部署flannel的CNI插件与简单使用

flannel的部署

1.所有节点导入flannel镜像

$ wget https://github.com/flannel-io/flannel/releases/download/v0.26.4/flannel-v0.26.4-linux-amd64.tar.gz

根据所需前往github下载需要版本

$ docker load  -i oldboyedu-flannel-v1.6.2-v0.26.4.tar.gz 

2.编辑flannel资源清单

$ wget https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml


apiVersion: v1
kind: Namespace
metadata:
  labels:
    k8s-app: flannel
    pod-security.kubernetes.io/enforce: privileged
  name: kube-flannel
---
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: flannel
  name: flannel
  namespace: kube-flannel
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: flannel
  name: flannel
rules:
- apiGroups:
  - ""
  resources:
  - pods
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - nodes
  verbs:
  - get
  - list
  - watch
- apiGroups:
  - ""
  resources:
  - nodes/status
  verbs:
  - patch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: flannel
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-flannel
---
apiVersion: v1
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",
      "EnableNFTables": false,
      "Backend": {
        "Type": "vxlan"
      }
    }
kind: ConfigMap
metadata:
  labels:
    app: flannel
    k8s-app: flannel
    tier: node
  name: kube-flannel-cfg
  namespace: kube-flannel
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  labels:
    app: flannel
    k8s-app: flannel
    tier: node
  name: kube-flannel-ds
  namespace: kube-flannel
spec:
  selector:
    matchLabels:
      app: flannel
      k8s-app: flannel
  template:
    metadata:
      labels:
        app: flannel
        k8s-app: flannel
        tier: node
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/os
                operator: In
                values:
                - linux
      containers:
      - args:
        - --ip-masq
        - --kube-subnet-mgr
        command:
        - /opt/bin/flanneld
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        - name: EVENT_QUEUE_DEPTH
          value: "5000"
        image: ghcr.io/flannel-io/flannel:v0.26.4
        name: kube-flannel
        resources:
          requests:
            cpu: 100m
            memory: 50Mi
        securityContext:
          capabilities:
            add:
            - NET_ADMIN
            - NET_RAW
          privileged: false
        volumeMounts:
        - mountPath: /run/flannel
          name: run
        - mountPath: /etc/kube-flannel/
          name: flannel-cfg
        - mountPath: /run/xtables.lock
          name: xtables-lock
      hostNetwork: true
      initContainers:
      - args:
        - -f
        - /flannel
        - /opt/cni/bin/flannel
        command:
        - cp
        image: ghcr.io/flannel-io/flannel-cni-plugin:v1.6.2-flannel1
        name: install-cni-plugin
        volumeMounts:
        - mountPath: /opt/cni/bin
          name: cni-plugin
      - args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        command:
        - cp
        image: ghcr.io/flannel-io/flannel:v0.26.4
        name: install-cni
        volumeMounts:
        - mountPath: /etc/cni/net.d
          name: cni
        - mountPath: /etc/kube-flannel/
          name: flannel-cfg
      priorityClassName: system-node-critical
      serviceAccountName: flannel
      tolerations:
      - effect: NoSchedule
        operator: Exists
      volumes:
      - hostPath:
          path: /run/flannel
        name: run
      - hostPath:
          path: /opt/cni/bin
        name: cni-plugin
      - hostPath:
          path: /etc/cni/net.d
        name: cni
      - configMap:
          name: kube-flannel-cfg
        name: flannel-cfg
      - hostPath:
          path: /run/xtables.lock
          type: FileOrCreate
        name: xtables-lock

3. 部署flannel组件

$ kubectl apply -f kube-flannel.yml

验证flannel是否部署成功

1. 查看flannel运行状态

$ kubectl get pods -o wide -n kube-flannel
NAME                    READY   STATUS    RESTARTS   AGE   IP           NODE        NOMINATED NODE   READINESS GATES
kube-flannel-ds-flnbm   1/1     Running   0          34s   10.0.0.231   master231   <none>           <none>
kube-flannel-ds-s4vp6   1/1     Running   0          34s   10.0.0.233   worker233   <none>           <none>
kube-flannel-ds-x6gv8   1/1     Running   0          34s   10.0.0.232   worker232   <none>           <none>

2. cni0网卡重建（手动创建重启机器后会丢失配置，最好是开机自动巡检。）

如果有节点没有cni0网卡，建议大家手动创建相应的网桥设备，但是注意网段要一致

- 手动创建cni0网卡

---> 假设 master231的flannel.1是10.244.0.0网段。
$ ip link add cni0 type bridge
$ ip link set dev cni0 up
$ ip addr add 10.244.0.1/24 dev cni0


---> 假设 worker232的flannel.1是10.244.1.0网段。
$ ip link add cni0 type bridge
$ ip link set dev cni0 up
$ ip addr add 10.244.1.1/24 dev cni0

---> 假设 worker233的flannel.1是10.244.2.0网段。
$ ip link add cni0 type bridge
$ ip link set dev cni0 up
$ ip addr add 10.244.2.1/24 dev cni0

3. 验证Pod的CNI网络是否正常

用k8s部署个nginx
跑起来后查看容器ip
curl 容器ip
是否能够访问