k8s redis如何设计架构

设计一个Kubernetes（k8s）环境下的Redis架构需要考虑多个方面，包括高可用性、可扩展性、持久性和安全性。以下是一个基本的架构设计示例：

1. 集群模式

为了实现高可用性和负载均衡，建议使用Redis集群模式。Redis集群会自动将数据分片存储在不同的节点上，并提供自动故障转移功能。

Redis Cluster节点配置

• Master节点：负责处理写操作。
• Slave节点：负责处理读操作，并作为备份节点。

2. Kubernetes部署

在Kubernetes中部署Redis集群可以通过以下步骤实现：

2.1. 创建Redis StatefulSet

StatefulSet是Kubernetes中用于管理有状态应用的工具，适合部署Redis集群。

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: redis-cluster
spec:
  serviceName: "redis-cluster"
  replicas: 3
  selector:
    matchLabels:
      app: redis-cluster
  template:
    metadata:
      labels:
        app: redis-cluster
    spec:
      containers:
      - name: redis
        image: redis:latest
        ports:
        - containerPort: 6379
        volumeMounts:
        - name: redis-storage
          mountPath: /data
      volumes:
      - name: redis-storage
        persistentVolumeClaim:
          claimName: redis-pvc
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: redis-pvc
spec:
  accessModes: [ "ReadWriteOnce" ]
  resources:
    requests:
      storage: 10Gi

2.2. 创建Headless Service

为了使StatefulSet中的Pod可以直接通过其名称进行通信，需要创建一个Headless Service。

apiVersion: v1
kind: Service
metadata:
  name: redis-cluster-service
spec:
  clusterIP: None
  selector:
    app: redis-cluster
  ports:
  - protocol: TCP
    port: 6379
    targetPort: 6379

3. 配置持久化存储

为了确保数据在节点重启后不会丢失，需要配置持久化存储。可以使用PersistentVolumes (PV) 和 PersistentVolumeClaims (PVC) 来实现。

4. 配置监控和日志

为了确保Redis集群的稳定运行，需要配置监控和日志收集。可以使用Prometheus和Grafana进行监控，使用ELK（Elasticsearch, Logstash, Kibana）堆栈进行日志收集。

4.1. Prometheus和Grafana

可以创建一个Prometheus Deployment和一个Grafana Deployment来监控Redis集群。

apiVersion: apps/v1
kind: Deployment
metadata:
  name: prometheus
spec:
  replicas: 1
  selector:
    matchLabels:
      app: prometheus
  template:
    metadata:
      labels:
        app: prometheus
    spec:
      containers:
      - name: prometheus
        image: prom/prometheus:latest
        ports:
        - containerPort: 9090
        volumeMounts:
        - name: prometheus-storage
          mountPath: /prometheus
      volumes:
      - name: prometheus-storage
        persistentVolumeClaim:
          claimName: prometheus-pvc
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: prometheus-pvc
spec:
  accessModes: [ "ReadWriteOnce" ]
  resources:
    requests:
      storage: 10Gi

4.2. ELK堆栈

可以创建一个Elasticsearch Deployment、一个Logstash Deployment和一个Kibana Deployment来收集和展示日志。

apiVersion: apps/v1
kind: Deployment
metadata:
  name: elasticsearch
spec:
  replicas: 1
  selector:
    matchLabels:
      app: elasticsearch
  template:
    metadata:
      labels:
        app: elasticsearch
    spec:
      containers:
      - name: elasticsearch
        image: docker.elastic.co/elasticsearch/elasticsearch:7.10.1
        ports:
        - containerPort: 9200
        volumeMounts:
        - name: elasticsearch-storage
          mountPath: /data
      volumes:
      - name: elasticsearch-storage
        persistentVolumeClaim:
          claimName: elasticsearch-pvc
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: elasticsearch-pvc
spec:
  accessModes: [ "ReadWriteOnce" ]
  resources:
    requests:
      storage: 10Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: logstash
spec:
  replicas: 1
  selector:
    matchLabels:
      app: logstash
  template:
    metadata:
      labels:
        app: logstash
    spec:
      containers:
      - name: logstash
        image: docker.elastic.co/logstash/logstash:7.10.1
        ports:
        - containerPort: 5044
        volumeMounts:
        - name: logstash-storage
          mountPath: /data
      volumes:
      - name: logstash-storage
        persistentVolumeClaim:
          claimName: logstash-pvc
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: kibana
spec:
  replicas: 1
  selector:
    matchLabels:
      app: kibana
  template:
    metadata:
      labels:
        app: kibana
    spec:
      containers:
      - name: kibana
        image: docker.elastic.co/kibana/kibana:7.10.1
        ports:
        - containerPort: 5601
        volumeMounts:
        - name: kibana-storage
          mountPath: /data
      volumes:
      - name: kibana-storage
        persistentVolumeClaim:
          claimName: kibana-pvc
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: kibana-pvc
spec:
  accessModes: [ "ReadWriteOnce" ]
  resources:
    requests:
      storage: 10Gi

5. 配置安全

为了确保Redis集群的安全性，可以采取以下措施：

• 使用网络策略限制访问。
• 配置TLS加密通信。
• 使用密码认证。

5.1. 网络策略

可以创建一个NetworkPolicy来限制对Redis集群的访问。

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: redis-network-policy
spec:
  podSelector:
    matchLabels:
      app: redis-cluster
  policyTypes:
  - Ingress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          role: client

5.2. TLS加密通信

可以使用CertManager来自动管理TLS证书，并配置Redis使用TLS加密通信。

apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: redis-tls
spec:
  secretName: redis-tls-secret
  issuerRef:
    kind: Issuer
    name: letsencrypt-prod
  commonName: redis-cluster
  dnsNames:
  - redis-cluster

然后在Redis配置文件中启用TLS：

ssl on
ssl_cert_reqs preserver
ssl_cafile /etc/ssl/certs/ca-certificates.crt
ssl_keyfile /etc/ssl/private/redis.key
ssl_verify_mode verify_peer

总结

以上是一个基本的Kubernetes环境下Redis集群的架构设计示例。实际部署时，还需要根据具体需求进行调整和优化。