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macvlan: set mac address from CNI_ARGS
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This change sets the mac address if specified during the creation of the
macvlan interface. This is superior to setting it via the tuning plugin
because this ensures the mac address is set before an IP is set,
allowing a container to get a reserved IP address from DHCP.

Related containernetworking#450

Signed-off-by: Clint Armstrong <[email protected]>
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@clinta @amorenoz
clinta authored and amorenoz committed Sep 7, 2020
1 parent 219eb9e commit e986a1c
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Showing 2 changed files with 220 additions and 11 deletions.
59 changes: 48 additions & 11 deletions plugins/main/macvlan/macvlan.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,17 @@ type NetConf struct {
Master string `json:"master"`
Mode string `json:"mode"`
MTU int `json:"mtu"`
Mac string `json:"mac,omitempty"`

RuntimeConfig struct {
Mac string `json:"mac,omitempty"`
} `json:"runtimeConfig,omitempty"`
}

// MacEnvArgs represents CNI_ARG
type MacEnvArgs struct {
types.CommonArgs
MAC types.UnmarshallableString `json:"mac,omitempty"`
}

func init() {
Expand Down Expand Up @@ -73,7 +84,7 @@ func getDefaultRouteInterfaceName() (string, error) {
return "", fmt.Errorf("no default route interface found")
}

func loadConf(bytes []byte) (*NetConf, string, error) {
func loadConf(bytes []byte, envArgs string) (*NetConf, string, error) {
n := &NetConf{}
if err := json.Unmarshal(bytes, n); err != nil {
return nil, "", fmt.Errorf("failed to load netconf: %v", err)
Expand All @@ -95,6 +106,22 @@ func loadConf(bytes []byte) (*NetConf, string, error) {
return nil, "", fmt.Errorf("invalid MTU %d, must be [0, master MTU(%d)]", n.MTU, masterMTU)
}

if envArgs != "" {
e := MacEnvArgs{}
err := types.LoadArgs(envArgs, &e)
if err != nil {
return nil, "", err
}

if e.MAC != "" {
n.Mac = string(e.MAC)
}
}

if n.RuntimeConfig.Mac != "" {
n.Mac = n.RuntimeConfig.Mac
}

return n, n.CNIVersion, nil
}

Expand Down Expand Up @@ -156,14 +183,24 @@ func createMacvlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Inter
return nil, err
}

linkAttrs := netlink.LinkAttrs{
MTU: conf.MTU,
Name: tmpName,
ParentIndex: m.Attrs().Index,
Namespace: netlink.NsFd(int(netns.Fd())),
}

if conf.Mac != "" {
addr, err := net.ParseMAC(conf.Mac)
if err != nil {
return nil, fmt.Errorf("invalid args %v for MAC addr: %v", conf.Mac, err)
}
linkAttrs.HardwareAddr = addr
}

mv := &netlink.Macvlan{
LinkAttrs: netlink.LinkAttrs{
MTU: conf.MTU,
Name: tmpName,
ParentIndex: m.Attrs().Index,
Namespace: netlink.NsFd(int(netns.Fd())),
},
Mode: mode,
LinkAttrs: linkAttrs,
Mode: mode,
}

if err := netlink.LinkAdd(mv); err != nil {
Expand Down Expand Up @@ -204,7 +241,7 @@ func createMacvlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Inter
}

func cmdAdd(args *skel.CmdArgs) error {
n, cniVersion, err := loadConf(args.StdinData)
n, cniVersion, err := loadConf(args.StdinData, args.Args)
if err != nil {
return err
}
Expand Down Expand Up @@ -311,7 +348,7 @@ func cmdAdd(args *skel.CmdArgs) error {
}

func cmdDel(args *skel.CmdArgs) error {
n, _, err := loadConf(args.StdinData)
n, _, err := loadConf(args.StdinData, args.Args)
if err != nil {
return err
}
Expand Down Expand Up @@ -349,7 +386,7 @@ func main() {

func cmdCheck(args *skel.CmdArgs) error {

n, _, err := loadConf(args.StdinData)
n, _, err := loadConf(args.StdinData, args.Args)
if err != nil {
return err
}
Expand Down
172 changes: 172 additions & 0 deletions plugins/main/macvlan/macvlan_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -594,4 +594,176 @@ var _ = Describe("macvlan Operations", func() {
Expect(err).NotTo(HaveOccurred())
})

