Golang NetNS.Do方法代码示例

func setupVeth(netns ns.NetNS, br *netlink.Bridge, ifName string, mtu int, hairpinMode bool) error {
	var hostVethName string

	err := netns.Do(func(hostNS ns.NetNS) error {
		// create the veth pair in the container and move host end into host netns
		hostVeth, _, err := ip.SetupVeth(ifName, mtu, hostNS)
		if err != nil {
			return err
		}

		hostVethName = hostVeth.Attrs().Name
		return nil
	})
	if err != nil {
		return err
	}

	// need to lookup hostVeth again as its index has changed during ns move
	hostVeth, err := netlink.LinkByName(hostVethName)
	if err != nil {
		return fmt.Errorf("failed to lookup %q: %v", hostVethName, err)
	}

	// connect host veth end to the bridge
	if err = netlink.LinkSetMaster(hostVeth, br); err != nil {
		return fmt.Errorf("failed to connect %q to bridge %v: %v", hostVethName, br.Attrs().Name, err)
	}

	// set hairpin mode
	if err = netlink.LinkSetHairpin(hostVeth, hairpinMode); err != nil {
		return fmt.Errorf("failed to setup hairpin mode for %v: %v", hostVethName, err)
	}

	return nil
}

func removeIfFromNSIfExists(netNs ns.NetNS, ifName string) error {
	return netNs.Do(func(_ ns.NetNS) error {
		l, err := netlink.LinkByName(ifName)
		if err != nil {
			if strings.Contains(err.Error(), "Link not found") {
				return nil
			}
			return err
		}
		return netlink.LinkDel(l)
	})
}

func createMacvlan(conf *NetConf, ifName string, netns ns.NetNS) error {
	mode, err := modeFromString(conf.Mode)
	if err != nil {
		return err
	}

	m, err := netlink.LinkByName(conf.Master)
	if err != nil {
		return fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
	}

	// due to kernel bug we have to create with tmpName or it might
	// collide with the name on the host and error out
	tmpName, err := ip.RandomVethName()
	if err != nil {
		return err
	}

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

	if err := netlink.LinkAdd(mv); err != nil {
		return fmt.Errorf("failed to create macvlan: %v", err)
	}

	return netns.Do(func(_ ns.NetNS) error {
		// TODO: duplicate following lines for ipv6 support, when it will be added in other places
		ipv4SysctlValueName := fmt.Sprintf(IPv4InterfaceArpProxySysctlTemplate, tmpName)
		if _, err := sysctl.Sysctl(ipv4SysctlValueName, "1"); err != nil {
			// remove the newly added link and ignore errors, because we already are in a failed state
			_ = netlink.LinkDel(mv)
			return fmt.Errorf("failed to set proxy_arp on newly added interface %q: %v", tmpName, err)
		}

		err := renameLink(tmpName, ifName)
		if err != nil {
			_ = netlink.LinkDel(mv)
			return fmt.Errorf("failed to rename macvlan to %q: %v", ifName, err)
		}
		return nil
	})
}

func createIpvlan(conf *NetConf, ifName string, netns ns.NetNS) error {
	mode, err := modeFromString(conf.Mode)
	if err != nil {
		return err
	}

	m, err := netlink.LinkByName(conf.Master)
	if err != nil {
		return fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
	}

	// due to kernel bug we have to create with tmpname or it might
	// collide with the name on the host and error out
	tmpName, err := ip.RandomVethName()
	if err != nil {
		return err
	}

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

	if err := netlink.LinkAdd(mv); err != nil {
		return fmt.Errorf("failed to create ipvlan: %v", err)
	}

	return netns.Do(func(_ ns.NetNS) error {
		err := renameLink(tmpName, ifName)
		if err != nil {
			return fmt.Errorf("failed to rename ipvlan to %q: %v", ifName, err)
		}
		return nil
	})
}

