K8S环境安装第三篇：安装dashbord的那些坑

之前写过两篇这个K8S安装的，但是还没写怎么安装dashbord可视化页面的。因为最近虚拟机出了问题，导致又要重新安装一遍。这里就借此完善下。

接下来我们在在master节点上部署k8s-dashboard组件，该组件为k8s的web ui组件：

1. 执行下面文件内容 kubernetes-dashboard.yaml

kubectl apply -f kubernetes-dashboard.yaml

文件内容如下：标记红色的地方是特别需要留意的地方，避免不必要的问题

# Copyright 2017 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# ------------------- Dashboard Secret ------------------- #

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kube-system
type: Opaque

---
# ------------------- Dashboard Service Account ------------------- #

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system

---
# ------------------- Dashboard Role & Role Binding ------------------- #

kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
rules:
  # Allow Dashboard to create 'kubernetes-dashboard-key-holder' secret.
- apiGroups: [""]
  resources: ["secrets"]
  verbs: ["create"]
  # Allow Dashboard to create 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
  resources: ["configmaps"]
  verbs: ["create"]
  # Allow Dashboard to get, update and delete Dashboard exclusive secrets.
- apiGroups: [""]
  resources: ["secrets"]
  resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs"]
  verbs: ["get", "update", "delete"]
  # Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
  resources: ["configmaps"]
  resourceNames: ["kubernetes-dashboard-settings"]
  verbs: ["get", "update"]
  # Allow Dashboard to get metrics from heapster.
- apiGroups: [""]
  resources: ["services"]
  resourceNames: ["heapster"]
  verbs: ["proxy"]
- apiGroups: [""]
  resources: ["services/proxy"]
  resourceNames: ["heapster", "http:heapster:", "https:heapster:"]
  verbs: ["get"]

---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: kubernetes-dashboard-minimal
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system

---
# ------------------- Dashboard Deployment ------------------- #

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
      - name: kubernetes-dashboard
        image: registry.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.10.1
        ports:
        - containerPort: 8443
          protocol: TCP
        args:
          - --auto-generate-certificates
          # Uncomment the following line to manually specify Kubernetes API server Host
          # If not specified, Dashboard will attempt to auto discover the API server and connect
          # to it. Uncomment only if the default does not work.
          # - --apiserver-host=http://my-address:port
        volumeMounts:
        - name: kubernetes-dashboard-certs
          mountPath: /certs
          # Create on-disk volume to store exec logs
        - mountPath: /tmp
          name: tmp-volume
        livenessProbe:
          httpGet:
            scheme: HTTPS
            path: /
            port: 8443
          initialDelaySeconds: 30
          timeoutSeconds: 30
      volumes:
      - name: kubernetes-dashboard-certs
        secret:
          secretName: kubernetes-dashboard-certs
      - name: tmp-volume
        emptyDir: {}
      serviceAccountName: kubernetes-dashboard
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule

---
# ------------------- Dashboard Service ------------------- #

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
    - port: 443
      targetPort: 8443
      nodePort:30001
  selector:
    k8s-app: kubernetes-dashboard

2. 查看访问dashboard服务的端口号，访问IP使用master节点的IP地址

 [root@k8s-node1 dashboard-certs]# kubectl get svc kubernetes-dashboard -n kube-system

 访问连接：

https://192.168.56.100:30001/

3. 如何使用令牌登陆：

[root@k8s-node1]# kubectl create serviceaccount dashboard-admin -n kube-system
[root@k8s-node1]# kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin

[root@k8s-node1 dashboard-certs]# kubectl  get secret -n kube-system|grep dashboard

[root@k8s-node1 dashboard-certs]# kubectl describe secret dashboard-admin-token-7v2gn -n kube-system

最后登录的效果如下：

 4. 其他可能问题

K8s集群排错，断电重启The connection to the server apiserver.k8s:6443 was refused - did you specify the right

解决方案
1.首先确保Swap 已经关闭
可以采用临时关闭 swapoff -a 但是断电重启之后需要再次设置 也可以设置永久关闭
2各个节点之间防火墙 一定要检查   systemctl stop firewalld

3.查看kubelet 服务 是否正常  systemctl status kubelet

4.如果一会又不正常了请看详细信息  journalctl -xefu kubelet

5.如果发现Unit kubelet.service entered failed state.code=exited, status=255 说明这台节点有污点 ，将污点删除。

rm -rf /var/lib/kubelet/cpu_manager_state
6.排除问题之后 systemctl start kubelet 重启完成
7.查看node ,pod

kubectl get node
kubectl get pods --all-namespaces

kubernetes dashboard 的权限错误

执行如下命令即可：
kubectl create clusterrolebinding kubernetes-dashboard --clusterrole=cluster-admin --serviceaccount=kube-system:kubernetes-dashboard

以上为主要内容。记录一下，以后重新安装不费劲。