Use Operator Lifecycle Manager to Deploy a Kubernetes Operator on Oracle Cloud Native Environment

Introduction

This tutorial assumes you have an existing Kubernetes cluster running on Oracle Cloud Native Environment. This tutorial builds upon the tutorials to deploy Oracle Cloud Native Environment.

Objectives

This tutorial shows you how install the Operator Lifecycle Manager module for Oracle Cloud Native Environment into a Kubernetes cluster, then deploy a Kubernetes operator.

The Operator Lifecycle Manager module installs Operator Lifecycle Manager into a Kubernetes cluster. Operator Lifecycle Manager manages the installation and lifecycle management of Kubernetes operators in a Kubernetes cluster.

This tutorial assumes you have an existing Kubernetes cluster running in Oracle Cloud Native Environment.

Prerequisites

Oracle Cloud Native Environment Release 1.4 deployed which includes a Kubernetes cluster. See the tutorials at

Installing the Operator Lifecycle Manager Module

The Operator Lifecycle Manager is installed into a Kubernetes cluster as an Oracle Cloud Native Environment module.

Edit the deployment configuration file to include the Helm module and the Operator Lifecycle Manager module.

environments:
  - environment-name: myenvironment
...         
    modules:
      - module: kubernetes
        name: mycluster
...
      - module: helm
        name: myhelm
        args:
          helm-kubernetes-module: mycluster
      - module: operator-lifecycle-manager
        name: myolm
        args:
          olm-helm-module: myhelm

The configuration file is abbreviated to show the important information required to install the Operator Lifecycle module. As this module also requires the Helm module, you must supply the information for both.

For the Helm module, set the name of the Kubernetes module with the helm-kubernetes-module option (mycluster in this example).

For the Operator Lifecycle module, set the name of the Helm module with the olm-helm-module option (myhelm in this example).

The filename for this configuration file in this tutorial is myenvironment.yaml.

More information on how to create a configuration file is at Using a Configuration File.

Add the Modules

On the operator node, run the olcnectl module create command with the --config-file option to specify the location of the configuration file. The Platform API Server compares the configuration file with the state of the environment and recognises there are additional modules that should be added to the environment.

olcnectl module create --config-file myenvironment.yaml

Validate the Modules

On the operator node, use the olcnectl module validate command to validate the nodes are configured correctly to deploy the modules. If there are any errors, the commands required to fix the nodes are provided as output of this command.

olcnectl module validate --config-file myenvironment.yaml

Install the Modules

On the operator node, use the olcnectl module install command to deploy the modules to the environment.

olcnectl module install --config-file myenvironment.yaml

The Helm and Operator Lifecycle Manager modules are deployed and the required containers are running in the operator-lifecycle-manager namespace.

Installing the etcd Operator

This example shows you how to create an etcd operator which is pulled from the OperatorHub. This is a very small and basic operator that you can use to validate your installation.

To create an etcd operator:

  1. On a control plane node, download the etcd operator manifest YAML file from the OperatorHub:

    curl --remote-name https://operatorhub.io/install/etcd.yaml

  2. The etcd.yaml operator manifest file contains the information required to create a Namespace, OperatorGroup and Subscription for the etcd operator. At the time of writing, this file contained:

    apiVersion: v1  
kind: Namespace   
metadata:  
 name: my-etcd  
---  
apiVersion: operators.coreos.com/v1  
kind: OperatorGroup  
metadata:  
 name: operatorgroup. 
 namespace: my-etcd  
spec:  
 targetNamespaces:  
 - my-etcd  
---  
apiVersion: operators.coreos.com/v1alpha1  
kind: Subscription  
metadata:  
 name: my-etcd  
 namespace: my-etcd  
spec:  
 channel: singlenamespace-alpha  
 name: etcd  
 source: operatorhubio-catalog  
 sourceNamespace: olm

    Edit the etcd.yaml file to change the sourceNamespace from olm to operator-lifecycle-manager in the Subscription section so that it works properly with Operator Lifecycle Manager. Operator Lifecycle Manager runs in the operator-lifecycle-manager namespace, which is different to the upstream namespace.

    ---
apiVersion: operators.coreos.com/v1alpha1  
kind: Subscription  
metadata:  
 name: my-etcd  
 namespace: my-etcd  
spec:  
 channel: singlenamespace-alpha  
 name: etcd  
 source: operatorhubio-catalog  
 sourceNamespace: operator-lifecycle-manager

  3. Use the kubectl apply command to deploy the etcd operator.

    kubectl apply -f etcd.yaml

    The output should look similar to:

    namespace/my-etcd created
operatorgroup.operators.coreos.com/operatorgroup created
subscription.operators.coreos.com/my-etcd created

    The operator is deployed into the namespace set in the operator manifest file, which in this example is my-etcd.

  4. You can see the operator pods are running using:

    kubectl get pods -n my-etcd

    The output should look similar to:

    NAME                             READY   STATUS    RESTARTS   AGE
etcd-operator-75fb7df8b5-42k7b   3/3     Running   0          5m45s

  5. To remove the operator, use the kubectl delete command:

    kubectl delete -f etcd.yaml

For More Information

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