使用Kubernetes建立PHP留言板系統

本文將演示使用kubernetes系統基於 kubeguide相關的鏡像文件建立基於php和redis的留言板系統，由於系統資源有限，kubernetes集羣只有一個master節點和slave節點。
Docker本地倉庫與kubernetes集羣配置請查看前文。

1、環境介紹
操做系統版本：centos linux 7.2 64bit
Master節點：192.168.115.5/24 vm1
Slave節點1：192.168.115.6/24 vm2

訪問流程圖以下：

2、在線下載相關的鏡像文件，並歸入本地倉庫統一管理

# docker pull kubeguide/redis-master # docker pull kubeguide/guestbook-php-frontend # docker pull kubeguide/guestbook-redis-slave # docker tag kubeguide/redis-master registry.fjhb.cn/redis-master # docker tag kubeguide/guestbook-php-frontend registry.fjhb.cn/guestbook-php-frontend # docker tag kubeguide/guestbook-redis-slave registry.fjhb.cn/guestbook-redis-slave # docker push registry.fjhb.cn/redis-master # docker push registry.fjhb.cn/guestbook-php-frontend # docker push registry.fjhb.cn/guestbook-redis-slave # curl -u yang:123 -XGET https://registry.fjhb.cn/v2/_catalog # docker images |grep fjhb

3、配置文件準備
一、建立redis-master rc和service配置文件

# cat redis-master-controller.yaml apiVersion: v1 kind: ReplicationController metadata: name: redis-master spec: replicas: 1 selector: name: redis-master template: metadata: name: redis-master labels: name: redis-master spec: containers: - name: redis-master image: registry.fjhb.cn/redis-master ports: - containerPort: 6379

# cat redis-master-service.yaml apiVersion: v1 kind: Service metadata: name: redis-master labels: name: redis-master spec: ports: - port: 6379 targetPort: 6379 selector: name: redis-master

二、建立redis-slave的rc和service配置文件

# cat redis-slave-controller.yaml apiVersion: v1 kind: ReplicationController metadata: name: redis-slave spec: replicas: 2 selector: name: redis-slave template: metadata: name: redis-slave labels: name: redis-slave spec: containers: - name: redis-slave image: registry.fjhb.cn/guestbook-redis-slave env: - name: GET_HOSTS_FROM value: env ports: - containerPort: 6379

# cat redis-slave-service.yaml apiVersion: v1 kind: Service metadata: name: redis-slave labels: name: redis-slave spec: ports: - port: 6379 selector: name: redis-slave

三、建立frontend的rc和service配置文件

# cat frontend-controller.yaml apiVersion: v1 kind: ReplicationController metadata: name: frontend labels: name: frontend spec: replicas: 3 selector: name: frontend template: metadata: labels: name: frontend spec: containers: - name: frontend image: registry.fjhb.cn/guestbook-php-frontend env: - name: GET_HOSTS_FROM value: env ports: - containerPort: 80

# cat frontend-service.yaml apiVersion: v1 kind: Service metadata: name: frontend labels: name: frontend spec: type: NodePort ports: - port: 80 nodePort: 30001 selector: name: frontend

4、在master節點上建立rc 和 sevices

# kubectl create -f redis-master-controller.yaml # kubectl create -f redis-slave-controller.yaml # kubectl create -f frontend-controller.yaml # kubectl create -f redis-master-service.yaml # kubectl create -f redis-slave-service.yaml # kubectl create -f frontend-service.yaml # kubectl get rc # kubectl get svc # kubectl get pod

# kubectl describe pod redis-slave-gsk1p

沒法建立pod的緣由主要是沒法從本地倉庫中拉取鏡像，即便本地已經存在了這個鏡像，也是報這個錯誤。由於kubernetes的imagePullPolicy獲取鏡像策略默認值爲Always

咱們本地倉庫的nginx配置了basic驗證，故而報錯以下
Error syncing pod, skipping: failed to "StartContainer" for "redis-slave" with ErrImagePull: "unauthorized: authentication required"
關閉nginx basic認證以後，再嘗試一次，果真沒有問題。

在Kubernetes中使用私有倉庫並支持basic認證的最終解決方案是去配置kubernetes的serviceaccount，關於詳細的配置將在後續的文章中進行介紹。

6、測試
一、查看redis master節點的redis集羣信息

# kubectl exec redis-master-9993n redis-cli info |grep -A 5 "Replication" # kubectl exec redis-slave-gnq41 redis-cli info |grep -A 5 "Replication" # kubectl exec redis-slave-nvscp redis-cli info |grep -A 5 "Replication" 

二、web測試

經過firebug插件能夠看到是php+apache在提供web服務

7、 rc和service的刪除

來自：http://blog.51cto.com/ylw6006/2067250# kubectl delete -f frontend-controller.yaml # kubectl delete -f redis-master-controller.yaml # kubectl delete -f redis-slave-controller.yaml # kubectl delete -f redis-slave-service.yaml # kubectl delete -f redis-master-service.yaml # kubectl delete -f frontend-service.yaml