Redis - Cluster Setup

Prerequisites

• Redis cluster supported from version 1.2.4 in @appveen/utils (https://github.com/appveen/utils)

Environment Variables

• REDIS_CLUSTER

Comma separated host and port details. Eg: 127.0.0.1,127.0.0.2:8990 results in 127.0.0.1:6379 and 127.0.0.2:8990 respectively

Deploy Redis

1. Clone the setup repo (https://github.com/appveen/setup-redis-cluster)

2. Update the redis image and port details in redis-sts.yaml and redis-svc.yaml.

3. If deploying redis without MOUNT , remove the below one from redis-sts.yaml

Volume Mount:- name: data

     mountPath: /data

     readOnly: false

Volumes:

     - name: data

     hostPath:

path: /mnt/redis

4. Execute install.sh from the downloaded repo. (Specify the k8s namespace and cluster size as prompted). 

5. Minimum size: 6. Master - 3 and slave -3

6. Once install.sh has executed successfully, we can see the pods created like below
   redis-cluster-0, redis-cluster-1 … redis-cluster-5 .

Setting up Redis-Cluster

Now, we are going to set up a cluster by executing the below commands one by one.

Replace the _namespace_ with yours.

1. Get the  IP  address of the redis-cluster pods.
   
   

   kubectl get pods -l app=redis-cluster -o jsonpath='{range.items[*]}{.status.podIP}:6379 ' -n _namespace_

   
   

2. Create a cluster between the pods.
   
   

kubectl exec -it redis-cluster-0 -n _namespace_ -- redis-cli --cluster create --cluster-replicas 1 $(kubectl get pods -l app=redis-cluster -o jsonpath='{range.items[*]}{.status.podIP}:6379 ' -n _namespace_)

3. Get the cluster information

kubectl exec -it -n _namespace_ redis-cluster-0 -- redis-cli cluster info

4. Verify the master and slaves are connected successfully.

for x in $(seq 0 5); do echo "redis-cluster-$x"; kubectl exec redis-cluster-$x -n _namespace_ -- redis-cli role; echo; done