k8s kubeadm安装

1. 检查是否已经安装kubectl, kubelet, kubeadm，直接输入命令确定

2. 如果安装，使用apt remove和snap remove删除

3. 确保均删除干净

4. 确保docker已经安装

5. 参考https://zhuanlan.zhihu.com/p/654320979

6. kubeadm版本不应该超过1.25.0，因为1.25.0之后k8s使用了containerd。

7. 出错后首先：kubeadm reset

8. 然后检查日志

9. init成功后，检查kubectl

    $ kubectl get pod -A
   

   此时仍有两个没有打开

10. 需要配置网络

创建文件flannel.yaml，内容如下，

---
kind: Namespace
apiVersion: v1
metadata:
  name: kube-flannel
  labels:
    k8s-app: flannel
    pod-security.kubernetes.io/enforce: privileged
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
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
- apiGroups:
  - networking.k8s.io
  resources:
  - clustercidrs
  verbs:
  - list
  - watch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
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
kind: ServiceAccount
metadata:
  labels:
    k8s-app: flannel
  name: flannel
  namespace: kube-flannel
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-flannel
  labels:
    tier: node
    k8s-app: flannel
    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": "vxlan"
      }
    }
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds
  namespace: kube-flannel
  labels:
    tier: node
    app: flannel
    k8s-app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/os
                operator: In
                values:
                - linux
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni-plugin
        image: rancher/mirrored-flannelcni-flannel-cni-plugin:v1.0.0
       #image: docker.io/rancher/mirrored-flannelcni-flannel-cni-plugin:v1.1.2
        command:
        - cp
        args:
        - -f
        - /flannel
        - /opt/cni/bin/flannel
        volumeMounts:
        - name: cni-plugin
          mountPath: /opt/cni/bin
      - name: install-cni
        image: lizhenliang/flannel:v0.11.0-amd64
       #image: docker.io/rancher/mirrored-flannelcni-flannel:v0.21.5
        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
       #image: docker.io/rancher/mirrored-flannelcni-flannel:v0.21.5
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
            add: ["NET_ADMIN", "NET_RAW"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        - name: EVENT_QUEUE_DEPTH
          value: "5000"
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
        - name: xtables-lock
          mountPath: /run/xtables.lock
      volumes:
      - name: run
        hostPath:
          path: /run/flannel
      - name: cni-plugin
        hostPath:
          path: /opt/cni/bin
      - name: cni
        hostPath:
          path: /etc/cni/net.d
      - name: flannel-cfg
        configMap:
          name: kube-flannel-cfg
      - name: xtables-lock
        hostPath:
          path: /run/xtables.lock
          type: FileOrCreate

创建完成后执行kubectl apply -f flannel.yaml，执行很快，但是需要等待一会才会启动，一会会出现

wzh@chen:~$ kubectl get pod -A
NAMESPACE      NAME                           READY   STATUS    RESTARTS   AGE
kube-flannel   kube-flannel-ds-xqpqb          1/1     Running   0          11h
kube-system    coredns-7f6cbbb7b8-w5lp8       1/1     Running   0          12h
kube-system    coredns-7f6cbbb7b8-xmps6       1/1     Running   0          12h
kube-system    etcd-chen                      1/1     Running   0          12h
kube-system    kube-apiserver-chen            1/1     Running   0          12h
kube-system    kube-controller-manager-chen   1/1     Running   0          12h
kube-system    kube-proxy-c5tks               1/1     Running   0          12h
kube-system    kube-scheduler-chen            1/1     Running   0          12h
wzh@chen:~$ kubectl get nodes
NAME   STATUS   ROLES                  AGE   VERSION
chen   Ready    control-plane,master   13h   v1.22.7