安装dashboard插件

注意:本文档中安装的是kubernetes dashboard v1.6.0,安装新版的dashboard请参考升级dashboard

官方文件目录:https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/dashboard

我们使用的文件如下:

$ ls *.yaml
dashboard-controller.yaml  dashboard-service.yaml dashboard-rbac.yaml

已经修改好的 yaml 文件见:../manifests/dashboard

文件中的kubernetes-dashboard-amd64镜像为本地镜像地址需要修改为对应的镜像地址和版本:

kubernetes 1.7.11 可以使用此镜像地址:registry.cn-qingdao.aliyuncs.com/haitao/kubernetes-dashboard-amd64:v1.7.0 替换 dashboard-controller.yaml 文件中的镜像地址。

由于 kube-apiserver 启用了 RBAC 授权,而官方源码目录的 dashboard-controller.yaml 没有定义授权的 ServiceAccount,所以后续访问 API server 的 API 时会被拒绝,web中提示:

Forbidden (403)

User "system:serviceaccount:kube-system:default" cannot list jobs.batch in the namespace "default". (get jobs.batch)

增加了一个dashboard-rbac.yaml文件,定义一个名为 dashboard 的 ServiceAccount,然后将它和 Cluster Role view 绑定,如下:

apiVersion: v1
kind: ServiceAccount
metadata:
  name: dashboard
  namespace: kube-system
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: dashboard
subjects:
  - kind: ServiceAccount
    name: dashboard
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io

然后使用kubectl apply -f dashboard-rbac.yaml创建。

配置dashboard-service

$ diff dashboard-service.yaml.orig dashboard-service.yaml
10a11
>   type: NodePort
  • 指定端口类型为 NodePort,这样外界可以通过地址 nodeIP:nodePort 访问 dashboard;

配置dashboard-controller

$ diff dashboard-controller.yaml.orig dashboard-controller.yaml
23c23
<         image: gcr.io/google_containers/kubernetes-dashboard-amd64:v1.6.0
---
>         image: harbor-001.jimmysong.io/library/kubernetes-dashboard-amd64:v1.6.0

执行所有定义文件

$ pwd
/root/kubernetes/cluster/addons/dashboard
$ ls *.yaml
dashboard-controller.yaml  dashboard-service.yaml
$ kubectl create -f  .
service "kubernetes-dashboard" created
deployment "kubernetes-dashboard" created

检查执行结果

查看分配的 NodePort

$ kubectl get services kubernetes-dashboard -n kube-system
NAME                   CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes-dashboard   10.254.224.130   <nodes>       80:30312/TCP   25s
  • NodePort 30312映射到 dashboard pod 80端口;

检查 controller

$ kubectl get deployment kubernetes-dashboard  -n kube-system
NAME                   DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kubernetes-dashboard   1         1         1            1           3m
$ kubectl get pods  -n kube-system | grep dashboard
kubernetes-dashboard-1339745653-pmn6z   1/1       Running   0          4m

访问dashboard

有以下三种方式:

  • kubernetes-dashboard 服务暴露了 NodePort,可以使用 http://NodeIP:nodePort 地址访问 dashboard
  • 通过 API server 访问 dashboard(https 6443端口和http 8080端口方式)
  • 通过 kubectl proxy 访问 dashboard

通过 kubectl proxy 访问 dashboard

启动代理

$ kubectl proxy --address='172.20.0.113' --port=8086 --accept-hosts='^*$'
Starting to serve on 172.20.0.113:8086
  • 需要指定 --accept-hosts 选项,否则浏览器访问 dashboard 页面时提示 “Unauthorized”;

浏览器访问 URL:http://172.20.0.113:8086/ui
自动跳转到:http://172.20.0.113:8086/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard/#/workload?namespace=default

通过 API server 访问dashboard

获取集群服务地址列表

$ kubectl cluster-info
Kubernetes master is running at https://172.20.0.113:6443
KubeDNS is running at https://172.20.0.113:6443/api/v1/proxy/namespaces/kube-system/services/kube-dns
kubernetes-dashboard is running at https://172.20.0.113:6443/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard

浏览器访问 URL:https://172.20.0.113:6443/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard(浏览器会提示证书验证,因为通过加密通道,以改方式访问的话,需要提前导入证书到你的计算机中)。这是我当时在这遇到的坑:通过 kube-apiserver 访问dashboard,提示User “system:anonymous” cannot proxy services in the namespace “kube-system”. #5,已经解决。

