Kubernetes dashboard1.8.0 WebUI安装与配置

kubernetes-dashboard.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
    addonmanager.kubernetes.io/mode: Reconcile
  name: kubernetes-dashboard
  namespace: kube-system
---
apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: kubernetes-dashboard
  namespace: kube-system
  labels:
    k8s-app: kubernetes-dashboard
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
spec:
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ''
    spec:
      serviceAccountName: kubernetes-dashboard
      containers:
      - name: kubernetes-dashboard
        image: 10.0.11.222:5000/bigdata/kubernetes-dashboard-amd64:v1.8.0
        resources:
          limits:
            cpu: 100m
            memory: 300Mi
          requests:
            cpu: 100m
            memory: 100Mi
        ports:
        - containerPort: 8443
          protocol: TCP
        args:
          - --auto-generate-certificates
        volumeMounts:
        - name: kubernetes-dashboard-certs
          mountPath: /certs
        - name: tmp-volume
          mountPath: /tmp
        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
      tolerations:
      - key: "CriticalAddonsOnly"
        operator: "Exists"
---
apiVersion: v1
kind: Service
metadata:
  name: kubernetes-dashboard
  namespace: kube-system
  labels:
    k8s-app: kubernetes-dashboard
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
spec:
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard
  ports:
  - port: 443
    targetPort: 8443

spec.containers.image：填写dashboard的镜像路径。我这里填写的是本地私有库的dashboard镜像。大家可以通过docker search查询1.8.0版本的dashboard。

spec.containers.args：此处填写的是一些参数，由于我的kubernetes1.8.0是通过HTTPS安全验证的安装，访问的是http://masterip:6443，因此，此处我填写了- --auto-generate-certificates，用以自动生成dashboard证书，此处不需要填写apiserver地址。

kubernetes-rbac.yaml

因为kubernetes1.8.0开启了 RBAC 所以这里需要创建一个 RBAC 认证。

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

---

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: kubernetes-dashboard
subjects:
  - kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io

dashboard安装启动

kubernetes-dashboard-certs创建

新建一个空目录：certs，然后执行下面命令：

kubectl create secret generic kubernetes-dashboard-certs --from-file=certs -n kube-system

将上面两个文件kubernetes-dashboard.yaml、kubernetes-rbac.yaml放置到同一个目录，该目录只要这两个文件，然后执行下面的命令：

安装启动

# 读取当前目录配置文件进行安装启动
kubectl apply -f .

查看pod

查看namespace为kube-system下的pod

kubectl get pods --namespace="kube-system"


NAME                                   READY     STATUS    RESTARTS   AGE
kubernetes-dashboard-77bd6c79b-sc5wb   1/1       Running   1          56m

查看指定pod详情

pods/后面跟指定pod name

kubectl describe pods/kubernetes-dashboard-77bd6c79b-sc5wb --namespace="kube-system" 

由于详情过多，此处截图只展示部分信息：

查看dashboard界面

访问以下链接（1.8.0访问 https://masterip:6443/ui 无法访问）：

https://MasterIP:6443/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/

MasterIP：kubernetes集群master节点ip

kubernetes-dashboard界面：

出现的问题

首次安装，如果没有做apiserver参数配置，则可能会出现一些问题。下面就看下常见问题的解决方法

system:anonymous问题

访问dashboard网页时，可能出现下面这种报错：

{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {

  },
  "status": "Failure",
  "message": "services \"https:kubernetes-dashboard:\" is forbidden: User \"system:anonymous\" cannot get services/proxy in the namespace \"kube-system\"",
  "reason": "Forbidden",
  "details": {
    "name": "https:kubernetes-dashboard:",
    "kind": "services"
  },
  "code": 403
}

Kubernetes API Server新增了–anonymous-auth选项，允许匿名请求访问secure port。没有被其他authentication方法拒绝的请求即Anonymous requests， 这样的匿名请求的username为system:anonymous, 归属的组为system:unauthenticated。并且该选线是默认的。这样一来，当采用chrome浏览器访问dashboard UI时很可能无法弹出用户名、密码输入对话框，导致后续authorization失败。为了保证用户名、密码输入对话框的弹出，需要将–anonymous-auth设置为false。

