kubernetes之Ingress发布Dashboard(二)

1.什么是Dashboard

Dashboard 是基于网页的 Kubernetes 用户界面。你可以使用 Dashboard 将容器应用部署到 Kubernetes 集群中，也可以对容器应用排错，还能管理集群资源。你可以使用 Dashboard 获取运行在集群中的应用的概览信息，也可以创建或者修改 Kubernetes 资源（如 Deployment，Job，DaemonSet 等等）。例如，你可以对 Deployment 实现弹性伸缩、发起滚动升级、重启 Pod 或者使用向导创建新的应用。

2. 使用Ingress对外发布Dashboard

默认安装完成的dashboard的访问方式是ClusterIP,进而想访问dashboard需更改为nodeport或者loadbalancer或者配置为ingress的方式才能访问dashbaord。本文将以ingress-nginx发布dashboard在外部访问。

2.1 查看dashboard默认的访问方式

我们可以看到默认是clusterip只能在集群内部访问，是无法在集群外部访问的。

# kubectl get pods,svc -n kubernetes-dashboard

NAME                                             READY   STATUS    RESTARTS   AGE

pod/dashboard-metrics-scraper-7c857855d9-chmm9   1/1     Running   0          74m

pod/kubernetes-dashboard-6b79449649-xgdph        1/1     Running   0          74m

NAME                                TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE

service/dashboard-metrics-scraper   ClusterIP   10.96.129.181   <none>        8000/TCP   74m

service/kubernetes-dashboard        ClusterIP   10.96.13.147    <none>        443/TCP    74m

2.2 检查Ingress Controller是否正常。

# kubectl get pods -n ingress-nginx

NAME                             READY   STATUS    RESTARTS        AGE

ingress-nginx-controller-bnmpt   1/1     Running   25 (3d2h ago)   18d

ingress-nginx-controller-cfblk   1/1     Running   26 (3d1h ago)   18d

2.3 创建自签证书，并创建tls类型Secrets

自签发证书。当然生产环境中理应当使用机构签发的证书。

# openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout kube-dashboard.key -out kube-dashboard.crt -subj "/CN=dashboard.kube.com/O=k8s.dashboard.local"

Generating a 2048 bit RSA private key

......+++

.......+++

writing new private key to 'kube-dashboard.key'

-----

创建tls类型的Secret为ingress提供配置。

# kubectl create secret tls dashboard-tls --key kube-dashboard.key --cert kube-dashboard.crt -n kubernetes-dashboard

secret/dashboard-tls created

查看secrets，可以看见类型为tls类型

# kubectl get secret -n kubernetes-dashboard

NAME                               TYPE                                  DATA   AGE

dashboard-tls                      kubernetes.io/tls                     2      15h

default-token-7d7z8                kubernetes.io/service-account-token   3      17h

kubernetes-dashboard-certs         Opaque                                0      17h

kubernetes-dashboard-csrf          Opaque                                1      17h

kubernetes-dashboard-key-holder    Opaque                                2      17h

kubernetes-dashboard-token-c2z56   kubernetes.io/service-account-token   3      17h

2.4 配置Ingress规则。

# cat ingress-dashboard.yaml

apiVersion: networking.k8s.io/v1   类型为v1

kind: Ingress

metadata:

  name: dashboard-ingress

  namespace: kubernetes-dashboard

  annotations:

    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"

spec:

  ingressClassName: "nginx"  控制器的类型为ingress

  tls:

  - hosts:

    - k8s.dashboard.local   主机名

    secretName: dashboard-tls  这里引用创建的secrets

  rules:

  - host: k8s.dashboard.local

    http:

      paths:

      - path: /

        pathType: Prefix   起始与根都进行代理。

        backend:

          service:

            name: kubernetes-dashboard   service名称

            port:     后端端口

              number: 443

加载配置文件

# kubectl apply -f ingress-dashboard.yaml

ingress.networking.k8s.io/dashboard-ingress created

2.5 检查Ingress配置文件

# kubectl describe ingress -n kubernetes-dashboard

Name:             dashboard-ingress

Namespace:        kubernetes-dashboard

Address:          xxxxx

Default backend:  default-http-backend:80 (<error: endpoints "default-http-backend" not found>)

TLS:

  dashboard-tls terminates k8s.dashboard.local

Rules:

  Host                 Path  Backends

  ----                 ----  --------

  k8s.dashboard.local    可以看到后端的服务已被代理到。

                       /   kubernetes-dashboard:443 (192.168.3.56:8443)

Annotations:           nginx.ingress.kubernetes.io/backend-protocol: HTTPS

Events:

  Type    Reason  Age               From                      Message

  ----    ------  ----              ----                      -------

  Normal  Sync    6s (x2 over 54s)  nginx-ingress-controller  Scheduled for sync

2.6 编辑本地hosts解析并访问UI

echo "xxxxx k8s.dashboard.local"  >> /etc/hosts

巴特西