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plugins/main/host-local: generate result, fix DEL, other cleanups

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This plugin needed some cleaning up: it didn't generate output, and
didn't test DEL. Add those things, plus a README.
This commit is contained in:
Casey Callendrello 2017-11-15 16:00:32 +01:00
parent 73fdc87395
commit 5e830efb20
3 changed files with 99 additions and 19 deletions
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21
plugins/main/host-device/README.md Normal file
View File

@ -0,0 +1,21 @@
# host-device
Move an already-existing device in to a container.
This simple plugin will move the requested device from the host's network namespace
to the container's. Nothing else will be done - no IPAM, no addresses.
The device can be specified with any one of three properties:
* `device`: The device name, e.g. `eth0`, `can0`
* `hwaddr`: A MAC address
* `kernelpath`: The kernel device kobj, e.g. `/sys/devices/pci0000:00/0000:00:1f.6`
For this plugin, `CNI_IFNAME` will be ignored. Upon DEL, the device will be moved back.
A sample configuration might look like:
```json
{
"cniVersion": "0.3.1",
"device": "enp0s1"
}
```

61
plugins/main/host-device/host-device.go
View File

@ -25,6 +25,7 @@ import (
"strings"
"github.com/containernetworking/cni/pkg/skel"
"github.com/containernetworking/cni/pkg/types"
"github.com/containernetworking/cni/pkg/types/current"
"github.com/containernetworking/cni/pkg/version"
"github.com/containernetworking/plugins/pkg/ns"
@ -32,6 +33,7 @@ import (
)
type NetConf struct {
types.NetConf
Device string `json:"device"` // Device-Name, something like eth0 or can0 etc.
HWAddr string `json:"hwaddr"` // MAC Address of target network interface
KernelPath string `json:"kernelpath"` // Kernelpath of the device
@ -65,8 +67,12 @@ func cmdAdd(args *skel.CmdArgs) error {
return fmt.Errorf("failed to open netns %q: %v", args.Netns, err)
}
defer containerNs.Close()
defer (&current.Result{}).Print()
return addLink(cfg.Device, cfg.HWAddr, cfg.KernelPath, containerNs)
dev, err := moveLinkIn(cfg.Device, cfg.HWAddr, cfg.KernelPath, containerNs)
if err != nil {
return fmt.Errorf("failed to move link %v", err)
}
return printLink(dev, cfg.CNIVersion, containerNs)
}
func cmdDel(args *skel.CmdArgs) error {
@ -80,35 +86,58 @@ func cmdDel(args *skel.CmdArgs) error {
}
defer containerNs.Close()
defer fmt.Println(`{}`)
return removeLink(cfg.Device, cfg.HWAddr, cfg.KernelPath, containerNs)
return moveLinkOut(cfg.Device, cfg.HWAddr, cfg.KernelPath, containerNs)
}
func addLink(device, hwAddr, kernelPath string, containerNs ns.NetNS) error {
func moveLinkIn(device, hwAddr, kernelPath string, containerNs ns.NetNS) (netlink.Link, error) {
dev, err := getLink(device, hwAddr, kernelPath)
if err != nil {
return err
return nil, err
}
if err := netlink.LinkSetNsFd(dev, int(containerNs.Fd())); err != nil {
return nil, err
}
return netlink.LinkSetNsFd(dev, int(containerNs.Fd()))
}
func removeLink(device, hwAddr, kernelPath string, containerNs ns.NetNS) error {
var dev netlink.Link
err := containerNs.Do(func(_ ns.NetNS) error {
d, err := getLink(device, hwAddr, kernelPath)
if err := containerNs.Do(func(_ ns.NetNS) error {
dev, err = netlink.LinkByName(dev.Attrs().Name)
if err != nil {
return err
}
dev = d
return nil
})
if err != nil {
return err
}); err != nil {
return nil, err
}
return dev, nil
}
func moveLinkOut(device, hwAddr, kernelPath string, containerNs ns.NetNS) error {
defaultNs, err := ns.GetCurrentNS()
if err != nil {
return err
}
return netlink.LinkSetNsFd(dev, int(defaultNs.Fd()))
return containerNs.Do(func(_ ns.NetNS) error {
dev, err := getLink(device, hwAddr, kernelPath)
if err != nil {
return err
}
return netlink.LinkSetNsFd(dev, int(defaultNs.Fd()))
})
}
func printLink(dev netlink.Link, cniVersion string, containerNs ns.NetNS) error {
result := current.Result{
CNIVersion: current.ImplementedSpecVersion,
Interfaces: []*current.Interface{
{
Name: dev.Attrs().Name,
Mac: dev.Attrs().HardwareAddr.String(),
Sandbox: containerNs.Path(),
},
},
}
return types.PrintResult(&result, cniVersion)
}
func getLink(devname, hwaddr, kernelpath string) (netlink.Link, error) {

36
plugins/main/host-device/host-device_test.go
View File

@ -19,6 +19,8 @@ import (
"math/rand"
"github.com/containernetworking/cni/pkg/skel"
"github.com/containernetworking/cni/pkg/types"
"github.com/containernetworking/cni/pkg/types/current"
"github.com/containernetworking/plugins/pkg/ns"
"github.com/containernetworking/plugins/pkg/testutils"
. "github.com/onsi/ginkgo"
@ -44,6 +46,8 @@ var _ = Describe("base functionality", func() {
It("Works with a valid config", func() {
var origLink netlink.Link
// prepare ifname in original namespace
err := originalNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()
@ -53,9 +57,9 @@ var _ = Describe("base functionality", func() {
},
})
Expect(err).NotTo(HaveOccurred())
link, err := netlink.LinkByName(ifname)
origLink, err = netlink.LinkByName(ifname)
Expect(err).NotTo(HaveOccurred())
err = netlink.LinkSetUp(link)
err = netlink.LinkSetUp(origLink)
Expect(err).NotTo(HaveOccurred())
return nil
})
@ -77,13 +81,26 @@ var _ = Describe("base functionality", func() {
IfName: ifname,
StdinData: []byte(conf),
}
var resI types.Result
err = originalNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()
_, _, err := testutils.CmdAddWithResult(targetNS.Path(), ifname, []byte(conf), func() error { return cmdAdd(args) })
var err error
resI, _, err = testutils.CmdAddWithResult(targetNS.Path(), ifname, []byte(conf), func() error { return cmdAdd(args) })
return err
})
Expect(err).NotTo(HaveOccurred())
// check that the result was sane
res, err := current.NewResultFromResult(resI)
Expect(err).NotTo(HaveOccurred())
Expect(res.Interfaces).To(Equal([]*current.Interface{
{
Name: ifname,
Mac: origLink.Attrs().HardwareAddr.String(),
Sandbox: targetNS.Path(),
},
}))
// assert that dummy0 is now in the target namespace
err = targetNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()
@ -102,6 +119,19 @@ var _ = Describe("base functionality", func() {
return nil
})
Expect(err).NotTo(HaveOccurred())
// Check that deleting the device moves it back
err = originalNS.Do(func(ns.NetNS) error {
defer GinkgoRecover()
err = testutils.CmdDelWithResult(targetNS.Path(), ifname, func() error { return cmdDel(args) })
Expect(err).NotTo(HaveOccurred())
_, err := netlink.LinkByName(ifname)
Expect(err).NotTo(HaveOccurred())
return nil
})
Expect(err).NotTo(HaveOccurred())
})
It("fails an invalid config", func() {