kubernetes-handbook/practice/dashboard-addon-installatio...

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# 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](dashboard-upgrade.md)。
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:
``` bash
$ ls *.yaml
dashboard-controller.yaml dashboard-service.yaml dashboard-rbac.yaml
```
已经修改好的 yaml 文件见:[../manifests/dashboard](https://github.com/rootsongjc/kubernetes-handbook/blob/master/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:
```yaml
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
``` bash
$ 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
``` bash
$ 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
``` bash
$ 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
``` bash
$ 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
``` bash
$ 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 dashboardhttps 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
``` bash
$ 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 URLhttp://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
``` bash
$ 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](https://github.com/opsnull/follow-me-install-kubernetes-cluster/issues/5),已经解决。
**导入证书**
将生成的admin.pem证书转换格式
```bash
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](../images/kubernetes-dashboard-raw.jpg)
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`
```yaml
image: harbor-001.jimmysong.io/library/kubernetes-dashboard-amd64:v1.6.3
```
然后执行下面的命令:
```bash
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:
```bash
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](../images/dashboard-v163.jpg)
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](dashboard-upgrade.md)。
## 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](../images/dashboard-addon-installation001.png)
可以尝试删除所有相关“资源”再重试一次secret、serviceaccount、service、pod、deployment
场景二:
```bash
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](https://kubernetes.io/docs/reference/access-authn-authz/rbac/#service-account-permissions)。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
```bash
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"
```
## 参考
- [WebUI(Dashboard) 文档](https://kubernetes.io/docs/tasks/access-application-cluster/web-ui-dashboard/)