// SetupVeth sets up a virtual ethernet link.
// Should be in container netns, and will switch back to hostNS to set the host
// veth end up.
func SetupVeth(contVethName string, mtu int, hostNS ns.NetNS) (hostVeth, contVeth netlink.Link, err error) {
	var hostVethName string
	hostVethName, contVeth, err = makeVeth(contVethName, mtu)
	if err != nil {
		return
	}

	if err = netlink.LinkSetUp(contVeth); err != nil {
		err = fmt.Errorf("failed to set %q up: %v", contVethName, err)
		return
	}

	hostVeth, err = netlink.LinkByName(hostVethName)
	if err != nil {
		err = fmt.Errorf("failed to lookup %q: %v", hostVethName, err)
		return
	}

	if err = netlink.LinkSetNsFd(hostVeth, int(hostNS.Fd())); err != nil {
		err = fmt.Errorf("failed to move veth to host netns: %v", err)
		return
	}

	err = hostNS.Do(func(_ ns.NetNS) error {
		hostVeth, err := netlink.LinkByName(hostVethName)
		if err != nil {
			return fmt.Errorf("failed to lookup %q in %q: %v", hostVethName, hostNS.Path(), err)
		}

		if err = netlink.LinkSetUp(hostVeth); err != nil {
			return fmt.Errorf("failed to set %q up: %v", hostVethName, err)
		}
		return nil
	})
	return
}

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

		AfterEach(func() {
			Expect(targetNetNS.Close()).To(Succeed())
			Expect(originalNetNS.Close()).To(Succeed())
		})

		It("executes the callback within the target network namespace", func() {
			expectedInode, err := getInodeNS(targetNetNS)
			Expect(err).NotTo(HaveOccurred())

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

				actualInode, err := getInodeCurNetNS()
				Expect(err).NotTo(HaveOccurred())
				Expect(actualInode).To(Equal(expectedInode))
				return nil
			})
			Expect(err).NotTo(HaveOccurred())
		})

		It("provides the original namespace as the argument to the callback", func() {
			// Ensure we start in originalNetNS
			err := originalNetNS.Do(func(ns.NetNS) error {
				defer GinkgoRecover()

				origNSInode, err := getInodeNS(originalNetNS)
				Expect(err).NotTo(HaveOccurred())

				err = targetNetNS.Do(func(hostNS ns.NetNS) error {

		Expect(err).NotTo(HaveOccurred())
		defer targetNs.Close()

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

		// Execute the plugin with the ADD command, creating the veth endpoints
		err = originalNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			_, err := testutils.CmdAddWithResult(targetNs.Path(), IFNAME, func() error {
				return cmdAdd(args)
			})
			Expect(err).NotTo(HaveOccurred())
			return nil
		})
		Expect(err).NotTo(HaveOccurred())

		// Make sure ptp 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))
			return nil
		})

		Expect(err).NotTo(HaveOccurred())

		containerNetNS, err = ns.NewNS()
		Expect(err).NotTo(HaveOccurred())

		fakeBytes := make([]byte, 20)
		//to be reset in AfterEach block
		rand.Reader = bytes.NewReader(fakeBytes)

		_ = containerNetNS.Do(func(ns.NetNS) error {
			defer GinkgoRecover()

			hostVeth, containerVeth, err = ip.SetupVeth(fmt.Sprintf(ifaceFormatString, ifaceCounter), mtu, hostNetNS)
			if err != nil {
				return err
			}
			Expect(err).NotTo(HaveOccurred())

			hostVethName = hostVeth.Attrs().Name
			containerVethName = containerVeth.Attrs().Name

			return nil
		})
	})

	AfterEach(func() {
		Expect(containerNetNS.Close()).To(Succeed())
		Expect(hostNetNS.Close()).To(Succeed())
		ifaceCounter++
		rand.Reader = originalRandReader
	})

	})

	Context("when given a network namespace", func() {
		It("sets the lo device to UP", func() {
			command.Env = append(environ, fmt.Sprintf("CNI_COMMAND=%s", "ADD"))

			session, err := gexec.Start(command, GinkgoWriter, GinkgoWriter)
			Expect(err).NotTo(HaveOccurred())

			Eventually(session).Should(gbytes.Say(`{.*}`))
			Eventually(session).Should(gexec.Exit(0))

			var lo *net.Interface
			err = networkNS.Do(func(ns.NetNS) error {
				var err error
				lo, err = net.InterfaceByName("lo")
				return err
			})
			Expect(err).NotTo(HaveOccurred())

			Expect(lo.Flags & net.FlagUp).To(Equal(net.FlagUp))
		})

