Install Dragonfly Kubernetes Operator
Dragonfly Operator is a Kubernetes operator used to deploy and manage Dragonfly instances inside your Kubernetes clusters. Main features include:
- Automatic failover
- Scaling Horizontally and Vertically
- Custom configuration options
Currently, Dragonfly Operator is in Alpha. You can find more information about Dragonfly in the official documentation.
Prerequisites
- Working Kubernetes cluster (tested with Kubernetes 1.19+)
- kubectl installed and configured to connect to your cluster
Installation
Make sure to have your Kubernetes cluster up and running. Dragonfly Operator can be installed by running
# Install CRDs
kubectl apply -f https://raw.githubusercontent.com/dragonflydb/dragonfly-operator/main/manifests/crd.yaml
# Install the 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
Creating a Dragonfly instance
To create a sample Dragonfly instance, you can run the following command:
kubectl apply -f https://raw.githubusercontent.com/dragonflydb/dragonfly-operator/main/config/samples/v1alpha1_dragonfly.yaml
This will create a Dragonfly instance with 3 replicas. You can check the status of the instance by running
kubectl describe dragonflies.dragonflydb.io dragonfly-sample
A service of the form <dragonfly-name>.<namespace>.svc.cluster.local
will be created, that selects the master instance. You can use this service to connect to the cluster. As pods are added/removed, the service will automatically update to point to the new master.
Connecting with redis-cli
To connect to the cluster using redis-cli
, you can run:
kubectl run -it --rm --restart=Never redis-cli --image=redis:7.0.10 -- redis-cli -h dragonfly-sample.default
This will create a temporary pod that runs redis-cli
and connects to the cluster. After pressing shift + R
, You can then run Redis commands as
usual. For example, to set a key and get it back, you can run
If you don't see a command prompt, try pressing enter.
dragonfly-sample.default:6379> GET 1
(nil)
dragonfly-sample.default:6379> SET 1 2
OK
dragonfly-sample.default:6379> GET 1
"2"
dragonfly-sample.default:6379> exit
pod "redis-cli" deleted
Scaling up/down the number of replicas
To scale up/down the number of replicas, you can edit the spec.replicas
field in the Dragonfly instance. For example, to scale up to 5 replicas, you can run
kubectl patch dragonfly dragonfly-sample --type merge -p '{"spec":{"replicas":5}}'
Passing Custom Dragonfly Arguments
To pass custom arguments to Dragonfly, you can edit the spec.args
field in the Dragonfly instance. For example, to have
Dragonfly require a password, you can run
kubectl patch dragonfly dragonfly-sample --type merge -p '{"spec":{"args":["--requirepass=supersecret"]}}'
Vertically scaling the instance
To vertically scale the instance, you can edit the spec.resources
field in the Dragonfly instance. For example, to increase the CPU limit to 2 cores, you can run
kubectl patch dragonfly dragonfly-sample --type merge -p '{"spec":{"resources":{"requests":{"memory":"1Gi"},"limits":{"memory":"2Gi"}}}}'