Skip to main content

Install Dragonfly Kubernetes Operator

Dragonfly Operator is a Kubernetes operator used to deploy and manage Dragonfly instances in your Kubernetes clusters.

The main features include:

  • Automatic Failover
  • Scaling Horizontally and Vertically (with Custom Rollout Strategy)
  • Custom Configuration Options
  • Authentication and Server TLS
  • Snapshots to Persistent Volume Claims (PVCs) and S3-Compatible Cloud Storage
  • Monitoring with Prometheus and Grafana

Prerequisites​

  • A working Kubernetes cluster (tested with Kubernetes 1.19+)
  • kubectl installed and configured to connect to your cluster

Installation​

Make sure your Kubernetes cluster is up and running. To install Dragonfly Operator, run the following command:

# Install the Dragonfly Kubernetes Operator.
kubectl apply -f https://raw.githubusercontent.com/dragonflydb/dragonfly-operator/main/manifests/dragonfly-operator.yaml

By default, the operator will be installed in the dragonfly-operator-system namespace.

Usage​

Create a Dragonfly instance with replicas​

To set up a sample Dragonfly topology with a primary (master) and optional replicas (slaves), run the following command:

kubectl apply -f https://raw.githubusercontent.com/dragonflydb/dragonfly-operator/main/config/samples/v1alpha1_dragonfly.yaml

Important Note: In the Dragonfly Kubernetes Operator, the replicas configuration adheres to Kubernetes' standard semantics, specifying the number of instances to run. However, since Dragonfly is a stateful data store, the interpretation differs, as it relates to a high-availability setup. For example:

  • Setting replicas=1 creates 1 primary instance of Dragonfly only.
  • Setting replicas=2 creates 1 primary and 1 replica of Dragonfly.
  • Setting replicas=3 creates 1 primary and 2 replicas of Dragonfly, and so on.
  • There is always only 1 primary Dragonfly instance.

To check the status of the instance, run the following command:

kubectl describe dragonflies.dragonflydb.io dragonfly-sample

Connect to the primary instance of the service at: <dragonfly-name>.<namespace>.svc.cluster.local. As pods are added or removed, the service automatically updates to point to the new primary.

Connect with redis-cli​

To connect to the instance using redis-cli, run the following command:

kubectl run -it --rm --restart=Never redis-cli --image=redis:7.0.10 -- redis-cli -h dragonfly-sample.default

The command creates a temporary pod that runs the redis-cli and connects to the instance. For example, to set and retrieve a key, run the following commands:

# If you don't see a command prompt, try pressing enter.
dragonfly-sample.default:6379$> GET my_key
(nil)

dragonfly-sample.default:6379$> SET my_key my_val
OK

dragonfly-sample.default:6379$> GET my_key
"my_val"

dragonfly-sample.default:6379$> QUIT
OK

Change the number of replica instances​

To change the number of replica instances, edit the spec.replicas field. For example, to scale up to 1 primary with 4 replica instances of Dragonfly, run the following command:

kubectl patch dragonfly dragonfly-sample --type merge -p '{"spec":{"replicas":5}}'

Pass custom Dragonfly arguments​

To pass custom arguments (server configuration flags) to Dragonfly, edit the spec.args field. For example, to configure Dragonfly to require a password, run the following command:

kubectl patch dragonfly dragonfly-sample --type merge -p '{"spec":{"args":["--requirepass=supersecret"]}}'

Vertically scale the instances​

To vertically scale the instances, edit the spec.resources field. For example, to increase the CPU requests to 2 cores, run the following command:

kubectl patch dragonfly dragonfly-sample --type merge -p '{"spec":{"resources":{"requests":{"cpu":"2"}}}}'

To understand how to configure high availability, please refer to the related section.