pod_linux.go

// +build linux

package plugin

import (
	"fmt"
	"strconv"
	"syscall"

	sdnapi "github.com/openshift/origin/pkg/sdn/apis/network"
	"github.com/openshift/origin/pkg/sdn/plugin/cniserver"
	"github.com/openshift/origin/pkg/util/ipcmd"

	"github.com/golang/glog"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	kerrors "k8s.io/apimachinery/pkg/util/errors"
	kapi "k8s.io/kubernetes/pkg/api"
	kapiv1 "k8s.io/kubernetes/pkg/api/v1"
	kcontainer "k8s.io/kubernetes/pkg/kubelet/container"
	knetwork "k8s.io/kubernetes/pkg/kubelet/network"
	"k8s.io/kubernetes/pkg/kubelet/network/hostport"
	kbandwidth "k8s.io/kubernetes/pkg/util/bandwidth"
	kexec "k8s.io/kubernetes/pkg/util/exec"

	"github.com/containernetworking/cni/pkg/invoke"
	"github.com/containernetworking/cni/pkg/ip"
	"github.com/containernetworking/cni/pkg/ipam"
	"github.com/containernetworking/cni/pkg/ns"
	cnitypes "github.com/containernetworking/cni/pkg/types"

	"github.com/vishvananda/netlink"
)

const (
	podInterfaceName = knetwork.DefaultInterfaceName
)

// For a given container, returns host veth name, container veth MAC, and pod IP
func getVethInfo(netns, containerIfname string) (string, string, string, error) {
	var (
		peerIfindex int
		contVeth    netlink.Link
		err         error
		podIP       string
	)

	containerNs, err := ns.GetNS(netns)
	if err != nil {
		return "", "", "", fmt.Errorf("failed to get container netns: %v", err)
	}
	defer containerNs.Close()

	err = containerNs.Do(func(ns.NetNS) error {
		contVeth, err = netlink.LinkByName(containerIfname)
		if err != nil {
			return err
		}
		peerIfindex = contVeth.Attrs().ParentIndex

		addrs, err := netlink.AddrList(contVeth, syscall.AF_INET)
		if err != nil {
			return fmt.Errorf("failed to get container IP addresses: %v", err)
		}
		if len(addrs) == 0 {
			return fmt.Errorf("container had no addresses")
		}
		podIP = addrs[0].IP.String()

		return nil
	})
	if err != nil {
		return "", "", "", fmt.Errorf("failed to inspect container interface: %v", err)
	}

	hostVeth, err := netlink.LinkByIndex(peerIfindex)
	if err != nil {
		return "", "", "", fmt.Errorf("failed to get host veth: %v", err)
	}

	return hostVeth.Attrs().Name, contVeth.Attrs().HardwareAddr.String(), podIP, nil
}

// Adds a macvlan interface to a container, if requested, for use with the egress router feature
func maybeAddMacvlan(pod *kapi.Pod, netns string) error {
	val, ok := pod.Annotations[sdnapi.AssignMacvlanAnnotation]
	if !ok || val != "true" {
		return nil
	}

	privileged := false
	for _, container := range append(pod.Spec.Containers, pod.Spec.InitContainers...) {
		if container.SecurityContext != nil && container.SecurityContext.Privileged != nil && *container.SecurityContext.Privileged {
			privileged = true
			break
		}
	}
	if !privileged {
		return fmt.Errorf("pod has %q annotation but is not privileged", sdnapi.AssignMacvlanAnnotation)
	}

	// Find interface with the default route
	var defIface netlink.Link
	routes, err := netlink.RouteList(nil, netlink.FAMILY_V4)
	if err != nil {
		return fmt.Errorf("failed to read routes: %v", err)
	}

	for _, r := range routes {
		if r.Dst == nil {
			defIface, err = netlink.LinkByIndex(r.LinkIndex)
			if err != nil {
				return fmt.Errorf("failed to get default route interface: %v", err)
			}
		}
	}
	if defIface == nil {
		return fmt.Errorf("failed to find default route interface")
	}

	podNs, err := ns.GetNS(netns)
	if err != nil {
		return fmt.Errorf("could not open netns %q", netns)
	}
	defer podNs.Close()

