flannel IPIP Mode

[BurlyLuo]

---
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: flannel
data:
  cni-conf.json: |
    {
      "name": "cbr0",
      "cniVersion": "0.3.1",
      "plugins": [
        {
          "type": "flannel",
          "delegate": {
            "hairpinMode": true,
            "isDefaultGateway": true
          }
        },
        {
          "type": "portmap",
          "capabilities": {
            "portMappings": true
          }
        }
      ]
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "ipip"
      }
    }
---

[BurlyLuo]

2. setup ipip with clab

#!/bin/bash
set -v
cat <<EOF>clab.yaml | clab deploy -t clab.yaml -
name: ipip
topology:
  nodes:
    gwx:
      kind: linux
      image: 192.168.2.100:5000/nettool
      exec:
      - ip a a 10.1.5.1/24 dev net1
      - ip a a 10.1.8.1/24 dev net2
      - ip a a 10.1.9.1/24 dev net3

    ipip1:
      kind: linux
      image: 192.168.2.100:5000/nettool
      exec:
      # add [node-gw] interface:eth1,eth2
      - ip a a 10.244.1.1/24 dev eth1
      - ip addr add 10.1.5.10/24 dev eth2
      # add ipip tunnel[lcoal 10.1.5.10 remote any.]
      - ip l a ipip0 type ipip local 10.1.5.10 dev eth2
      - ip a a 10.244.1.0/32 dev ipip0
      - ip l s ipip0 up
      # replace [node-gw] default gateway
      - ip route replace default via 10.1.5.1 dev eth2 
      # add dst_routing table
      - ip r a 10.244.2.0/24 via 10.1.8.10 dev ipip0 onlink
      - ip r a 10.244.3.0/24 via 10.1.9.10 dev ipip0 onlink

    ipip2:
      kind: linux
      image: 192.168.2.100:5000/nettool
      exec:
      - ip a a 10.244.2.1/24 dev eth1
      - ip addr add 10.1.8.10/24 dev eth2

      - ip l a ipip0 type ipip local 10.1.8.10 dev eth2
      - ip a a 10.244.2.0/32 dev ipip0
      - ip l s ipip0 up

      - ip route replace default via 10.1.8.1 dev eth2

      - ip r a 10.244.1.0/24 via 10.1.5.10 dev ipip0 onlink
      - ip r a 10.244.3.0/24 via 10.1.9.10 dev ipip0 onlink

    ipip3:
      kind: linux
      image: 192.168.2.100:5000/nettool
      exec:
      - ip a a 10.244.3.1/24 dev eth1
      - ip addr add 10.1.9.10/24 dev eth2

      - ip l a ipip0 type ipip local 10.1.9.10 dev eth2
      - ip a a 10.244.3.0/32 dev ipip0
      - ip l s ipip0 up

      - ip route replace default via 10.1.9.1 dev eth2

      - ip r a 10.244.1.0/24 via 10.1.5.10 dev ipip0 onlink
      - ip r a 10.244.2.0/24 via 10.1.8.10 dev ipip0 onlink

    server1:
      kind: linux
      image: 192.168.2.100:5000/nettool
      exec:
      - ip addr add 10.244.1.10/24 dev net0
      - ip route replace default via 10.244.1.1

    server2:
      kind: linux
      image: 192.168.2.100:5000/nettool
      exec:
      - ip addr add 10.244.2.10/24 dev net0
      - ip route replace default via 10.244.2.1

    server3:
      kind: linux
      image: 192.168.2.100:5000/nettool
      exec:
      - ip addr add 10.244.3.10/24 dev net0
      - ip route replace default via 10.244.3.1

  links:
    - endpoints: ["ipip1:eth1", "server1:net0"]
    - endpoints: ["ipip2:eth1", "server2:net0"]
    - endpoints: ["ipip3:eth1", "server3:net0"]
    - endpoints: ["ipip1:eth2", "gwx:net1"]
    - endpoints: ["ipip2:eth2", "gwx:net2"]
    - endpoints: ["ipip3:eth2", "gwx:net3"]
    
EOF