Redis Cluster on Kubernetes

This repository contains Kubernetes configuration files to deploy a Redis cluster using Kubernetes. The setup includes a ConfigMap for Redis configuration, a headless Service for DNS-based service discovery, a StatefulSet for managing Redis replicas, and PersistentVolumeClaims (PVCs) for data storage.

Prerequisites

Before deploying the Redis cluster, ensure you have the following prerequisites installed:

• Kubernetes cluster up and running.
• kubectl command-line tool configured to access your cluster.

Configuration

The Redis cluster is configured using a ConfigMap named redis-config. The redis.conf file in this ConfigMap contains the Redis server configuration. You can customize this file to suit your requirements. Here's the default configuration:

bind 0.0.0.0
port 6379
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes
# requirepass YOUR_REDIS_PASSWORD

Deployment

To deploy the Redis cluster, follow these steps:

1. Apply the ConfigMap containing the Redis configuration:

kubectl apply -f redis-config.yaml

2. Create the headless Service for Redis:

kubectl apply -f redis-cluster-service.yaml

3. Deploy the StatefulSet for Redis replicas:

kubectl apply -f redis-cluster-statefulset.yaml

Dockerfile

The Dockerfile provided in this repository extends the official Redis image. It copies the custom redis.conf file into the image and uses it as the configuration for the Redis server. You can build and push this Docker image to your container registry if needed.

Scaling

You can scale the number of Redis replicas by updating the replicas field in the redis-cluster-statefulset.yaml file and then applying the changes:

kubectl apply -f redis-cluster-statefulset.yaml

Data Persistence

Data persistence is ensured by using PersistentVolumeClaims (PVCs). Each Redis replica has its own PVC named redis-data with a default requested storage size of 30MiB. You can modify the storage size in the redis-cluster-statefulset.yaml file to meet your storage requirements.

Accessing Redis

To access the Redis cluster, you can use the headless Service redis-cluster-service with DNS-based discovery. For example, to connect to the first Redis pod:

redis-cli -h redis-cluster-0.redis-cluster-service

Maintenance

To update the Redis configuration, modify the redis.conf file in the redis-config.yaml ConfigMap. Changes will take effect upon restarting the Redis pods. You can perform rolling restarts by deleting and recreating pods or using Kubernetes rolling updates.

Feel free to customize this setup according to your specific needs and requirements.