【Kubernetes学习之三】Kubernetes分布式集群架构

环境
　　centos 7

一、Kubernetes分布式集群架构
1、Kubernetes服务注册和服务发现问题怎么解决的？
每个服务分配一个不变的虚拟IP+端口， 系统env环境变量里有每个服务的服务名称到IP的映射。

2、服务的负载均衡问题怎么解决的？
每个节点上都有一个软件实现的服务代理来实现负载均衡

3、服务的规模部署问题怎么解决的？
目标导向的做法：确定部署实例数，系统自动调度

4、服务运维问题如何解决的？
自动监控、自我修复

5、集中配置，并且实时配置实施生效

二、集群架构示例
1、示例
一个PHP做的留言板：3台webserver做PHP-Frontend前台，1台redis-master用来写,2台redis-slave做读。

2、集群搭建图
创建三个service：frontend Service、redis-master Service、redis-slave Service

三、搭建
1、创建redis-master Pod
(1)定义redis-master-controller.yaml文件：

[root@node106 ~]# vi redis-master-controller.yaml
apiVersion: v1
kind: ReplicationController
metadata:
  name: redis-master
  labels:
    name: redis-master
spec:
  replicas:
  selector:
    name: redis-master
  template:
    metadata:
      labels:
        name: redis-master
    spec:
      containers:
      - name: master
        image: kubeguide/redis-master
        ports:
        - containerPort: 

(2)执行创建命令

[root@node106 ~]# kubectl create -f redis-master-controller.yaml
replicationcontroller/redis-master created

(3)查看pod

[root@node106 ~]# kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
redis-master-659bm       /     Running             4m46s

2、创建redis-master 服务

(1)定义redis-master-service.yaml

[root@node106 ~]# vi redis-master-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: redis-master
  labels:
    name: redis-master
spec:
  ports:
  - port:
    targetPort:
  selector:
    name: redis-master

(2)执行创建命令

[root@node106 ~]# kubectl create -f redis-master-service.yaml
service/redis-master created

(3)查看服务

[root@node106 ~]# kubectl get services
NAME              TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes        ClusterIP   10.96.0.1       <none>        /TCP        46h
redis-master      ClusterIP   10.96.187.196   <none>        /TCP       18s

3、创建redis-slave Pod

(1)创建redis-slave-controller.yaml

[root@node106 ~]# vi redis-slave-controller.yaml
apiVersion: v1
kind: ReplicationController
metadata:
  name: redis-slave
  labels:
    name: redis-slave
spec:
  replicas:
  selector:
    name: redis-slave
  template:
    metadata:
      labels:
        name: redis-slave
    spec:
      containers:
      - name: slave
        image: kubeguide/guestbook-redis-slave
        env:
        - name: GET_HOSTS_FROM
          value: env
        ports:
        - containerPort: 

(2)执行创建命令

[root@node106 ~]# kubectl create -f redis-slave-controller.yaml
replicationcontroller/redis-slave created

(3)查看pod和rc

[root@node106 ~]# kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
redis-master-659bm       /     Running             16m
redis-slave-kqllg        /     Running             119s
redis-slave-rfbr8        /     Running             119s
[root@node106 ~]# kubectl get rc
NAME           DESIRED   CURRENT   READY   AGE
redis-master                            17m
redis-slave                             2m24s

4、创建redis-slave 服务

(1)创建redis-slave-service.yaml

[root@node106 ~]# vi redis-slave-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: redis-slave
  labels:
    name: redis-slave
spec:
  ports:
  - port:
  selector:
    name: redis-slave

(2)执行创建命令

[root@node106 ~]# kubectl create -f redis-slave-service.yaml
service/redis-slave created

(3)查看服务

[root@node106 ~]# kubectl get services
NAME              TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes        ClusterIP   10.96.0.1       <none>        /TCP        46h
redis-master      ClusterIP   10.96.187.196   <none>        /TCP       11m
redis-slave       ClusterIP   10.99.146.233   <none>        /TCP       33s

5、创建frontend Pod

(1)创建frontend-controller.yaml

[root@node106 ~]# vi frontend-controller.yaml
apiVersion: v1
kind: ReplicationController
metadata:
  name: frontend
  labels:
    name: frontend
spec:
  replicas:
  selector:
    name: frontend
  template:
    metadata:
      labels:
        name: frontend
    spec:
      containers:
      - name: frontend
        image: kubeguide/guestbook-php-frontend
        env:
        - name: GET_HOSTS_FROM
          value: env
        ports:
        - containerPort: 

(2)执行创建命令

[root@node106 ~]# kubectl create -f frontend-controller.yaml
replicationcontroller/frontend created

(3)查看pod

[root@node106 ~]# kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
curl-6bf6db5c4f-dn65h    /     Running             41h
frontend-jjpzd           /     Running             6m50s
frontend-p2jpn           /     Running             6m50s
frontend-rm4z4           /     Running             6m50s
redis-master-659bm       /     Running             30m
redis-slave-kqllg        /     Running             15m
redis-slave-rfbr8        /     Running             15m

6、创建frontend 服务

(1)创建frontend-service.yaml

[root@node106 ~]# vi frontend-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: frontend
  labels:
    name: frontend
spec:
  type: NodePort
  ports:
  - port:
    nodePort:
  selector:
    name: frontend

(2)执行创建命令

[root@node106 ~]# kubectl create -f frontend-service.yaml
service/frontend created

(3)查看服务

[root@node106 ~]# kubectl get services
NAME              TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
frontend          NodePort    10.110.39.201   <none>        :/TCP   34s
kubernetes        ClusterIP   10.96.0.1       <none>        /TCP        46h
redis-master      ClusterIP   10.96.187.196   <none>        /TCP       24m
redis-slave       ClusterIP   10.99.146.233   <none>        /TCP       13m

验证：