Redis sentinel for k8s

Helm 3 charts for Redis Sentinel and kubernetes.

The main goal is to run redis sentinel with the ability to connect from outside the kubernetes cluster

Other sentinel charts do not support that (e.g. issue for bitnami bitnami/charts#3524)

Internally it uses node IPs (not k8s network) for communication between redis nodes and sentinel

Deploy

export NAMESPACE=test-namespace
export RELEASE_NAME=release

helm upgrade -i --namespace ${NAMESPACE} \
 --set "redis.redisHostPort=36379" \
 --set "redis.sentinelHostPort=26379" \
 --atomic \
 --debug \
 --wait \
 $RELEASE_NAME \
 ./redis-ha

in that example, redis will use port 36379 and sentinel will use port 26379 (hostPort in k8s)

Check

You can check that sentinel will return external IP of node e.g. execute inside container

redis-cli -h 127.0.0.1 -p 26379 --raw sentinel master mycluster | grep -A1 "ip" | grep -v "ip"

will return ip like that 192.168.10.45

Node configuration

It's recommended to follow redis recommendations for the best performance

sysctl -w vm.overcommit_memory=1
sysctl -w net.core.somaxconn=1024
echo -n "never" > /tph/enabled

Limitations

Because it uses hostPort, you should control on which nodes redis can be scheduled (to avoid changes in node external address). The best way is to use LocalVolume