Running Redis Cluster on OpenShift 3.1

Overview

This repository will containerize Redis and Sentinel to run Redis Cluster on OpenShift 3. Each Pod will have two containers (Redis and Sentinel) and can be easily scaled up/down as required.

Bill of Materials

• Environment: It has been built and ran on OpenShift 3.1
• Template files: None at this moment
• Config files: Individual files has been prepared and can be cloned
• External Source Code repos: Any application can be integrated with Redis Cluster

Setup Instructions

Please follow the steps to build a Redis Cluster:

1. Cloning and preparing Dockerfile

1.1) Clone the repository:

    mkdir ~/redis-sentinel; cd ~/redis-sentinel/
    git clone https://github.com/shah-zobair/redis-sentinel.git
```

1.2) Prepare the Docker image:

```
    cd image/
    chmod 777 run.sh
    docker build -t redis2 .
    docker build -t redis-sentinel .

2. Push to OpenShift Registry

2.1) Push the newly created Images (redis2 and redis-sentinel to OSE Registry)

   oc login -u system:admin
   oc project default
   oc get service **(Note the Registry Service IP and Port)**
```

2.2) Tag the Docker images and Create new Image Streams for both images: 

```
   docker tag redis2 <Registry_IP>:<Registry_Port>/openshift/redis2
   docker tag redis-sentinel <Registry_IP>:<Registry_Port>/openshift/redis-sentinel
   oc create -f image_stream.json -n openshift
   oc create -f image_stream-sentinel.json -n openshift

2.3) Provide a Regular user to Build, Pull and Deploy Images into OSE Registry:

oadm policy add-role-to-user system:image-builder <Regular_Username> -n openshift
oadm policy add-role-to-user system:image-puller <Regular_Username> -n openshift
oadm policy add-role-to-user system:deployer <Regular_Username> -n openshift

2.4) Push Docker Images to registry being a regular user:

oc login -u <Regular_Username>
oc whoami -t **(Note the generated Token)**
docker login -u <Regular_Username> -e a@b.com -p <generated_Token> <Registry_IP>:<Registry_Port>
docker push <Registry_IP>:<Registry_Port>/openshift/redis2
docker push <Registry_IP>:<Registry_Port>/openshift/redis-sentinel

2.5) Verify Images in the OSE Registry:

oc login -u system:admin
oc get images | grep redis

3. Preparing NFS Persistent Volumes

3.1) Create two NFS directories for Redis and Sentinel Containers in the NFS Server:

mkdir /opt/nfs/red
chown nfsnobody.nfsnobody /opt/nfs/red
chown -R nfsnobody.nfsnobody /opt/nfs/red
chmod 775 /opt/nfs/red

mkdir /opt/nfs/redis-sentinel
chown nfsnobody.nfsnobody /opt/nfs/redis-sentinel
chown -R nfsnobody.nfsnobody /opt/nfs/redis-sentinel
chmod 775 /opt/nfs/redis-sentinel

3.2) Export as:

(In /etc/exports)
/opt/nfs/red node00-640a.oslab.opentlc.com(all_squash,rw,sync) node01-640a.oslab.opentlc.com(all_squash,rw,sync)
/opt/nfs/redis-sentinel node00-640a.oslab.opentlc.com(all_squash,rw,sync) node01-640a.oslab.opentlc.com(all_squash,rw,sync)

exportfs -a

4. Create Objetcs:

4.1) Create new project, pods, Services, Controllers for the Cluster:

oc new-project redis --display-name="Redis Sentinal Cluster" --description="This is the project of Redis Assignment"

oc create -f redis-master-new.yaml
oc create -f redis-sentinel-service.yaml
oc create -f redis-service.yaml
oc create -f redis-controller-new.yaml
oc create -f redis-sentinel-controller-new.yaml
oc create -f deploymentconfig-new.json

4.2) Create Persistent Volume for the Pods:

oc login -u system:admin
oc create -f volume_red.yaml
oc create -f claim_red.yaml
oc volume deploymentconfigs/redis --add --overwrite --name=myclaim2 --mount-path=/redis-master-data --source='{"nfs": { "server": "nfs00-640a", "path": "/opt/nfs/red" }}'

oc create -f volume_redis-sentinel.yaml
oc create -f claim_redis-sentinel.yaml
oc volume deploymentconfigs/redis --add --overwrite --name=myclaim3 --mount-path=/redis-sentinel-data --source='{"nfs": { "server": "nfs00-640a", "path": "/opt/nfs/redis-sentinel" }}'

4.3) Scale up to test:

oc scale rc redis --replicas=3
oc scale rc redis-sentinel --replicas=3

Now applications can be connected using rediss-setinel Cluster IP. (oc get service redis-sentinel)

Wiki Link