Kubernetes web界面kubernetes-dashboard安装

本文讲述的是如何部署K8s的web UI，前提是已经有一个k8s集群后，按照如下步骤进行即可。(如下步骤都是在master节点上进行操作)

1、下载kubernetes-dashboard.yaml文件

wget https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml

2、修改kubernetes-dashboard.yaml文件

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

kind: Deployment
apiVersion: apps/v1beta2
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  replicas:
  revisionHistoryLimit:
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
      - name: kubernetes-dashboard
        image: registry.cn-hangzhou.aliyuncs.com/kube_containers/kubernetes-dashboard-amd64
        ports:
        - containerPort:
          protocol: TCP
        args:
          - --auto-generate-certificates

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

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

上面代码红色字为kubernetes-dashboard.yaml文件中需要修改的地方，不然拉取不了镜像，以及使用Nodeport方式做映射，使其他主机能够访问该dashboard。

3、创建kubernetes-dashboard.yaml

kubectl create -f kubernetes-dashboard.yaml

4、查看kubernetes-dashboard容器是否已经运行

[root@docker-master1 ~]# kubectl get pods -n kube-system
NAME                                     READY   STATUS    RESTARTS   AGE
coredns-576cbf47c7-l5wlh                 /     Running             3d8h
coredns-576cbf47c7-zrl66                 /     Running             3d8h
etcd-docker-master1                      /     Running             3d8h
kube-apiserver-docker-master1            /     Running             3d8h
kube-controller-manager-docker-master1   /     Running             3d8h
kube-flannel-ds-amd64-c7wz6              /     Running             3d8h
kube-flannel-ds-amd64-hqvz9              /     Running             3d8h
kube-flannel-ds-amd64-w7n4s              /     Running             3d8h
kube-proxy-8gj2w                         /     Running             3d8h
kube-proxy-mt6dk                         /     Running             3d8h
kube-proxy-qtxz7                         /     Running             3d8h
kube-scheduler-docker-master1            /     Running             3d8h
kubernetes-dashboard-5f864b6c5f-5s2rw    1/1     Running   0          62m

如上红色字体已经显示kubernetes-dashboard已经成功在node节点上运行。当然，你也可以前往node节点上执行docker ps查看kubernetes-dashboard容器是否已经启动，netstat -ptln命令查看30001端口是否已经开放。

5、创建kubernetes-dashboard管理员角色

[root@docker-master1 ~]# vi k8s-admin.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: dashboard-admin
  namespace: kube-system
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: dashboard-admin
subjects:
  - kind: ServiceAccount
    name: dashboard-admin
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io

6、加载管理员角色

kubectl create -f k8s-admin.yaml

7、获取dashboard管理员角色token

#获取dashboard secret
kubectl get secret -n kube-system
[root@docker-master1 ~]# kubectl get secret -n kube-system
NAME                                             TYPE                                  DATA   AGE
attachdetach-controller-token-d9w8c              kubernetes.io/service-account-token         3d8h
bootstrap-signer-token-jdjwt                     kubernetes.io/service-account-token         3d8h
bootstrap-token-9n6rpz                           bootstrap.kubernetes.io/token               149m
bootstrap-token-n962df                           bootstrap.kubernetes.io/token               3d8h
certificate-controller-token-lktt8               kubernetes.io/service-account-token         3d8h
clusterrole-aggregation-controller-token-7stf6   kubernetes.io/service-account-token         3d8h
coredns-token-kbz5z                              kubernetes.io/service-account-token         3d8h
cronjob-controller-token-b647q                   kubernetes.io/service-account-token         3d8h
daemon-set-controller-token-tzlpk                kubernetes.io/service-account-token         3d8h
dashboard-admin-token-jc8t5                      kubernetes.io/service-account-token   3      17m

#获取token
[root@docker-master1 ~]# kubectl describe secret dashboard-admin-token-jc8t5 -n kube-system
Name:         dashboard-admin-token-jc8t5
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: dashboard-admin
              kubernetes.io/service-account.uid: cdfb442a-f48b-11e8-80e8-000c29c3dca5

