Installation | Kurrent Docs
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Installation

This section covers the various aspects of installing the Operator.

The Operator supports installation via Helm and via the Operator Lifecycle Manager (OLM). OLM is the recommended way to install on Red Hat OpenShift clusters, where OLM is installed by default.

Important

The Operator is an Enterprise-only feature, please contact us for more information.

Install Using Helm

Prerequisites

  • A Kubernetes cluster running any non-EOL version of Kubernetes.
  • Permission to create resources, deploy the Operator and install CRDs in the target cluster.
  • The following CLI tools installed, on your shell’s $PATH, with $KUBECONFIG pointing to your cluster:
  • A valid Operator license. Please contact us for more information.

Configure Helm Repository

Add the Kurrent Helm repository to your local environment:

helm repo add kurrent-latest \
  'https://packages.kurrent.io/basic/kurrent-latest/helm/charts/'

Basic Installation

The most basic installation will:

  • install necessary CRDs
  • run the Operator with a ClusterRole
  • configure the Operator to watch all namespaces

To install in this way, run:

helm install kurrentdb-operator kurrent-latest/kurrentdb-operator \
  --version 1.4.3 \
  --create-namespace \
  --namespace kurrent-system \
  --set-file operator.license.key=/path/to/license.key \
  --set-file operator.license.file=/path/to/license.lic

This command:

  • Creates kurrent-system and deploys the Operator into it.
  • Deploys CRDs.
  • Applies the Operator license.
  • Populates a new Helm release called kurrentdb-operator in the kurrent namespace.

Expected Output:

NAME: kurrentdb-operator
LAST DEPLOYED: Thu Mar 20 14:51:42 2025
NAMESPACE: kurrent-system
STATUS: deployed
REVISION: 1
TEST SUITE: None

Additional customizations are described in the following sections.

Option: Targeting Specific Namespaces

The Operator may be installed to only control resources in specific namespaces. When installed in this way, it uses a Role in each target namespace rather than a ClusterRole.

For example, to configure the Operator to control resources in namespaces foo and bar, add a flag like --set operator.namespaces='{foo,bar}' to the installation steps described in Basic Installation.

Important

Make sure the namespaces listed as part of the operator.namespaces parameter already exist before running the Helm installation.

Note that there is no requirement that namespace used for the Helm installation overlap with the namespaces controlled by the Operator.

Option: Manual CRD Installation

Some prefer to deploy CRDs manually, rather than through Helm. In this case, you must manually install the CRDs before the Helm installation (and again with each upgrade):

# Download the kurrentdb-operator Helm chart
helm pull kurrent-latest/kurrentdb-operator --version 1.4.3 --untar

# Install the CRDs
kubectl apply -f kurrentdb-operator/templates/crds

Expected Output:

customresourcedefinition.apiextensions.k8s.io/kurrentdbs.kubernetes.kurrent.io created
customresourcedefinition.apiextensions.k8s.io/kurrentdbbackups.kubernetes.kurrent.io created
customresourcedefinition.apiextensions.k8s.io/kurrentdbbackupschedules.kubernetes.kurrent.io created

Then, follow the installation steps described in Basic Installation with the additional flag --set crds.enabled=false.

Due to the extra steps at both installation and upgrade, we recommend letting the Helm chart automatically manage your CRDs.

Caution

If you set the value of crds.keep to false (the default is true), helm upgrades and rollbacks can result in data loss. If crds.keep is false and crds.enabled transitions from true to false during an upgrade or rollback, the CRDs will be removed from the cluster, deleting all KurrentDBs and KurrentDBBackups and their associated child resources, including the PVCs and VolumeSnapshots containing your data!

Upgrading A Helm Installation

The Operator can be upgraded using the following helm commands:

helm repo update kurrent-latest
helm upgrade kurrentdb-operator kurrent-latest/kurrentdb-operator \
  --namespace kurrent \
  --version {version} \
  --reset-then-reuse-values

Here's what these commands do:

  • Refresh the local Helm repository index
  • Locate an existing operator installation in namespace kurrent
  • Select the target upgrade version {version} e.g. 1.4.3
  • Perform the upgrade, preserving values that were set during installation

Install Using OLM

Prerequisites

  • An OpenShift cluster (version 4.17 or newer), or Kubernetes with OLM installed.
  • Permission to create resources, deploy the Operator and install CRDs in the target cluster.
  • oc (or kubectl) installed, on installed, on your shell’s $PATH, with $KUBECONFIG pointing to your cluster
  • A valid Operator license. Please contact us for more information.

Configure Namespaces

Choose the namespace into which you will install your operator, and also the namespaces you want your operator to control. Create the namespaces now:

# a namespace into which we will install the operator
oc create namespace kurrent-system

# namespaces we want the operator to control
oc create namespace foo bar

Create A Secret

The Operator requires a Secret in its namespace containing a valid license. For OLM installations, the name of the secret must be kurrentdb-operator.

oc create secret generic -n kurrent-system kurrentdb-operator \
    --from-file=licenseKey=/path/to/license.key \
    --from-file=licenseFile=/path/to/license.lic

Create A CatalogSource

A CatalogSource is the resource that tells OLM where to look for available operator versions.

oc apply -f - << EOF
apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  name: kurrentdb-operator
  namespace: olm
spec:
  sourceType: grpc
  image: docker.kurrent.io/kurrent-latest/kurrentdb-operator-catalog:latest
  displayName: KurrentDB Operator
  publisher: "Kurrent, Inc"
  grpcPodConfig:
    securityContextConfig: restricted
EOF

Create An OperatorGroup

An OperatorGroup is the resource that tells OLM which namespaces an operator should target.

oc apply -f - <<EOF
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: kurrentdb-operator
  namespace: kurrent-system
spec:
  upgradeStrategy: Default
  targetNamespaces:
  - foo
  - bar
EOF

If you wish for the Operator to target all namespaces, omit the targetNamespaces field entirely.

Create A Subscription

A Subscription is the resource that asks OLM to install a particular operator into a namespace. Operators installed by the Subscription will target namespaces described by the OperatorGroup in that namespace.

oc apply -f - <<EOF
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: kurrentdb-operator
  namespace: kurrent-system
spec:
  channel: fast-v1
  installPlanApproval: Automatic
  name: kurrentdb-operator
  source: kurrentdb-operator
  sourceNamespace: default
  startingCSV: kurrentdb-operator.v1.4.3
EOF

Now with the CatalogSource, OperatorGroup, and Subscription created, the Operator will be installed automatically by OLM, though it may take a couple minutes for the whole process to complete.

Deployment Validation

Whether you installed using Helm or OLM, you can validate that the installation is working with kubectl (or using oc on an OpenShift cluster).

Check that the Deployment running the operator looks healthy:

kubectl get -n kurrent-system deployments

You should see 1/1 pods ready in the kurrentdb-operator Deployment:

NAME                 READY   UP-TO-DATE   AVAILABLE   AGE
kurrentdb-operator   1/1     1            1           10m

If not, check for error events in the Operator namespace for errors like image pull failures, scheduling problems, or operator crashes:

kubectl events -n kurrent-system

If the Operator is starting successfully but then crashing, check the logs for issues like license key or file issues:

kubectl logs -n kurrent-system deployments/kurrentdb-operator

If you are stuck, don't hesitate to reach out to support.

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