八、安装flannel集群网络

1、安装cni插件

二进制包下载地址：https://github.com/containernetworking/plugins/releases

[root@k8s-master01 node]# mkdir cni/bin -p
[root@k8s-master01 node]# tar xf cni-plugins-linux-amd64-v0.8.2.tgz -C cni/bin/
[root@k8s-master01 node]# scp -r cni k8s-node01:/opt/
[root@k8s-master01 node]# scp -r cni k8s-node02:/opt/
[root@k8s-master01 node]# scp -r cni k8s-node03:/opt/

#mkdir -p /etc/cni/net.d
[root@k8s-node01 ~]# ls /etc/cni/
net.d
[root@k8s-node02 ~]# ls /etc/cni/
net.d
[root@k8s-node03 ~]# ls /etc/cni/
net.d

2、部署flannel

文档说明

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/

kube-flannel.yaml文件

[root@k8s-master01 ~]# cat kube-flannel.yaml
---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: psp.flannel.unprivileged
  annotations:
    seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
    seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
    apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
    apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
  privileged: false
  volumes:
    - configMap
    - secret
    - emptyDir
    - hostPath
  allowedHostPaths:
    - pathPrefix: "/etc/cni/net.d"
    - pathPrefix: "/etc/kube-flannel"
    - pathPrefix: "/run/flannel"
  readOnlyRootFilesystem: false
  # Users and groups
  runAsUser:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  fsGroup:
    rule: RunAsAny
  # Privilege Escalation
  allowPrivilegeEscalation: false
  defaultAllowPrivilegeEscalation: false
  # Capabilities
  allowedCapabilities: ['NET_ADMIN']
  defaultAddCapabilities: []
  requiredDropCapabilities: []
  # Host namespaces
  hostPID: false
  hostIPC: false
  hostNetwork: true
  hostPorts:
  - min: 0
    max: 65535
  # SELinux
  seLinux:
    # SELinux is unsed in CaaSP
    rule: 'RunAsAny'
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: flannel
rules:
  - apiGroups: ['extensions']
    resources: ['podsecuritypolicies']
    verbs: ['use']
    resourceNames: ['psp.flannel.unprivileged']
  - apiGroups:
      - ""
    resources:
      - pods
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes/status
    verbs:
      - patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: flannel
  namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: flannel
data:
  cni-conf.json: |
    {
      "cniVersion": "0.2.0",
      "name": "cbr0",
      "plugins": [
        {
          "type": "flannel",
          "delegate": {
            "hairpinMode": true,
            "isDefaultGateway": true
          }
        },
        {
          "type": "portmap",
          "capabilities": {
            "portMappings": true
          }
        }
      ]
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-amd64
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: beta.kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: beta.kubernetes.io/arch
                    operator: In
                    values:
                      - amd64
      hostNetwork: true
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: lizhenliang/flannel:v0.11.0-amd64 
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: lizhenliang/flannel:v0.11.0-amd64 
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg

部署，会在每一个Node上面启动一个容器：

[root@k8s-master01 yaml]# kubectl apply -f kube-flannel.yaml 

查看：

[root@k8s-master01 yaml]# kubectl get pods -n kube-system -o wide
NAME                          READY   STATUS    RESTARTS   AGE   IP            NODE         NOMINATED NODE   READINESS GATES
kube-flannel-ds-amd64-888nz   1/1     Running   0          14m   10.16.8.153   k8s-node02   <none>           <none>
kube-flannel-ds-amd64-bnfwj   1/1     Running   0          14m   10.16.8.152   k8s-node01   <none>           <none>
kube-flannel-ds-amd64-hvgzc   1/1     Running   0          14m   10.16.8.154   k8s-node03   <none>           <none>

查看node的状态已经是ready：

[root@k8s-master01 yaml]# kubectl get node
NAME         STATUS   ROLES    AGE     VERSION
k8s-node01   Ready    <none>   4h      v1.16.0
k8s-node02   Ready    <none>   3h57m   v1.16.0
k8s-node03   Ready    <none>   3h57m   v1.16.0