	err = netlink.LinkAdd(&netlink.Macvlan{
		LinkAttrs: netlink.LinkAttrs{
			MTU:         defIface.Attrs().MTU,
			Name:        "macvlan0",
			ParentIndex: defIface.Attrs().Index,
			Namespace:   netlink.NsFd(podNs.Fd()),
		},
		Mode: netlink.MACVLAN_MODE_PRIVATE,
	})
	if err != nil {
		return fmt.Errorf("failed to create macvlan interface: %v", err)
	}
	return podNs.Do(func(netns ns.NetNS) error {
		l, err := netlink.LinkByName("macvlan0")
		if err != nil {
			return fmt.Errorf("failed to find macvlan interface: %v", err)
		}
		err = netlink.LinkSetUp(l)
		if err != nil {
			return fmt.Errorf("failed to set macvlan interface up: %v", err)
		}
		return nil
	})
}

func createIPAMArgs(netnsPath string, action cniserver.CNICommand, id string) *invoke.Args {
	return &invoke.Args{
		Command:     string(action),
		ContainerID: id,
		NetNS:       netnsPath,
		IfName:      podInterfaceName,
		Path:        "/opt/cni/bin",
	}
}

// Run CNI IPAM allocation for the container and return the allocated IP address
func (m *podManager) ipamAdd(netnsPath string, id string) (*cnitypes.Result, error) {
	if netnsPath == "" {
		return nil, fmt.Errorf("netns required for CNI_ADD")
	}

	args := createIPAMArgs(netnsPath, cniserver.CNI_ADD, id)
	result, err := invoke.ExecPluginWithResult("/opt/cni/bin/host-local", m.ipamConfig, args)
	if err != nil {
		return nil, fmt.Errorf("failed to run CNI IPAM ADD: %v", err)
	}

	if result.IP4 == nil {
		return nil, fmt.Errorf("failed to obtain IP address from CNI IPAM")
	}

	return result, nil
}

// Run CNI IPAM release for the container
func (m *podManager) ipamDel(id string) error {
	args := createIPAMArgs("", cniserver.CNI_DEL, id)
	err := invoke.ExecPluginWithoutResult("/opt/cni/bin/host-local", m.ipamConfig, args)
	if err != nil {
		return fmt.Errorf("failed to run CNI IPAM DEL: %v", err)
	}
	return nil
}

func setupPodBandwidth(ovs *ovsController, pod *kapi.Pod, hostVeth string) error {
	ingressVal, egressVal, err := kbandwidth.ExtractPodBandwidthResources(pod.Annotations)
	if err != nil {
		return fmt.Errorf("failed to parse pod bandwidth: %v", err)
	}

	ingressBPS := int64(-1)
	egressBPS := int64(-1)
	if ingressVal != nil {
		ingressBPS = ingressVal.Value()

		// FIXME: doesn't seem possible to do this with the netlink library?
		itx := ipcmd.NewTransaction(kexec.New(), hostVeth)
		itx.SetLink("qlen", "1000")
		err = itx.EndTransaction()
		if err != nil {
			return err
		}
	}
	if egressVal != nil {
		egressBPS = egressVal.Value()
	}

	return ovs.SetPodBandwidth(hostVeth, ingressBPS, egressBPS)
}

func vnidToString(vnid uint32) string {
	return strconv.FormatUint(uint64(vnid), 10)
}

// podIsExited returns true if the pod is exited (all containers inside are exited).
func podIsExited(p *kcontainer.Pod) bool {
	for _, c := range p.Containers {
		if c.State != kcontainer.ContainerStateExited {
			return false
		}
	}
	return true
}

// Set up all networking (host/container veth, OVS flows, IPAM, loopback, etc)
func (m *podManager) setup(req *cniserver.PodRequest) (*cnitypes.Result, *runningPod, error) {
	pod, err := m.kClient.Core().Pods(req.PodNamespace).Get(req.PodName, metav1.GetOptions{})
	if err != nil {
		return nil, nil, err
	}

	ipamResult, err := m.ipamAdd(req.Netns, req.SandboxID)
	if err != nil {
		return nil, nil, fmt.Errorf("failed to run IPAM for %v: %v", req.SandboxID, err)
	}
	podIP := ipamResult.IP4.IP.IP

	// Release any IPAM allocations and hostports if the setup failed
	var success bool
	defer func() {
		if !success {
			m.ipamDel(req.SandboxID)
			if err := m.hostportSyncer.SyncHostports(TUN, m.getRunningPods()); err != nil {
				glog.Warningf("failed syncing hostports: %v", err)
			}
		}
	}()

