Implement the node side of automatic egress IP support

pkg/network/node/egressip.go

@@ -0,0 +1,300 @@
+package node
+
+import (
+	"fmt"
+	"net"
+	"sync"
+	"syscall"
+
+	"github.com/golang/glog"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+	utilwait "k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/tools/cache"
+
+	osclient "github.com/openshift/origin/pkg/client"
+	networkapi "github.com/openshift/origin/pkg/network/apis/network"
+	"github.com/openshift/origin/pkg/network/common"
+
+	"github.com/vishvananda/netlink"
+)
+
+type nodeEgress struct {
+	nodeIP    string
+	egressIPs sets.String
+}
+
+type namespaceEgress struct {
+	vnid uint32
+
+	// claimedIP is the egress IP it wants (NetNamespace.EgressIP[0]), or "" for none
+	claimedIP string
+	// assignedIP is an egress IP actually in use on nodeIP
+	assignedIP string
+	nodeIP     string
+}
+
+type egressIPWatcher struct {
+	sync.Mutex
+
+	localIP string
+	oc      *ovsController
+
+	osClient *osclient.Client
+	iptables *NodeIPTables
+
+	// from HostSubnets
+	nodesByNodeIP   map[string]*nodeEgress
+	nodesByEgressIP map[string]*nodeEgress
+
+	// From NetNamespaces
+	namespacesByVNID     map[uint32]*namespaceEgress
+	namespacesByEgressIP map[string]*namespaceEgress
+
+	localEgressLink      netlink.Link
+	localEgressIPMaskLen int
+
+	testModeChan chan string
+}
+
+func newEgressIPWatcher(localIP string, oc *ovsController) *egressIPWatcher {
+	return &egressIPWatcher{
+		localIP: localIP,
+		oc:      oc,
+
+		nodesByNodeIP:   make(map[string]*nodeEgress),
+		nodesByEgressIP: make(map[string]*nodeEgress),
+
+		namespacesByVNID:     make(map[uint32]*namespaceEgress),
+		namespacesByEgressIP: make(map[string]*namespaceEgress),
+	}
+}
+
+func (eip *egressIPWatcher) Start(osClient *osclient.Client, iptables *NodeIPTables) error {
+	eip.iptables = iptables
+	eip.osClient = osClient
+
+	go utilwait.Forever(eip.watchHostSubnets, 0)
+	go utilwait.Forever(eip.watchNetNamespaces, 0)
+	return nil
+}
+
+func ipToHex(ip string) string {
+	bytes := net.ParseIP(ip)
+	if bytes == nil {
+		return "invalid IP: shouldn't happen"
+	}
+	bytes = bytes.To4()
+	return fmt.Sprintf("0x%02x%02x%02x%02x", bytes[0], bytes[1], bytes[2], bytes[3])
+}
+
+func (eip *egressIPWatcher) watchHostSubnets() {
+	common.RunEventQueue(eip.osClient, common.HostSubnets, func(delta cache.Delta) error {
+		hs := delta.Object.(*networkapi.HostSubnet)
+
+		var egressIPs []string
+		if delta.Type != cache.Deleted {
+			egressIPs = hs.EgressIPs
+		}
+
+		eip.updateNode(hs.HostIP, egressIPs)
+		return nil
+	})
+}
+
+func (eip *egressIPWatcher) updateNode(nodeIP string, nodeEgressIPs []string) {
+	eip.Lock()
+	defer eip.Unlock()
+
+	node := eip.nodesByNodeIP[nodeIP]
+	if node == nil {
+		if len(nodeEgressIPs) == 0 {
+			return
+		}
+		node = &nodeEgress{nodeIP: nodeIP, egressIPs: sets.NewString()}
+		eip.nodesByNodeIP[nodeIP] = node
+	} else if len(nodeEgressIPs) == 0 {
+		delete(eip.nodesByNodeIP, nodeIP)
+	}
+	oldEgressIPs := node.egressIPs
+	node.egressIPs = sets.NewString(nodeEgressIPs...)
