Redis Operator - An easy way of deploying Redis on Kubernetes

This is Redis Operator which will create/manage Redis on the top of the Kubernetes. The project is inspired by the Operator Framework which is initiated by the CoreOS.

Requirements

Golang

• If you want to do development

Kubernetes 1.9+

• This operator supports Kubernetes 1.9+ versions

Overview

Redis Operator deploy and manage the Redis instances in form of cluster or Master and Slave depending upon on your configuration

Things you should know about Redis Operator:-

• 3 is a minimum number of Redis instances.
• Redis 5.0 is the minimum supported version.
• Redis Operator is not a distributed system. It leverages a simple leader election protocol. You can run multiple instances of Redis Operator.

The folder structure of operator is something like this:-

redis-operator      ---> Main codebase directory for Redis Operator
├── build           ---> All the artifacts(binary) and Dockerfile
├── cmd             ---> Contains main.go which is the entry point to initialize and start this operator
├── deploy          ---> Contains manifests for deploying operator on kubernetes cluster
├── example         ---> Example file for deploying redis cluster
├── go.mod          ---> Go module file for dependency management
├── Gopkg.lock      ---> Lock file generated by dep for dependency management
├── Gopkg.toml      ---> Main dep file for managing go dependencies with dep
├── LICENSE         ---> Apache-2.0 License for this operator
├── pkg             ---> Contains main api and controller files for operator operations
├── vendor          ---> The golang vendor directory contains the local copies of external dependencies
└── version         ---> This directory have the version information of this operator

Getting Started

Deploying Redis Operator

• Create a namespace for redis-operator

kubectl create namespace redis-operator

• Deploy the CRDs and Operator in redis-operator namespace

kubectl apply -Rf deploy

• Check if operator is running fine or not

kubectl -n redis-operator get deployment
kubectl get pods -n redis-operator

Deploying Redis

• Redis can be deployed by creating a Redis Custom Resource(CR).
• Create a Redis CR that deploys a 3 node Redis replication in high availablilty mode:

kubectl create -f example/deployment.yaml

• Wait until the redis pods are up. It will show the name for the Pod of the current master instance and the total number of replicas in the setup:

kubectl get redis example -n redis-operator

• Scale the deployment:

kubectl scale redis example --replicas 4 -n redis-operator
redis.opstree.com/example scaled

kubectl get redis example -n redis-operator
NAME      MASTER            REPLICAS   DESIRED   AGE
example   redis-example-0   4          4         24d

What Redis Operator provides you?

Redis Operator creates the following resources owned by the corresponding Redis.

Kubernetes API

• redis.opstree.com

Secret

• In case password setup is enable

ConfigMap

• For Redis Configuration Management

PodDisruptionBudget

• For managing the Disruptions

StatefulSet

• StatefulSets for redis cluster deployment

Services

• For communication with redis in kubernetes cluster
  • redis-example ---> covers all pods
  • redis-example-master ---> service for access to master pod

To Do

• Implement CI pipeline for this code.
• Add the Design and Goal information in the README.
• Create test cases for the operator