Kubernetes configmap with Redis - redis

Question

I was following this tutorial to setup a configmap for a redis.conf. After I create the Redis deployment, I check to ensure that the redis.conf file is in each of the pods, and they are there. The problem is that when go in the redis-cli and check the configuration there, the redis.conf values aren't used. The default values are being used as if the Redis did not start up with the redis.conf file.
redis.conf
maxclients 2000
requirepass "test"
redis-config configmap
{
"apiVersion": "v1",
"data": {
"redis-config": "maxclients 2000\nrequirepass \"test\"\n\n"
},
"kind": "ConfigMap",
"metadata": {
"creationTimestamp": "2018-03-07T15:28:19Z",
"name": "redis-config",
"namespace": "default",
"resourceVersion": "2569562",
"selfLink": "/api/v1/namespaces/default/configmaps/redis-config",
"uid": "29d250ea-221c-11e8-969f-06c0c8d545d2"
}
}
k8 redis manifest.json
{
"kind" : "Deployment",
"apiVersion" : "extensions/v1beta1",
"metadata" : {
"name" : "redis-master",
"creationTimestamp" : null
},
"spec" : {
"replicas" : 2,
"template" : {
"metadata" : {
"creationTimestamp" : null,
"labels" : {
"app" : "redis",
"role" : "master",
"tier" : "backend"
}
},
"spec" : {
"hostNetwork" : true,
"nodeSelector" :{ "role": "cache"},
"containers" : [{
"name" : "master",
"image" : "redis",
"ports" : [{
"containerPort" : 6379,
"hostPort" : 6379,
"protocol" : "TCP"
}
],
"volumeMounts" : [{
"mountPath" : "/redis-master",
"name": "config"
}
],
"resources" : {},
"terminationMessagePath" : "/dev/termination-log",
"imagePullPolicy" : "IfNotPresent"
}],
"volumes" : [{
"name" : "config",
"configMap" : {
"name" : "redis-config",
"items": [{
"key": "redis-config",
"path": "redis.conf"
}]
}
}
],
"restartPolicy" : "Always",
"terminationGracePeriodSeconds" : 30,
"dnsPolicy" : "ClusterFirst",
"securityContext" : {}
}
}
},
"status" : {}
}
Now I know the tutorial uses a Pod kind, and I am using a Deployment kind, but I don't think that is the issue here.

Answer 1

It looks like you are pulling the default redis container. If you check the redis Dokerfiles, for example https://github.com/docker-library/redis/blob/d53b982b387634092c6f11069401679034054ecb/4.0/alpine/Dockerfile, at the bottom, they have:
CMD ["redis-server"]
which will start redis with the default configuration.
Per redis documentation:
https://redis.io/topics/quickstart
under "Starting Redis" section, if you want to provide a different configuration, you would need to start redis with:
redis-server <config file>
Additionally the example in Kubernetes documentation uses a different redis containter:
image: kubernetes/redis
And from the Dokerfile: https://github.com/kubernetes/kubernetes/blob/master/examples/storage/redis/image/Dockerfile, it seems like that one starts Redis with the provided configuration.