ilil/k8s-redis-ha repository overview

⁠Kubernetes Redis with High Availability

Kubernetes Redis Images and Samples implemented using the latest features:

• StatefulSet
• Init Container

⁠Requirements

• Kubernetes 1.6.* cluster
• Redis 3.2

⁠Quick Start

If you have already a Kubernetes cluster, you can deploy High Availability Redis using the command below:

$ kubectl create -f example/
service "redis-sentinel" created
statefulset "redis-sentinel" created
service "redis-server" created
statefulset "redis-server" created

⁠Accessing redis

The way to access Redis in the cluster is to create a pod like below:

$ kubectl create -f test/console.yaml
pod "console" created

And the pod "console" based on library/redis⁠, so you can access Redis through the pod "console" using kubectl exec -ti console /bin/bash:

$ export MASTER_IP="$(kubectl exec console -- redis-cli -h redis-sentinel -p 26379 sentinel get-master-addr-by-name mymaster | head -1)"
$ export SERVER_PASS="_redis-server._tcp.redis-server.default.svc.cluster.local"
$ # set foo=bar 
$ kubectl exec console -- redis-cli -h "${MASTER_IP}" -a "${SERVER_PASS}" set foo bar
OK
$ # get foo
$ kubectl exec -- redis-cli -h redis-server -a "${SERVER_PASS}" get foo 
bar

If you aren't on 'default' namespace, please replace default in $SERVER_PASS with your namespace:

$ # if your namespace is 'abcde' ...
$ export SERVER_PASS="_redis-server._tcp.redis-server.abcde.svc.cluster.local"

⁠Scale in out

tarosky/k8s-redis-ha has abilities to scale in and scale out. You can check this feature below:

kubectl scale --replicas=5 statefulset/redis-sentinel
kubectl scale --replicas=5 statefulset/redis-server

⁠Sample code in Python to use High Availability Redis

One of the simplest way to access Redis in cluster is port-foward which connects a local port with a remote container port:

$ kubectl port-forward redis-server-0 6379:6379
Forwarding from 127.0.0.1:6379 -> 6379
Forwarding from [::1]:6379 -> 6379

'redis-server-0' is a Pod which are created from StatefulSet. Here is the sample code on ipython which access Redis through redis-py. To run code below, you must install redis-py⁠:

In [1]: from redis import StrictRedis

In [2]: a = StrictRedis(password='_redis-server._tcp.redis-server.default.svc.cluster.local')

In [3]: a.get('foo')
Out[3]: b'bar'

⁠Running test script

To check if Pods and others generated from example/ and images/ have High Availability, Test script is in test/. Test script requires Python virtual environment to run it. Here is an example how to build test environment.

$ pyvenv .venv
$ source .venv/bin/activate
$ pip install -r test/requirements.txt

You can run test command using command below.

$ KUBE_NAMESPACE='{{Your name space}}' nosetests test/test.py