		It("sets the lo device to DOWN", func() {
			command.Env = append(environ, fmt.Sprintf("CNI_COMMAND=%s", "DEL"))

			session, err := gexec.Start(command, GinkgoWriter, GinkgoWriter)
			Expect(err).NotTo(HaveOccurred())

			Eventually(session).Should(gbytes.Say(``))
			Eventually(session).Should(gexec.Exit(0))

var _ = Describe("ipvlan Operations", func() {
	var originalNS ns.NetNS

	BeforeEach(func() {
		// Create a new NetNS so we don't modify the host
		var err error
		originalNS, err = ns.NewNS()
		Expect(err).NotTo(HaveOccurred())

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

			// Add master
			err = netlink.LinkAdd(&netlink.Dummy{
				LinkAttrs: netlink.LinkAttrs{
					Name: MASTER_NAME,
				},
			})
			Expect(err).NotTo(HaveOccurred())
			_, err = netlink.LinkByName(MASTER_NAME)
			Expect(err).NotTo(HaveOccurred())
			return nil
		})
		Expect(err).NotTo(HaveOccurred())
	})

	AfterEach(func() {
		Expect(originalNS.Close()).To(Succeed())
	})

	It("creates an ipvlan link in a non-default namespace", func() {
		conf := &NetConf{

				Name: "testConfig",
				Type: "bridge",
			},
			BrName: IFNAME,
			IsGW:   false,
			IPMasq: false,
			MTU:    5000,
		}

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

			bridge, err := setupBridge(conf)
			Expect(err).NotTo(HaveOccurred())
			Expect(bridge.Attrs().Name).To(Equal(IFNAME))

			// Double check that the link was added
			link, err := netlink.LinkByName(IFNAME)
			Expect(err).NotTo(HaveOccurred())
			Expect(link.Attrs().Name).To(Equal(IFNAME))
			return nil
		})
		Expect(err).NotTo(HaveOccurred())
	})

	It("handles an existing bridge", func() {
		const IFNAME = "bridge0"

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

func setupVF(conf *NetConf, ifName string, netns ns.NetNS) error {

	masterName := conf.Master
	vfIdx := conf.VF

	m, err := netlink.LinkByName(masterName)
	if err != nil {
		return fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
	}

	vfDir := fmt.Sprintf("/sys/class/net/%s/device/virtfn%d/net", masterName, vfIdx)
	if _, err := os.Lstat(vfDir); err != nil {
		return err
	}

	infos, err := ioutil.ReadDir(vfDir)
	if err != nil {
		return err
	}

	if len(infos) != 1 {
		return fmt.Errorf("Mutiple network devices in directory %s", vfDir)
	}

	// VF NIC name
	vfDevName := infos[0].Name()
	vfDev, err := netlink.LinkByName(vfDevName)
	if err != nil {
		return fmt.Errorf("failed to lookup vf device %q: %v", vfDevName, err)
	}

	// set hardware address
	if conf.MAC != "" {
		macAddr, err := net.ParseMAC(conf.MAC)
		if err != nil {
			return err
		}
		if err = netlink.LinkSetVfHardwareAddr(m, conf.VF, macAddr); err != nil {
			return fmt.Errorf("failed to set vf %d macaddress: %v", conf.VF, err)
		}
	}

	if conf.Vlan != 0 {
		if err = netlink.LinkSetVfVlan(m, conf.VF, conf.Vlan); err != nil {
			return fmt.Errorf("failed to set vf %d vlan: %v", conf.VF, err)
		}
	}

	if err = netlink.LinkSetUp(vfDev); err != nil {
		return fmt.Errorf("failed to setup vf %d device: %v", conf.VF, err)
	}

	// move VF device to ns
	if err = netlink.LinkSetNsFd(vfDev, int(netns.Fd())); err != nil {
		return fmt.Errorf("failed to move vf %d to netns: %v", conf.VF, err)
	}

	return netns.Do(func(_ ns.NetNS) error {
		err := renameLink(vfDevName, ifName)
		if err != nil {
			return fmt.Errorf("failed to rename vf %d device %q to %q: %v", conf.VF, vfDevName, ifName, err)
		}
		return nil
	})
}