使用Kubernetes创建PHP留言板系统

本文将演示使用kubernetes系统基于 kubeguide相关的镜像文件创建基于php和redis的留言板系统，因为系统资源有限，kubernetes集群只有一个master节点和slave节点。
Docker本地仓库与kubernetes集群配置请查看前文。

一、环境介绍
操作系统版本：centos linux 7.2 64bit
Master节点：192.168.115.5/24 ?vm1
Slave节点1：192.168.115.6/24 ?vm2

访问流程图如下：

二、在线下载相关的镜像文件，并纳入本地仓库统一管理

# 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

三、配置文件准备
1、创建redis-master rc和service配置文件

# cat redis-master-controller.yaml apiVersion: v1kind: ReplicationControllermetadata: ?name: redis-masterspec: ?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: v1kind: Servicemetadata: ?name: redis-master ?labels: ???name: redis-masterspec: ?ports: ?- port: 6379 ???targetPort: 6379 ?selector:name: redis-master

2、创建redis-slave的rc和service配置文件

# cat redis-slave-controller.yamlapiVersion: v1kind: ReplicationControllermetadata: ?name: redis-slavespec: ?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: v1kind: Servicemetadata: ?name: redis-slave ?labels: ???name: redis-slavespec: ?ports: ?- port: 6379 ?selector:name: redis-slave

3、创建frontend的rc和service配置文件

# cat frontend-controller.yamlapiVersion: v1kind: ReplicationControllermetadata: ?name: frontend ?labels: ???name: frontendspec: ?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.yamlapiVersion: v1kind: Servicemetadata: ?name: frontend ?labels: ???name: frontendspec: ?type: NodePort ?ports: ?- port: 80 ???nodePort: 30001 ?selector:name: frontend

四、在master节点上创建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

无法创建pod的原因主要是无法从本地仓库中拉取镜像，即使本地已经存在了这个镜像，也是报这个错误。因为kubernetes的imagePullPolicy获取镜像策略默认值为Always

我们本地仓库的nginx配置了basic验证，故而报错如下
Error syncing pod, skipping: failed to "StartContainer" for "redis-slave" with ErrImagePull: "unauthorized: authentication required" ?
关闭nginx basic认证之后，再尝试一次，果然没有问题。

在Kubernetes中使用私有仓库并支持basic认证的最终解决方案是去配置kubernetes的serviceaccount，关于详细的配置将在后续的文章中进行介绍。

六、测试
1、查看redis master节点的redis集群信息

# 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" 

2、web测试

通过firebug插件可以看到是php+apache在提供web服务

七、 rc和service的删除

# 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

使用Kubernetes创建PHP留言板系统

原文地址：http://blog.51cto.com/ylw6006/2067250