解决方法：

在api-server配置文件中添加--anonymous-auth=false

vi /etc/systemd/system/kube-apiserver.service

[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target

[Service]
User=root
ExecStart=/usr/local/bin/kube-apiserver \
  --admission-control=NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota,NodeRestriction \
  --advertise-address=10.0.11.222 \
  --allow-privileged=true \
  --apiserver-count=3 \
  --audit-policy-file=/etc/kubernetes/audit-policy.yaml \
  --audit-log-maxage=30 \
  --audit-log-maxbackup=3 \
  --audit-log-maxsize=100 \
  --audit-log-path=/var/log/kubernetes/audit.log \
  --authorization-mode=Node,RBAC \
  --anonymous-auth=false \ # 不接受匿名访问，若为true，则表示接受，此处设置为false，便于dashboard访问
  --bind-address=0.0.0.0 \
  --secure-port=6443 \
  --client-ca-file=/etc/kubernetes/ssl/ca.pem \
  --enable-swagger-ui=true \
  --etcd-cafile=/etc/kubernetes/ssl/ca.pem \
  --etcd-certfile=/etc/kubernetes/ssl/etcd.pem \
  --etcd-keyfile=/etc/kubernetes/ssl/etcd-key.pem \
  --etcd-servers=https://10.0.11.222:2379 \
  --event-ttl=1h \
  --kubelet-https=true \
  --insecure-bind-address=127.0.0.1 \
  --insecure-port=8080 \
  --service-account-key-file=/etc/kubernetes/ssl/ca-key.pem \
  --service-cluster-ip-range=10.254.0.0/16 \
  --service-node-port-range=30000-32000 \
  --tls-cert-file=/etc/kubernetes/ssl/kubernetes.pem \
  --tls-private-key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
  --enable-bootstrap-token-auth \
  --token-auth-file=/etc/kubernetes/token.csv \
  --v=2
Restart=on-failure
RestartSec=5
Type=notify
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

Unauthorized问题

解决了上面那个问题之后，再度访问dashboard页面，发现还是有问题，出现下面这个问题：

{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {

  },
  "status": "Failure",
  "message": "Unauthorized",
  "reason": "Unauthorized",
  "code": 401
}

解决方法：
新建/etc/kubernetes/basic_auth_file文件，并在其中添加：

admin,admin,1002

文件内容格式：password,username,uid

然后在api-server配置文件（即上面的配置文件）中添加--basic-auth-file=/etc/kubernetes/basic_auth_file \

保存重启kube-apiserver：

systemctl daemon-reload
systemctl enable kube-apiserver
systemctl start kube-apiserver
systemctl status kube-apiserver

最后在kubernetes上执行下面这条命令：

kubectl create clusterrolebinding login-dashboard-admin --clusterrole=cluster-admin --user=admin

将访问账号名admin与kubernetes-rbac.yaml文件中指定的cluster-admin关联，获得访问权限。

getsockopt: connection timed out’问题

如果安装的docker版本为1.13及以上，并且网络畅通，flannel、etcd都正常，但还是会出现getsockopt: connection timed out'的错误，则可能是iptables配置问题。具体问题：

Error: 'dial tcp 10.233.50.3:8443: getsockopt: connection timed out

docker从1.13版本开始，可能将iptables FORWARD chain的默认策略设置为DROP，从而导致ping其他Node上的Pod IP失败，遇到这种问题时，需要手动设置策略为ACCEPT：

sudo iptables -P FORWARD ACCEPT

使用iptables -nL命令查看，发现Forward的策略还是drop，可是我们明明执行了iptables -P FORWARD ACCEPT。原来，docker是在这句话执行之后启动的，需要每次在docker之后再执行这句话。。。这么做有点太麻烦了，所以我们修改下docker的启动脚本：

 vi /usr/lib/systemd/system/docker.service


[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker

ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS $DOCKER_OPTS $DOCKER_DNS_OPTIONS

# 添加这行操作，在每次重启docker之前都会设置iptables策略为ACCEPT
ExecStartPost=/sbin/iptables -I FORWARD -s 0.0.0.0/0 -j ACCEPT

ExecReload=/bin/kill -s HUP $MAINPID

在启动文件中的 [Service] 下添加一行配置，即上面代码中的配置即可。

然后重启docker，再次查看dashboard网页。

参考文章：
1. 解决Kubernetes 1.6.4 Dashboard无法访问的问题
2. Kubernetes集群Dashboard插件安装
3. 解决Centos7下Kubernetes(k8s)部署好之后无法访问dashboard