It("configures and deconfigures l2 macvlan link with mac address (from CNI_ARGS) with CNI v4 ADD/DEL", func() {
const IFNAME = "macvl0"

conf := fmt.Sprintf(`{
"cniVersion": "0.3.1",
"name": "mynet",
"type": "macvlan",
"master": "%s",
"ipam": {}
}`, MASTER_NAME)

targetNs, err := testutils.NewNS()
Expect(err).NotTo(HaveOccurred())
defer targetNs.Close()

args := &skel.CmdArgs{
ContainerID: "dummy",
Netns: targetNs.Path(),
IfName: IFNAME,
StdinData: []byte(conf),
Args: "IgnoreUnknown=true;MAC=c2:11:22:33:44:55",
}

var result *current.Result
err = originalNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()

r, _, err := testutils.CmdAddWithArgs(args, func() error {
return cmdAdd(args)
})
Expect(err).NotTo(HaveOccurred())

result, err = current.GetResult(r)
Expect(err).NotTo(HaveOccurred())

Expect(len(result.Interfaces)).To(Equal(1))
Expect(result.Interfaces[0].Name).To(Equal(IFNAME))
Expect(len(result.IPs)).To(Equal(0))

return nil
})
Expect(err).NotTo(HaveOccurred())

// Make sure macvlan link exists in the target namespace
err = targetNs.Do(func(ns.NetNS) error {
defer GinkgoRecover()

link, err := netlink.LinkByName(IFNAME)
Expect(err).NotTo(HaveOccurred())
Expect(link.Attrs().Name).To(Equal(IFNAME))

hwaddr, err := net.ParseMAC("c2:11:22:33:44:55")
Expect(err).NotTo(HaveOccurred())
Expect(link.Attrs().HardwareAddr).To(Equal(hwaddr))

addrs, err := netlink.AddrList(link, syscall.AF_INET)
Expect(err).NotTo(HaveOccurred())
Expect(len(addrs)).To(Equal(0))
return nil
})
Expect(err).NotTo(HaveOccurred())

err = originalNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()

err := testutils.CmdDelWithArgs(args, func() error {
return cmdDel(args)
})
Expect(err).NotTo(HaveOccurred())
return nil
})
Expect(err).NotTo(HaveOccurred())

// Make sure macvlan link has been deleted
err = targetNs.Do(func(ns.NetNS) error {
defer GinkgoRecover()

link, err := netlink.LinkByName(IFNAME)
Expect(err).To(HaveOccurred())
Expect(link).To(BeNil())
return nil
})
Expect(err).NotTo(HaveOccurred())
})

It("configures and deconfigures l2 macvlan link with mac address (from RuntimeConfig) with ADD/DEL", func() {
const IFNAME = "macvl0"

conf := fmt.Sprintf(`{
"cniVersion": "0.3.1",
"capabilities": {"mac": true},
"RuntimeConfig": {
"mac": "c2:11:22:33:44:55"
},
"name": "mynet",
"type": "macvlan",
"master": "%s",
"ipam": {}
}`, MASTER_NAME)

targetNs, err := testutils.NewNS()
Expect(err).NotTo(HaveOccurred())
defer targetNs.Close()

args := &skel.CmdArgs{
ContainerID: "dummy",
Netns: targetNs.Path(),
IfName: IFNAME,
StdinData: []byte(conf),
}

var result *current.Result
err = originalNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()

r, _, err := testutils.CmdAddWithArgs(args, func() error {
return cmdAdd(args)
})
Expect(err).NotTo(HaveOccurred())

result, err = current.GetResult(r)
Expect(err).NotTo(HaveOccurred())

Expect(len(result.Interfaces)).To(Equal(1))
Expect(result.Interfaces[0].Name).To(Equal(IFNAME))
Expect(len(result.IPs)).To(Equal(0))

return nil
})
Expect(err).NotTo(HaveOccurred())

// Make sure macvlan link exists in the target namespace
err = targetNs.Do(func(ns.NetNS) error {
defer GinkgoRecover()

link, err := netlink.LinkByName(IFNAME)
Expect(err).NotTo(HaveOccurred())
Expect(link.Attrs().Name).To(Equal(IFNAME))

hwaddr, err := net.ParseMAC("c2:11:22:33:44:55")
Expect(err).NotTo(HaveOccurred())
Expect(link.Attrs().HardwareAddr).To(Equal(hwaddr))

addrs, err := netlink.AddrList(link, syscall.AF_INET)
Expect(err).NotTo(HaveOccurred())
Expect(len(addrs)).To(Equal(0))
return nil
})
Expect(err).NotTo(HaveOccurred())

err = originalNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()

err := testutils.CmdDelWithArgs(args, func() error {
return cmdDel(args)
})
Expect(err).NotTo(HaveOccurred())
return nil
})
Expect(err).NotTo(HaveOccurred())

// Make sure macvlan link has been deleted
err = targetNs.Do(func(ns.NetNS) error {
defer GinkgoRecover()

link, err := netlink.LinkByName(IFNAME)
Expect(err).To(HaveOccurred())
Expect(link).To(BeNil())
return nil
})
Expect(err).NotTo(HaveOccurred())
})
})

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