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Flannel

  • flannel-io/flannel
    • layer 2
    • overlay network
    • 每个节点一个 CIDR 段
  • 支持后端
    • vxlan
      • 大多时候默认
      • DirectRouting 可以在相同 subnet 时直连 - 类似 host-gw
    • host-gw
      • 性能更好 - ip ro add 的方式添加路由
      • 需要 2 层直连 - TincVPN, n2n 可以
  • 执行方式
  • flanneld
    • 每个节点上执行一个 daemon
# kube-flannel - vxlan
# https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

vxlan​

{
  "Network": "10.50.0.0/16",
  "Backend": {
    "Type": "extension",
    "PreStartupCommand": "export VNI=1; export IF_NAME=flannel-vxlan; ip link del $IF_NAME 2>/dev/null; ip link add $IF_NAME type vxlan id $VNI dstport 8472 nolearning && ip link set mtu 1450 dev $IF_NAME && cat /sys/class/net/$IF_NAME/address",
    "PostStartupCommand": "export IF_NAME=flannel-vxlan; export SUBNET_IP=`echo $SUBNET | cut -d'/' -f 1`; ip addr add $SUBNET_IP/32 dev $IF_NAME && ip link set $IF_NAME up",
    "ShutdownCommand": "export IF_NAME=flannel-vxlan; ip link del $IF_NAME",
    "SubnetAddCommand": "export SUBNET_IP=`echo $SUBNET | cut -d'/' -f 1`; export IF_NAME=flannel-vxlan; read VTEP; ip route add $SUBNET nexthop via $SUBNET_IP dev $IF_NAME onlink && arp -s $SUBNET_IP $VTEP dev $IF_NAME && bridge fdb add $VTEP dev $IF_NAME self dst $PUBLIC_IP"
  }
}

host-gw​

{
  "Network": "10.50.0.0/16",
  "Backend": {
    "Type": "extension",
    "SubnetAddCommand": "ip route add $SUBNET via $PUBLIC_IP",
    "SubnetRemoveCommand": "ip route del $SUBNET via $PUBLIC_IP"
  }
}

wireguard​

{
  "Network": "10.50.0.0/16",
  "Backend": {
    "Type": "extension",
    "PreStartupCommand": "wg genkey | tee privatekey | wg pubkey",
    "PostStartupCommand": "export SUBNET_IP=`echo $SUBNET | cut -d'/' -f 1`; ip link del flannel-wg 2>/dev/null; ip link add flannel-wg type wireguard && wg set flannel-wg listen-port 51820 private-key privatekey && ip addr add $SUBNET_IP/32 dev flannel-wg && ip link set flannel-wg up && ip route add $NETWORK dev flannel-wg",
    "ShutdownCommand": "ip link del flannel-wg",
    "SubnetAddCommand": "read PUBLICKEY; wg set flannel-wg peer $PUBLICKEY endpoint $PUBLIC_IP:51820 allowed-ips $SUBNET",
    "SubnetRemoveCommand": "read PUBLICKEY; wg set flannel-wg peer $PUBLICKEY remove"
  }
}