k8s入门系列之guestbook快速部署

k8s集群以及一些扩展插件已经安装完毕，本篇文章介绍一下如何在k8s集群上快速部署guestbook应用。

•实验环境为集群：master(1)+node(4),详细内容参考《k8s入门系列之集群安装篇》

•guestbook应用示例介绍：
应用包含2部分：web前端和redis(1主2从),用户通过web前端提交数据，写入到redis-master上，然后通过读取同步到redis-slave上的数据展示给用户。

提示：所有的定义文件都存放在master端，所有的操作也都是在master端操作。

实验:

1.配置启动redis-master服务
•编辑redis-master-rc.yml定义文件
[root@master guestbook]# cat redis-master-rc.yml

kind: ReplicationController
metadata:
  name: redis-master
  labels:
    name: redis-master
spec:
  replicas: 1
  selector:
    name: redis-master
  template:
    metadata:
      labels:
        name: redis-master
    spec:
      containers:
      - name: master
        image: docker.gaoxiaobang.com/kubernetes/redis
        ports:
        - containerPort: 6379

•创建Pod

[root@master guestbook]# kubectl create -f redis-master-rc.yml
replicationcontroller "redis-master" created

•查看rc(ReplicationController)

[root@master guestbook]# kubectl get rc -l name=redis-master
NAME DESIRED CURRENT AGE
redis-master 1 1 29s

•查看Pod

[root@master guestbook]# kubectl get pods -o wide
NAME                     READY     STATUS    RESTARTS   AGE       NODE
redis-master-7tt3s       1/1       Running   0          15m       192.168.30.21

Kubernetes中Service中起到了负载均衡器的作用，通过Proxy和Selector决定服务请求传递给后端提供服务的Pod，对外提供固定的IP,这样的话Redis Master Pod迁移变化也不会影响。

•编辑redis-master-svc.yml定义文件
[root@master guestbook]# cat redis-master-svc.yml

apiVersion: v1
kind: Service
metadata:
  name: redis-master
  labels:
    name: redis-master
spec:
  ports:
  - port: 6379
    targetPort: 6379
  selector:
    name: redis-master

•创建Service

[root@master guestbook]# kubectl create -f redis-master-svc.yml

•查看Service

[root@master guestbook]# kubectl get svc redis-master
NAME           CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
redis-master   10.254.59.45   <none>        6379/TCP   3m

2.配置启动redis-slave服务
•编辑redis-slave-rc.yml定义文件
[root@master guestbook]# cat redis-slave-rc.yml

apiVersion: v1
kind: ReplicationController
metadata:
  name: redis-slave
  labels:
    name: redis-slave
spec:
  replicas: 2
  selector:
    name: redis-slave
  template:
    metadata:
      labels:
        name: redis-slave
    spec:
      containers:
      - name: worker
        image: docker.gaoxiaobang.com/kubernetes/redis-slave
        ports:
        - containerPort: 6379

•创建Pod

[root@master guestbook]# kubectl create -f redis-slave-rc.yml
replicationcontroller "redis-slave" created

•查看rc

[root@master guestbook]# kubectl get rc redis-slave
NAME          DESIRED   CURRENT   AGE
redis-slave   2         2         1m

•查看Pod

[root@master guestbook]# kubectl get pod -o wide
NAME                     READY     STATUS    RESTARTS   AGE       NODE
redis-master-7tt3s       1/1       Running   0          15m       192.168.30.21
redis-slave-drxok        1/1       Running   0          15m       192.168.30.23
redis-slave-h43yo        1/1       Running   0          15m       192.168.30.21

•编辑redis-slave-svc.yml定义文件
[root@master guestbook]# cat redis-slave-svc.yml

apiVersion: v1
kind: Service
metadata:
  name: redis-slave
  labels:
    name: redis-slave
spec:
  ports:
  - port: 6379
    targetPort: 6379
  selector:
    name: redis-slave

•创建Service

[root@master guestbook]# kubectl create -f redis-slave-svc.yml
service "redis-slave" created

•查看Service

[root@master guestbook]# kubectl get svc redis-slave
NAME          CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
redis-slave   10.254.172.53   <none>        6379/TCP   19m

3.配置启动web端服务
•编辑guestbook-web-rc.yml定义文件
[root@master guestbook]# cat guestbook-web-rc.yml

apiVersion: v1
kind: ReplicationController
metadata:
  name: guestbook-web
  labels:
    name: guestbook-web
spec:
  replicas: 2
  selector:
    name: guestbook-web
  template:
    metadata:
      labels:
        name: guestbook-web
    spec:
      containers:
      - name: php-redis
        image: docker.gaoxiaobang.com/kubernetes/guestbook-web
        ports:
        - containerPort: 80

•创建Pod

[root@master guestbook]# kubectl create -f guestbook-web-rc.yml
replicationcontroller "guestbook-web" created

•查看rc

[root@master guestbook]# kubectl get rc guestbook-web
NAME            DESIRED   CURRENT   AGE
guestbook-web   2         2         18m

•查看Pod

[root@master guestbook]# kubectl get pods
NAME                     READY     STATUS    RESTARTS   AGE
guestbook-web-1un8o      1/1       Running   0          34m
guestbook-web-iyxpg      1/1       Running   0          34m
gxb-web-rc-afi56         1/1       Running   0          10d
redis-master-7tt3s       1/1       Running   0          38m
redis-slave-drxok        1/1       Running   0          37m
redis-slave-h43yo        1/1       Running   0          37m

•编辑guestbook-web-svc.yml定义文件
[root@master guestbook]# cat guestbook-web-svc.yml

apiVersion: v1
kind: Service
metadata:
  name: guestbook-web
  labels:
    name: guestbook-web
spec:
  type: NodePort
  ports:
  - port: 80
  selector:
    name: guestbook-web

•创建Service

You have exposed your service on an external port on all nodes in your
cluster. If you want to expose this service to the external internet, you may
need to set up firewall rules for the service port(s) (tcp:520) to serve traffic.

See http://releases.k8s.io/release-1.2/docs/user-guide/services-firewalls.md for more details.
service "guestbook-web" created

*提示：在集群所有node节点上都开启了520端口，访问任何一个node的520端口都可以。例如：192.168.30.21:520

•查看Service

[root@master guestbook]# kubectl get svc guestbook-web
NAME            CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
guestbook-web   10.254.225.216   nodes         80/TCP    34m

4.访问guestbook，如下图

参考文章:

http://dockone.io/article/542