+
+	// Process new EgressIPs
+	for _, ip := range node.egressIPs.Difference(oldEgressIPs).UnsortedList() {
+		eip.nodesByEgressIP[ip] = node
+		hex := ipToHex(ip)
+
+		if nodeIP == eip.localIP {
+			if err := eip.claimEgressIP(ip, hex); err != nil {
+				glog.Errorf("Error claiming Egress IP %q: %v", ip, err)
+			}
+		}
+
+		if ns, exists := eip.namespacesByEgressIP[ip]; exists {
+			if ns.assignedIP == "" {
+				ns.assignedIP = ip
+				ns.nodeIP = nodeIP
+				err := eip.oc.UpdateNamespaceEgressRules(ns.vnid, ns.nodeIP, hex)
+				if err != nil {
+					glog.Errorf("Error updating Namespace egress rules: %v", err)
+				}
+			}
+		}
+	}
+
+	// Process removed EgressIPs
+	for _, ip := range oldEgressIPs.Difference(node.egressIPs).UnsortedList() {
+		delete(eip.nodesByEgressIP, ip)
+		hex := ipToHex(ip)
+
+		if nodeIP == eip.localIP {
+			if err := eip.releaseEgressIP(ip, hex); err != nil {
+				glog.Errorf("Error releasing Egress IP %q: %v", ip, err)
+			}
+		}
+
+		if ns, exists := eip.namespacesByEgressIP[ip]; exists {
+			if ns.assignedIP == ip {
+				ns.assignedIP = ""
+				ns.nodeIP = ""
+				err := eip.oc.UpdateNamespaceEgressRules(ns.vnid, "", hex)
+				if err != nil {
+					glog.Errorf("Error updating Namespace egress rules: %v", err)
+				}
+			}
+		}
+	}
+}
+
+func (eip *egressIPWatcher) watchNetNamespaces() {
+	common.RunEventQueue(eip.osClient, common.NetNamespaces, func(delta cache.Delta) error {
+		netns := delta.Object.(*networkapi.NetNamespace)
+
+		var egressIP string
+		if delta.Type != cache.Deleted && len(netns.EgressIPs) != 0 {
+			egressIP = netns.EgressIPs[0]
+		}
+
+		eip.updateNamespace(netns.NetID, egressIP)
+		return nil
+	})
+}
+
+func (eip *egressIPWatcher) updateNamespace(vnid uint32, egressIP string) {
+	eip.Lock()
+	defer eip.Unlock()
+
+	ns := eip.namespacesByVNID[vnid]
+	if ns == nil {
+		if egressIP == "" {
+			return
+		}
+		ns = &namespaceEgress{vnid: vnid}
+		eip.namespacesByVNID[vnid] = ns
+	}
+	if ns.claimedIP == egressIP {
+		return
+	}
+
+	if ns.claimedIP != "" {
+		delete(eip.namespacesByEgressIP, ns.claimedIP)
+		ns.assignedIP = ""
+		ns.nodeIP = ""
+	}
+	ns.claimedIP = egressIP
+	eip.namespacesByEgressIP[egressIP] = ns
+	if node := eip.nodesByEgressIP[egressIP]; node != nil {
+		ns.assignedIP = egressIP
+		ns.nodeIP = node.nodeIP
+	}
+
+	egressHex := ""
+	if egressIP != "" {
+		egressHex = ipToHex(egressIP)
+	}
+
+	err := eip.oc.UpdateNamespaceEgressRules(ns.vnid, ns.nodeIP, egressHex)
+	if err != nil {
+		glog.Errorf("Error updating Namespace egress rules: %v", err)
+	}
+}
+
+func (eip *egressIPWatcher) claimEgressIP(egressIP, egressHex string) error {
+	if eip.testModeChan != nil {
+		eip.testModeChan <- fmt.Sprintf("claim %s", egressIP)
+		return nil
+	}
+
+	if eip.localEgressLink == nil {
+		links, err := netlink.LinkList()
+		if err != nil {
+			return fmt.Errorf("could not get list of network interfaces while adding egress IP: %v", err)
+		}
+	linkLoop:
+		for _, link := range links {
+			addrs, err := netlink.AddrList(link, syscall.AF_INET)
+			if err != nil {
+				return fmt.Errorf("could not get addresses of interface %q while adding egress IP: %v", link.Attrs().Name, err)
+			}
+
+			for _, addr := range addrs {
+				if addr.IP.String() == eip.localIP {
+					eip.localEgressLink = link
+					eip.localEgressIPMaskLen, _ = addr.Mask.Size()
+					break linkLoop
+				}
+			}
+		}
+
+		if eip.localEgressLink == nil {
+			return fmt.Errorf("could not find network interface with the address %q while adding egress IP", eip.localIP)
+		}
+	}
+
+	egressIPNet := fmt.Sprintf("%s/%d", egressIP, eip.localEgressIPMaskLen)
+	addr, err := netlink.ParseAddr(egressIPNet)
+	if err != nil {
+		return fmt.Errorf("could not parse egress IP %q: %v", egressIPNet, err)
+	}
+	err = netlink.AddrAdd(eip.localEgressLink, addr)
+	if err != nil {
+		return fmt.Errorf("could not add egress IP %q to %s: %v", egressIPNet, eip.localEgressLink.Attrs().Name, err)
+	}
+
+	if err := eip.iptables.AddEgressIPRules(egressIP, egressHex); err != nil {
+		return fmt.Errorf("could not add egress IP iptables rule: %v", err)
+	}
+
+	return nil
+}
+
+func (eip *egressIPWatcher) releaseEgressIP(egressIP, egressHex string) error {
+	if eip.testModeChan != nil {
+		eip.testModeChan <- fmt.Sprintf("release %s", egressIP)
+		return nil
+	}
+
+	if eip.localEgressLink == nil {
+		return nil
+	}
+
+	egressIPNet := fmt.Sprintf("%s/%d", egressIP, eip.localEgressIPMaskLen)
+	addr, err := netlink.ParseAddr(egressIPNet)
+	if err != nil {
+		return fmt.Errorf("could not parse egress IP %q: %v", egressIPNet, err)
+	}
+	err = netlink.AddrDel(eip.localEgressLink, addr)
+	if err != nil {
+		if err == syscall.EADDRNOTAVAIL {
+			glog.V(2).Infof("Could not delete egress IP %q from %s: no such address", egressIPNet, eip.localEgressLink.Attrs().Name)
+		} else {
+			return fmt.Errorf("could not delete egress IP %q from %s: %v", egressIPNet, eip.localEgressLink.Attrs().Name, err)
+		}
+	}
+
+	if err := eip.iptables.DeleteEgressIPRules(egressIP, egressHex); err != nil {
+		return fmt.Errorf("could not delete egress IP iptables rule: %v", err)
+	}
+
+	return nil
+}