// backend/vxlan/vxlan.go

func (be *VXLANBackend) RegisterNetwork(ctx context.Context, network string, config *subnet.Config) (backend.Network, error)

  • 创建cfg变量,它的结构体中包含VIN int, Port int, GBP bool三个字段,其中VNI设置为默认的defaultVNI = 1,并且调用json.Unmarshal(config.Backend, &cfg)解析
  • 创建变量devAttrs := vxlanDeviceAttrs{

    vni:      uint32(cfg.VNI),

    name:      fmt.Sprintf("flannel.%v", cfg.VNI),

    vtepIndex:   be.extIface.Iface.Index,

    vtepAddr:   be.extIface.IfaceAddr,

    vtepPort:    cfg.Port,

    gbp:       cfg.GBP,

  }

  • 调用dev, err := newVXLANDevice(&devAttrs) ---> 调用netlink库添加vlan设备,并且可以处理设备已经存在的情况
  • 调用subnetAttrs, err := newSubnetAttrs(be.extIface.ExtAddr, dev.MACAddr())
  • 调用lease, err := be.subnetMgr.AcquireLease(ctx, network, subnetAttrs)
  • 创建vxlanNet := ip.IP4Net{

    IP:      lease.Subnet.IP,

    PrefixLen:   config.Network.PrefixLen,

  }

  • 调用err = dev.Configure(vxlanNet)
  • 最后return newNetwork(network, be.subnetMgr, be.extIface, dev, vxlanNet, lease)

// backend/vxlan/vxlan.go

func newSubnetAttrs(publicIP net.IP, mac net.HardwareAddr)

  • 首先调用data, err := json.Marshal(&vxlanLeaseAttrs{hardwarAddr(mac)})
  • 接着调用return &subnet.LeaseAttrs{

    PublicIP:    ip.FromIP(publicIP),

    BackendType:  "vxlan",

    BackendData:  json.RawMessage(data),

  }

// backend/vxlan/device.go

func (dev *vxlanDevice)  Configure(ipn ip.IP4Net) error

  • 调用setAddr4(dev.link, ipn.ToIPNet())
  • 调用netlink.LinkSetUp(dev.link)启动VTEP
  • 最后添加一条路由 route := netlink.Route{

    LinkIndex:    dev.link.Attrs().Index,

    Scope:      netlink.SCOPE_UNIVERSE,

    Dst:        ipn.Network().ToIPNet(),

  },再调用netlink.RouteAdd(&route)

// backend/vxlan/network.go

func newNetwork(name string, subnetMgr subnet.Manager, extIface *backend.ExternalInterface, dev *vxlanDevice, _ ip.IP4Net, lease *subnet.Lease) (*network, error)

该函数仅仅用参数填充network数据结构:

nw := &network {

  SimpleNetwork:  backend.SimpleNetwork{

    SubnetLease:  lease,

    ExtIface:     extIface,

  },

  name:     name,

  subnetMgr:    subnetMgr,

  dev:      dev,

}

network数据结构如下所示:

type network struct {
  backend.SimpleNetwork
  name    string
  extIface   *backend.ExternalInterface
  dev     *vxlanDevice
  routes    routes
  subnetMgr  subnet.Manager
}

  

// backend/vxlan/network.go

func (nw *network) Run(ctx context.Context)

  • 创建misses := make(chan *netlink.Neigh, 100)并调用go nw.dev.MonitorMisses(misses)
  • 创建events := make(chan []subnet.Event)并调用go subnet.WatchLeases(ctx, nw.subnetMgr, nw.name, nw.SubnetLease, events)
  • 调用select,如果事件类型为initialEventsBatch,调用nw.handleInitialSubnetEvents(initialEventsBatch)直到成功为止
  • 一个无限的for循环,当misses有事件发生时,调用nw.handleMiss(miss),events有事件发生时,调用nw.handleSubnetEvents(evtBatch)
05-13 12:45