Undermoon Operator

Kubernetes operator for easy Redis Cluster management based on undermoon using operator-sdk.

Usage

Run the Operator

Run the undermoon-operator: Note that you can change the name my-undermoon-operator.

helm install my-undermoon-operator helm/undermoon-operator

Create an Undermoon Cluster

Create an undermoon cluster by installing helm charts package:

helm install \
    --set 'cluster.clusterName=my-cluster-name' \
    --set 'cluster.chunkNumber=1' \
    --set 'cluster.maxMemory=2048' \
    --set 'cluster.port=5299' \
    my-cluster \
    -n my-namespace \
    helm/undermoon-cluster

Fields here:

• clusterName: Name of the cluster. Should be less than 30 bytes. This can't be modifed.
• chunkNumber: Used to specify the node number of the cluster. One chunk always consists of 2 masters and 2 replicas. Modify this to scale the cluster.
• maxMemory: Specifies the maxmemory config for each Redis node in MBs. Modify this will trigger rolling upgrade.
• port: The service port your redis clients connect to. This can't be modifed.

Then you can access the service through my-cluster:5299 inside the Kubernetes cluster:

# This can only be run inside the Kubernetes cluster.
redis-cli -h my-cluster.my-namespace.svc.cluster.local -p 5299 -c get mykey

Scale the Cluster

kubectl edit undermoon/my-cluster
# Change the `chunkNumber`, save, and exit.

Then the cluster will automatically scale the cluster.

Using undermoon-scheduler

By default, undermoon does not guarantee master and replica redis instances in the same shard are not in the same node. We need to use undermoon-scheduler based on scheduler framework to achieve that.

This will install undermoon-scheduler as a second scheduler. You may want to replace the default scheduler instead. See the docs from scheduler-plugins for more details.

helm install example-scheduler -n my-namespace helm/undermoon-scheduler

Then specify the schedulerName when installing undermoon-cluster:

helm install \
    --set 'cluster.clusterName=my-cluster-name' \
    --set 'cluster.chunkNumber=1' \
    --set 'cluster.maxMemory=2048' \
    --set 'cluster.port=5299' \
    --set "schedulerName=undermoon-scheduler" \
    my-cluster \
    -n my-namespace \
    helm/undermoon-cluster

Docs

• Development