前提摘要

• 主机安装： prometheus 监控插件

• Slave 镜像：980315926pxm/redis-slave:3.0.3

• Master 镜像：980315926pxm/redis-master:2.8.9

目录结构

• 1. 编写 redis-master-rc.yaml （ReplicationController）

• 2. 编写 redis-slave-rc.yaml（ReplicationController）

• 3. 编写 redis-svc.yaml （Service）

• 4. 部署安装集群

• 5. 验证主从同步

• 6. 集群手动伸缩扩容

• 7. 集群自动伸缩扩容

1. 编写 redis-master-rc.yaml （ReplicationController）

apiVersion: v1
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: redis-master
        image: 980315926pxm/redis-master:2.8.19
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 6379

2. 编写 redis-slave-rc.yaml

apiVersion: v1
kind: ReplicationController
metadata:
  name: redis-slave
  labels:
    name: redis-slave
spec:
  replicas: 1
  selector:
    name: redis-slave
  template:
    metadata:
      labels:
        name: redis-slave
    spec:
      containers:
      - name: redis-slave
        image: 980315926pxm/redis-slave:3.0.3
        imagePullPolicy: IfNotPresent
        resources:
          requests:
            memory: 128Mi
            cpu: 100m
          limits:
            memory: 256Mi
            cpu: 200m
        ports:
        - containerPort: 6379
        env:
        - name: GET_HOSTS_FROM
          value: env

• redis-slave 镜像中启动脚本 /run.sh 内容：

root@redis-slave-68tcm:~# cat /run.sh

if [[ ${GET_HOSTS_FROM:-dns} == "env" ]]; then
  redis-server --slaveof ${REDIS_MASTER_SERVICE_HOST} 6379
else
  redis-server --slaveof redis-master 6379
fi

3. 编写 redis-svc.yaml （Service）

apiVersion: v1
kind: Service
metadata:
  name: redis-master
  labels:
    name: redis-master
spec:
  type: NodePort
  ports:
    - port: 6379
      targetPort: 6379
      nodePort: 30009
  selector:
    name: redis-master
---

apiVersion: v1
kind: Service
metadata:
  name: redis-slave
  labels:
    name: redis-slave
spec:
  type: NodePort
  ports:
    - port: 6379
      nodePort: 30099
  selector:
    name: redis-slave

• master 主机外网连接端口 30009 (读写)

• slave 从机外网连接端口 30099（读）

4. 部署安装集群

kubectl create -f redis-master-rc.yaml
kubectl create -f redis-slave-rc.yaml
kubectl create -f redis-svc.yaml

5. 验证主从同步

root@VM-0-6-ubuntu:~# kubectl get po
NAME                 READY   STATUS    RESTARTS   AGE
mysql-master-99mpz   1/1     Running   0          128m
mysql-slave-rfc45    1/1     Running   0          128m
redis-master-hxnqs   1/1     Running   0          15m
redis-slave-v6tcm    1/1     Running   0          26m

root@VM-0-6-ubuntu:~# kubectl exec -it redis-master-hxnqs -- bash
[ root@redis-master-hxnqs:/data ]$ redis-cli
127.0.0.1:6379> set test 123456
OK

root@VM-0-6-ubuntu:~# kubectl exec -it redis-slave-v6tcm -- bash
root@redis-slave-v6tcm:/data# redis-cli
127.0.0.1:6379> get test
"123456"

image.png

6. 集群手动伸缩扩容

root@VM-0-6-ubuntu:~# kubectl scale rc redis-slave --replicas=3
replicationcontroller/redis-slave scaled
root@VM-0-6-ubuntu:~# kubectl get pods
NAME                 READY   STATUS    RESTARTS   AGE
mysql-master-99mpz   1/1     Running   0          142m
mysql-slave-rfc45    1/1     Running   0          142m
redis-master-hxnqs   1/1     Running   0          30m
redis-slave-68v4c    1/1     Running   0          58s
redis-slave-t9zkc    1/1     Running   0          58s
redis-slave-v6tcm    1/1     Running   0          40m

image.png

7. 集群自动伸缩扩容

root@VM-0-6-ubuntu:~# kubectl autoscale rc redis-slave --min=1 --max=10 --cpu-percent=50
horizontalpodautoscaler.autoscaling/redis-slave autoscaled
root@VM-0-6-ubuntu:~# kubectl get hpa
NAME          REFERENCE                           TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
redis-slave   ReplicationController/redis-slave   0%/50%    1         10        1          7m20s

• kubectl autoscale rc redis-slave --min=1 --max=10 --cpu-percent=50

  --min （容器数量下限）
  --max （容器数量上限）
  --cpu-percent （cpu使用率达到指定百分比）
  容器 cpu 使用率上升至 50% 以上时，自动扩充容器数量
  容器 cpu 使用率下降至 50% 以上时，自动缩减容器数量