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Merge pull request #273 from zreigz/reconfigure-bridge-ip

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Reconfigure bridge IP address
This commit is contained in:
Tom Denham 2016-08-12 15:04:22 -07:00 committed by GitHub
commit 5a67f5d6fb
5 changed files with 224 additions and 11 deletions
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2
Documentation/bridge.md
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@ -18,6 +18,7 @@ If the bridge is missing, the plugin will create one on first use and, if gatewa
"type": "bridge",
"bridge": "mynet0",
"isDefaultGateway": true,
"forceAddress": false,
"ipMasq": true,
"hairpinMode": true,
"ipam": {
@ -34,6 +35,7 @@ If the bridge is missing, the plugin will create one on first use and, if gatewa
* `bridge` (string, optional): name of the bridge to use/create. Defaults to "cni0".
* `isGateway` (boolean, optional): assign an IP address to the bridge. Defaults to false.
* `isDefaultGateway` (boolean, optional): Sets isGateway to true and makes the assigned IP the default route. Defaults to false.
* `forceAddress` (boolean, optional): Indicates if a new IP address should be set if the previous value has been changed. Defaults to false.
* `ipMasq` (boolean, optional): set up IP Masquerade on the host for traffic originating from this network and destined outside of it. Defaults to false.
* `mtu` (integer, optional): explicitly set MTU to the specified value. Defaults to the value chosen by the kernel.
* `hairpinMode` (boolean, optional): set hairpin mode for interfaces on the bridge. Defaults to false.

25
libcni/conf.go
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@ -83,3 +83,28 @@ func LoadConf(dir, name string) (*NetworkConfig, error) {
}
return nil, fmt.Errorf(`no net configuration with name "%s" in %s`, name, dir)
}
func InjectConf(original *NetworkConfig, key string, newValue interface{}) (*NetworkConfig, error) {
config := make(map[string]interface{})
err := json.Unmarshal(original.Bytes, &config)
if err != nil {
return nil, fmt.Errorf("unmarshal existing network bytes: %s", err)
}
if key == "" {
return nil, fmt.Errorf("key value can not be empty")
}
if newValue == nil {
return nil, fmt.Errorf("newValue must be specified")
}
config[key] = newValue
newBytes, err := json.Marshal(config)
if err != nil {
return nil, err
}
return ConfFromBytes(newBytes)
}

89
libcni/conf_test.go
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@ -29,6 +29,7 @@ var _ = Describe("Loading configuration from disk", func() {
var (
configDir string
pluginConfig []byte
testNetConfig *libcni.NetworkConfig
)
BeforeEach(func() {
@ -38,6 +39,9 @@ var _ = Describe("Loading configuration from disk", func() {
pluginConfig = []byte(`{ "name": "some-plugin", "some-key": "some-value" }`)
Expect(ioutil.WriteFile(filepath.Join(configDir, "50-whatever.conf"), pluginConfig, 0600)).To(Succeed())
testNetConfig = &libcni.NetworkConfig{Network: &types.NetConf{Name: "some-plugin"},
Bytes: []byte(`{ "name": "some-plugin" }`)}
})
AfterEach(func() {
@ -107,4 +111,89 @@ var _ = Describe("Loading configuration from disk", func() {
})
})
})
Describe("InjectConf", func() {
Context("when function parameters are incorrect", func() {
It("returns unmarshal error", func() {
conf := &libcni.NetworkConfig{Network: &types.NetConf{Name: "some-plugin"},
Bytes: []byte(`{ cc cc cc}`)}
_, err := libcni.InjectConf(conf, "", nil)
Expect(err).To(MatchError(HavePrefix(`unmarshal existing network bytes`)))
})
It("returns key error", func() {
_, err := libcni.InjectConf(testNetConfig, "", nil)
Expect(err).To(MatchError(HavePrefix(`key value can not be empty`)))
})
It("returns newValue error", func() {
_, err := libcni.InjectConf(testNetConfig, "test", nil)
Expect(err).To(MatchError(HavePrefix(`newValue must be specified`)))
})
})
Context("when new string value added", func() {
It("adds the new key & value to the config", func() {
newPluginConfig := []byte(`{"name":"some-plugin","test":"test"}`)
resultConfig, err := libcni.InjectConf(testNetConfig, "test", "test")
Expect(err).NotTo(HaveOccurred())
Expect(resultConfig).To(Equal(&libcni.NetworkConfig{
Network: &types.NetConf{Name: "some-plugin"},
Bytes: newPluginConfig,
}))
})
It("adds the new value for exiting key", func() {
newPluginConfig := []byte(`{"name":"some-plugin","test":"changedValue"}`)
resultConfig, err := libcni.InjectConf(testNetConfig, "test", "test")
Expect(err).NotTo(HaveOccurred())
resultConfig, err = libcni.InjectConf(resultConfig, "test", "changedValue")
Expect(err).NotTo(HaveOccurred())
Expect(resultConfig).To(Equal(&libcni.NetworkConfig{
Network: &types.NetConf{Name: "some-plugin"},
Bytes: newPluginConfig,
}))
})
It("adds existing key & value", func() {
newPluginConfig := []byte(`{"name":"some-plugin","test":"test"}`)
resultConfig, err := libcni.InjectConf(testNetConfig, "test", "test")
Expect(err).NotTo(HaveOccurred())
resultConfig, err = libcni.InjectConf(resultConfig, "test", "test")
Expect(err).NotTo(HaveOccurred())
Expect(resultConfig).To(Equal(&libcni.NetworkConfig{
Network: &types.NetConf{Name: "some-plugin"},
Bytes: newPluginConfig,
}))
})
It("adds sub-fields of NetworkConfig.Network to the config", func() {
expectedPluginConfig := []byte(`{"dns":{"domain":"local","nameservers":["server1","server2"]},"name":"some-plugin","type":"bridge"}`)
servers := []string{"server1", "server2"}
newDNS := &types.DNS{Nameservers: servers, Domain: "local"}
// inject DNS
resultConfig, err := libcni.InjectConf(testNetConfig, "dns", newDNS)
Expect(err).NotTo(HaveOccurred())
// inject type
resultConfig, err = libcni.InjectConf(resultConfig, "type", "bridge")
Expect(err).NotTo(HaveOccurred())
Expect(resultConfig).To(Equal(&libcni.NetworkConfig{
Network: &types.NetConf{Name: "some-plugin", Type: "bridge", DNS: types.DNS{Nameservers: servers, Domain: "local"}},
Bytes: expectedPluginConfig,
}))
})
})
})
})

31
plugins/main/bridge/bridge.go
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 {
@ -266,7 +293,7 @@ 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
}

70
plugins/main/bridge/bridge_test.go
View File

@ -251,4 +251,74 @@ 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())
})
})