conf.ForceAddress).To(Equal(false))
err = ensureBridgeAddr(bridge, gwnFirst, conf.ForceAddress)
Expect(err).NotTo(HaveOccurred())
//Check if IP address is set correctly
addrs, err := netlink.AddrList(bridge, syscall.AF_INET)
Expect(len(addrs)).To(Equal(1))
addr := addrs[0].IPNet.String()
Expect(addr).To(Equal(EXPECTED_IP))
//The bridge IP address has been changed. Error expected when ForceAddress is set to false.
err = ensureBridgeAddr(bridge, gwnSecond, false)
Expect(err).To(HaveOccurred())
//The IP address should stay the same.
addrs, err = netlink.AddrList(bridge, syscall.AF_INET)
Expect(len(addrs)).To(Equal(1))
addr = addrs[0].IPNet.String()
Expect(addr).To(Equal(EXPECTED_IP))
//Reconfigure IP when ForceAddress is set to true and IP address has been changed.
err = ensureBridgeAddr(bridge, gwnSecond, true)
Expect(err).NotTo(HaveOccurred())
//Retrieve the IP address after reconfiguration
addrs, err = netlink.AddrList(bridge, syscall.AF_INET)
Expect(len(addrs)).To(Equal(1))
addr = addrs[0].IPNet.String()
Expect(addr).To(Equal(CHANGED_EXPECTED_IP))
return nil
})
Expect(err).NotTo(HaveOccurred())
})
})