kubernetes生產實踐之redis-cluster
阿新 • • 發佈：2021-03-10
##方案一 自定義yaml檔案安裝redis cluster
### 背景
在Kubernetes中部署Redis叢集面臨挑戰，因為每個Redis例項都依賴於一個配置檔案，該檔案可以跟蹤其他叢集例項及其角色。為此，需要結合使用Kubernetes StatefulSets和PersistentVolumes實現。
redis cluster架構示意圖：
### 建立StatefulSet yaml檔案
```
---
apiVersion: v1
kind: ConfigMap
metadata:
name: redis-cluster
data:
update.sh: |
#!/bin/sh
REDIS_NODES="/data/nodes.conf"
sed -i -e "/myself/ s/[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}/${POD_IP}/" ${REDIS_NODES}
exec "$@"
redis.conf: |+
bind 0.0.0.0
cluster-enabled yes
cluster-require-full-coverage no
cluster-node-timeout 30000
cluster-config-file /data/nodes.conf
cluster-migration-barrier 1
appendonly yes
protected-mode no
---
apiVersion: apps.kruise.io/v1beta1
# apiVersion: apps/v1
kind: StatefulSet
metadata:
name: redis-cluster
spec:
serviceName: redis-cluster
replicas: 6
selector:
matchLabels:
app: redis-cluster
template:
metadata:
labels:
app: redis-cluster
spec:
containers:
- name: redis
image: redis:6.2.1-alpine
ports:
- containerPort: 6379
name: client
- containerPort: 16379
name: gossip
command: ["/conf/update.sh", "redis-server", "/conf/redis.conf"]
env:
- name: POD_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
volumeMounts:
- name: conf
mountPath: /conf
readOnly: false
- name: data
mountPath: /data
readOnly: false
volumes:
- name: conf
configMap:
name: redis-cluster
defaultMode: 0755
volumeClaimTemplates:
- metadata:
name: data
spec:
accessModes: [ "ReadWriteOnce" ]
resources:
requests:
storage: 100Gi
storageClassName: rbd
```
註釋：
```
cluster-migration-barrier 那些分配後仍然剩餘migration barrier個從節點的主節點才會觸發節點分配，而不是分配前有migration barrier個從節點的主節點就會觸發節點分配，預設是1，生產環境建議維持預設值
protected-mode no 引數是為了禁止外網訪問redis，如果啟用了，則只能夠通過lookback ip（127.0.0.1）訪問Redis，如果外網訪問redis，會報出異常。
apiVersion: apps.kruise.io/v1beta1 控制器這裡使用kruise提供的Advanced StatefulSet，如果叢集沒有安裝kruise，可以使用 apps/v1
```
### 安裝redis-cluster
```
[root@qd01-stop-k8s-master001 redis]# kubectl apply -f install-redis.yaml
configmap/redis-cluster created
statefulset.apps.kruise.io/redis-cluster created
[root@qd01-stop-k8s-master001 redis]# kubectl get po -n op
NAME READY STATUS RESTARTS AGE
redis-cluster-0 1/1 Running 0 3m26s
redis-cluster-1 1/1 Running 0 3m14s
redis-cluster-2 1/1 Running 0 2m54s
redis-cluster-3 1/1 Running 0 2m23s
redis-cluster-4 1/1 Running 0 2m14s
redis-cluster-5 1/1 Running 0 114s
```
### 建立redis-cluster service
```
---
apiVersion: v1
kind: Service
metadata:
name: redis-cluster
namespace: op
spec:
type: ClusterIP
ports:
- port: 6379
targetPort: 6379
name: client
- port: 16379
targetPort: 16379
name: gossip
selector:
app: redis-cluster
```
```
[root@qd01-stop-k8s-master001 redis]# kubectl apply -f redis-svc.yml
service/redis-cluster created
[root@qd01-stop-k8s-master001 redis]# kubectl get svc -n op
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
redis-cluster ClusterIP 10.97.19