	// Open any hostports the pod wants
	var v1Pod kapiv1.Pod
	if err := kapiv1.Convert_api_Pod_To_v1_Pod(pod, &v1Pod, nil); err != nil {
		return nil, nil, err
	}
	podPortMapping := hostport.ConstructPodPortMapping(&v1Pod, podIP)
	if err := m.hostportSyncer.OpenPodHostportsAndSync(podPortMapping, TUN, m.getRunningPods()); err != nil {
		return nil, nil, err
	}

	var hostVethName, contVethMac string
	err = ns.WithNetNSPath(req.Netns, func(hostNS ns.NetNS) error {
		hostVeth, contVeth, err := ip.SetupVeth(podInterfaceName, int(m.mtu), hostNS)
		if err != nil {
			return fmt.Errorf("failed to create container veth: %v", err)
		}
		// Force a consistent MAC address based on the IP address
		if err := ip.SetHWAddrByIP(podInterfaceName, podIP, nil); err != nil {
			return fmt.Errorf("failed to set pod interface MAC address: %v", err)
		}
		// refetch to get hardware address and other properties
		contVeth, err = netlink.LinkByIndex(contVeth.Attrs().Index)
		if err != nil {
			return fmt.Errorf("failed to fetch container veth: %v", err)
		}
		// Clear out gateway to prevent ConfigureIface from adding the cluster
		// subnet via the gateway
		ipamResult.IP4.Gateway = nil
		if err = ipam.ConfigureIface(podInterfaceName, ipamResult); err != nil {
			return fmt.Errorf("failed to configure container IPAM: %v", err)
		}

		lo, err := netlink.LinkByName("lo")
		if err == nil {
			err = netlink.LinkSetUp(lo)
		}
		if err != nil {
			return fmt.Errorf("failed to configure container loopback: %v", err)
		}

		hostVethName = hostVeth.Attrs().Name
		contVethMac = contVeth.Attrs().HardwareAddr.String()
		return nil
	})
	if err != nil {
		return nil, nil, err
	}

	vnid, err := m.policy.GetVNID(req.PodNamespace)
	if err != nil {
		return nil, nil, err
	}

	if err := maybeAddMacvlan(pod, req.Netns); err != nil {
		return nil, nil, err
	}

	ofport, err := m.ovs.SetUpPod(hostVethName, podIP.String(), contVethMac, req.SandboxID, vnid)
	if err != nil {
		return nil, nil, err
	}
	if err := setupPodBandwidth(m.ovs, pod, hostVethName); err != nil {
		return nil, nil, err
	}

	m.policy.EnsureVNIDRules(vnid)
	success = true
	return ipamResult, &runningPod{podPortMapping: podPortMapping, vnid: vnid, ofport: ofport}, nil
}

// Update OVS flows when something (like the pod's namespace VNID) changes
func (m *podManager) update(req *cniserver.PodRequest) (uint32, error) {
	vnid, err := m.policy.GetVNID(req.PodNamespace)
	if err != nil {
		return 0, err
	}

	if err := m.ovs.UpdatePod(req.SandboxID, vnid); err != nil {
		return 0, err
	}
	return vnid, nil
}

// Clean up all pod networking (clear OVS flows, release IPAM lease, remove host/container veth)
func (m *podManager) teardown(req *cniserver.PodRequest) error {
	errList := []error{}

	netnsValid := true
	if err := ns.IsNSorErr(req.Netns); err != nil {
		if _, ok := err.(ns.NSPathNotExistErr); ok {
			glog.V(3).Infof("teardown called on already-destroyed pod %s/%s; only cleaning up IPAM", req.PodNamespace, req.PodName)
			netnsValid = false
		}
	}

	if netnsValid {
		hostVethName, _, podIP, err := getVethInfo(req.Netns, podInterfaceName)
		if err != nil {
			return err
		}

		if err := m.ovs.TearDownPod(hostVethName, podIP); err != nil {
			errList = append(errList, err)
		}
	}

	if err := m.ipamDel(req.SandboxID); err != nil {
		errList = append(errList, err)
	}

	if err := m.hostportSyncer.SyncHostports(TUN, m.getRunningPods()); err != nil {
		errList = append(errList, err)
	}

	return kerrors.NewAggregate(errList)
}