导入证书

将生成的admin.pem证书转换格式

openssl pkcs12 -export -in admin.pem  -out admin.p12 -inkey admin-key.pem

将生成的admin.p12证书导入的你的电脑,导出的时候记住你设置的密码,导入的时候还要用到。

如果你不想使用https的话,可以直接访问insecure port 8080端口:http://172.20.0.113:8080/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard

kubernetes dashboard

由于缺少 Heapster 插件,当前 dashboard 不能展示 Pod、Nodes 的 CPU、内存等 metric 图形。

更新

Kubernetes 1.6 版本的 dashboard 的镜像已经到了 v1.6.3 版本,我们可以使用下面的方式更新。

修改 dashboard-controller.yaml 文件中的镜像的版本将 v1.6.0 更改为 v1.6.3

image: harbor-001.jimmysong.io/library/kubernetes-dashboard-amd64:v1.6.3

然后执行下面的命令:

kubectl apply -f dashboard-controller.yaml

即可在线更新 dashboard 的版本。

监听 dashboard Pod 的状态可以看到:

kubernetes-dashboard-215087767-2jsgd   0/1       Pending   0         0s
kubernetes-dashboard-3966630548-0jj1j   1/1       Terminating   0         1d
kubernetes-dashboard-215087767-2jsgd   0/1       Pending   0         0s
kubernetes-dashboard-3966630548-0jj1j   1/1       Terminating   0         1d
kubernetes-dashboard-215087767-2jsgd   0/1       ContainerCreating   0         0s
kubernetes-dashboard-3966630548-0jj1j   0/1       Terminating   0         1d
kubernetes-dashboard-3966630548-0jj1j   0/1       Terminating   0         1d
kubernetes-dashboard-215087767-2jsgd   1/1       Running   0         6s
kubernetes-dashboard-3966630548-0jj1j   0/1       Terminating   0         1d
kubernetes-dashboard-3966630548-0jj1j   0/1       Terminating   0         1d
kubernetes-dashboard-3966630548-0jj1j   0/1       Terminating   0         1d

新的 Pod 的启动了,旧的 Pod 被终结了。

Dashboard 的访问地址不变,重新访问 http://172.20.0.113:8080/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard,可以看到新版的界面:

V1.6.3版本的dashboard界面

新版本中最大的变化是增加了进入容器内部的入口,可以在页面上进入到容器内部操作,同时又增加了一个搜索框。

关于如何将dashboard从1.6版本升级到1.7版本请参考升级dashboard

问题

1. 按照教程安装后,发现dashboard pod 无法启动

场景一

kubectl -n kube-system describe pod dashboard-xxxxxxx

pod无法正常启动

可以尝试删除所有相关“资源”再重试一次,如:secret、serviceaccount、service、pod、deployment

场景二

   kubectl describe pod -n kube-system kubernetes-dashboard-7b7bf9bcbd-xxxxx
   Events:
   Type     Reason                 Age                From                    Message
   ----     ------                 ----               ----                    -------
   Normal   Scheduled              49s                default-scheduler       Successfully assigned kubernetes-dashboard-7b7bf9bcbd-625cb to 192.168.1.101
   Normal   SuccessfulMountVolume  49s                kubelet, 192.168.1.101  MountVolume.SetUp succeeded for volume "tmp-volume"
   Warning  FailedMount            17s (x7 over 49s)  kubelet, 192.168.1.101  MountVolume.SetUp failed for volume "kubernetes-dashboard-certs" : secrets "kubernetes-dashboard-certs" is forbidden: User "system:node:192.168.1.233" cannot get secrets in the namespace "kube-system": no path found to object
   Warning  FailedMount            17s (x7 over 49s)  kubelet, 192.168.1.101  MountVolume.SetUp failed for volume "kubernetes-dashboard-token-27kdp" : secrets "kubernetes-dashboard-token-27kdp" is forbidden: User "system:node:192.168.1.233" cannot get secrets in the namespace "kube-system": no path found to object

通过官方文档:RBAC。可以了解到,对于k8s1.8+版本,system:node不会进行默认绑定。因此对于分配到其他node的pod,会出现forbidden。

需要手动bind各个node:

   kubectl create clusterrolebinding node233 --clusterrole=system:node --user=system:node:192.168.1.233
   kubectl describe pod -n kube-system kubernetes-dashboard-7b7bf9bcbd-xxxxx
   Events:
   Type    Reason                 Age   From                    Message
   ----    ------                 ----  ----                    -------
   Normal  Scheduled              15s   default-scheduler       Successfully assigned kubernetes-dashboard-7b7bf9bcbd-pq6pk to 192.168.1.101
   Normal  SuccessfulMountVolume  15s   kubelet, 192.168.1.101  MountVolume.SetUp succeeded for volume "tmp-volume"
   Normal  SuccessfulMountVolume  15s   kubelet, 192.168.1.101  MountVolume.SetUp succeeded for volume "kubernetes-dashboard-certs"
   Normal  SuccessfulMountVolume  15s   kubelet, 192.168.1.101  MountVolume.SetUp succeeded for volume "kubernetes-dashboard-token-8rj79"
   Normal  Pulling                15s   kubelet, 192.168.1.101  pulling image "registry.cn-hangzhou.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.8.3"

2. 自定义dashboard启动参数

可以在dashboard的YAML文件中配置启动参数,比如设置token的默认过期时间、heapster地址、绑定的证书等。

参考