Type:  kubernetes.io/service-account-token

Data
====
namespace:   bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.FZCsonMyEdcDDvbzIz7rMxm8vvlk0Ck6O5ooqzaJRWkggwMoqf92qYBsNxMxxT5BdAtxB_iPUD7rEagR7sLTqixHeC0HdTnGCcTnNU1fq2KJA5ssNyi9P4XGJqsGuf4mAmF5L56uBh43X4hQ41rFYPQwIrmVnknTAbAWf3biiKWkN9Az8NsCulRSSCsJSOwfPoGlo7aSbMYTyRXlmzLuLbkMpMvyMHChBJ_MIYbH9dBj_hL3L9iwo9gpNTfB-0_uYHPEPdQcib8qUkC5NxgXdBuQPug5y1kLUVFNgq45ozLTibZuVihK_gza-WKVpBRPY5PaYCN1Gu0-tFObUYDUow

8、使用管理员角色登陆kubernetes-dashboard web界面

客户端浏览器输入：https://nodeIP:nodeport ，也就是kubernetes-dashboard容器在哪台node节点上跑，以及上面设置的nodeport端口（我这里是https://192.168.20.214:30001）

出现如下界面，选择令牌——输入令牌，（令牌为上面的token）

9、dashboard访问方式

根据官方文档，目前访问Dashboard有四种方式：

• NodePort
• API Server
• kubectl proxy
• Ingress

以上四种方式，我测试了前三种，目前只有NodePort和kubectl proxy可用，API Server暂时没有解决。

1. 使用NodePort

　　 为kubernetes-dashboard.yaml添加Service后，就可以使用NodePort访问Dashboard。在我们的物理机上，使用Chrome访问https://192.168.20.214:30001/，如上2步骤。（2步骤使用的就是nodeport方式访问）

如访问提示了证书错误NET::ERR_CERT_INVALID，原因是由于物理机的浏览器证书不可用。我们可以生成一个私有证书或者使用公有证书，下面开始配置证书。

#1、查看kubernetes-dashboard 容器跑在哪台node节点上，这里跑在docker-slave2上
root@docker-master1 pki]# kubectl get pod -n kube-system -o wide
NAME                                     READY   STATUS    RESTARTS   AGE     IP               NODE             NOMINATED NODE
coredns-576cbf47c7-l5wlh                 /     Running             9d      10.244.0.5       docker-master1   <none>
coredns-576cbf47c7-zrl66                 /     Running             9d      10.244.0.4       docker-master1   <none>
etcd-docker-master1                      /     Running             9d      192.168.20.210   docker-master1   <none>
kube-apiserver-docker-master1            /     Running             9d      192.168.20.210   docker-master1   <none>
kube-controller-manager-docker-master1   /     Running             9d      192.168.20.210   docker-master1   <none>
kube-flannel-ds-amd64-c7wz6              /     Running             9d      192.168.20.213   docker-slave1    <none>
kube-flannel-ds-amd64-hqvz9              /     Running             9d      192.168.20.214   docker-slave2    <none>
kube-flannel-ds-amd64-w7n4s              /     Running             9d      192.168.20.210   docker-master1   <none>
kube-proxy-8gj2w                         /     Running             9d      192.168.20.210   docker-master1   <none>
kube-proxy-mt6dk                         /     Running             9d      192.168.20.213   docker-slave1    <none>
kube-proxy-qtxz7                         /     Running             9d      192.168.20.214   docker-slave2    <none>
kube-scheduler-docker-master1            /     Running             9d      192.168.20.210   docker-master1   <none>
kubernetes-dashboard-5f864b6c5f-5s2rw    1/1     Running   0          5d21h   10.244.3.9       docker-slave2    <none>

#2、在docker-slave2节点上查看kubernetes-dashboard容器ID
root@docker-slave2 ~]# docker ps | grep dashboard
384d9dc0170b        registry.cn-hangzhou.aliyuncs.com/kube_containers/kubernetes-dashboard-amd64   "/dashboard --insecu…"    days ago          Up  hours                             k8s_kubernetes-dashboard_kubernetes-dashboard-5f864b6c5f-5s2rw_kube-system_94c8c50b-f484-11e8-80e8-000c29c3dca5_0

#3、查看kubernetes-dashboard容器certs所挂载的宿主主机目录
[root@docker-slave2 ~]# docker inspect -f {{.Mounts}} 384d9dc0170b
"Mounts": [
            {
                "Type": "bind",
                "Source": "/var/lib/kubelet/pods/94c8c50b-f484-11e8-80e8-000c29c3dca5/volumes/kubernetes.io~empty-dir/tmp-volume",
                "Destination": "/tmp",
                "Mode": "",
                "RW": true,
                "Propagation": "rprivate"
            },
            {
                "Type": "bind",
                "Source": "/var/lib/kubelet/pods/94c8c50b-f484-11e8-80e8-000c29c3dca5/volumes/kubernetes.io~secret/kubernetes-dashboard-token-tbctd",
                "Destination": "/var/run/secrets/kubernetes.io/serviceaccount",
                "Mode": "ro",
                "RW": false,
                "Propagation": "rprivate"
            },
            {
                "Type": "bind",
                "Source": "/var/lib/kubelet/pods/94c8c50b-f484-11e8-80e8-000c29c3dca5/etc-hosts",
                "Destination": "/etc/hosts",
                "Mode": "",
                "RW": true,
                "Propagation": "rprivate"
            },
            {
                "Type": "bind",
                "Source": "/var/lib/kubelet/pods/94c8c50b-f484-11e8-80e8-000c29c3dca5/containers/kubernetes-dashboard/0e84c511",
                "Destination": "/dev/termination-log",
                "Mode": "",
                "RW": true,
                "Propagation": "rprivate"
            },
            {
                "Type": "bind",
                "Source": "/var/lib/kubelet/pods/94c8c50b-f484-11e8-80e8-000c29c3dca5/volumes/kubernetes.io~secret/kubernetes-dashboard-certs",
                "Destination": "/certs",
                "Mode": "ro",
                "RW": false,
                "Propagation": "rprivate"
            }
        ],

#4、这里以私有证书配置，生成dashboard证书
openssl genrsa -des3 -passout pass:x -out dashboard.pass.key
openssl rsa -passin pass:x -in dashboard.pass.key -out dashboard.key
openssl req -new -key dashboard.key -out dashboard.csr
openssl x509 -req -sha256 -days  -in dashboard.csr -signkey dashboard.key -out dashboard.crt

#、将生成的dashboard.crt  dashboard.key放到certs对应的宿主主机souce目录
scp dashboard.crt dashboard.key 192.168.20.214:/var/lib/kubelet/pods/94c8c50b-f484-11e8-80e8-000c29c3dca5/volumes/kubernetes.io~secret/kubernetes-dashboard-certs

#、重启kubernetes-dashboard容器
docker restart 384d9dc0170b

完成以上步骤即可访问kubernetes-dashboard web了，由于使用的是私有证书，所以还是会弹出不安全的连接，需要添加例外。

2、使用API Server

在我们的物理机上，使用Chrome访问地址：https://192.168.20.210:6443/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/，返回如下错误：

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

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

原因是由于kube-apiserver使用了TLS认证，而我们的真实物理机上的浏览器使用匿名证书（因为没有可用的证书）去访问Dashboard，导致授权失败而不无法访问。官方提供的解决方法是将kubelet的证书转化为浏览器可用的证书，然后导入进浏览器。但是该方法目前似乎不适用于kubeadm方式安装的集群，参见：https://github.com/opsnull/follow-me-install-kubernetes-cluster/issues/5 。看来，无论物理机还是K8S节点上的浏览器，都需要导入这个证书，暂时无解。

3、使用kubectl proxy

这里，我主要介绍一下最便捷的kubectl proxy方式。在Master上执行nohup kubecll proxy &，然后使用如下地址访问Dashboard：

http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy

但限制就是必须在Master上访问，这显然是个坑，我们的目标是在我们真实的物理机上去访问Master的Dashboard。

所以，在主节点上，我们执行nohup kubectl proxy --address=192.168.20.210 --disable-filter=true & 开启代理。

其中：

• address表示外界可以使用192.168.20.210来访问Dashboard，我们也可以使用0.0.0.0
• disable-filter=true表示禁用请求过滤功能，否则我们的请求会被拒绝，并提示 Forbidden (403) Unauthorized。
• 我们也可以指定端口，具体请查看kubectl proxy --help

此时proxy默认对Master的8001端口进行监听：

这样，我们就可以使用如下地址访问登录界面：

http://192.168.20.210:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/login