$ mkdir memcached-operator
Java-based Operator SDK is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.
To demonstrate the basics of setting up and running a Java-based Operator using tools and libraries provided by the Operator SDK, Operator developers can build an example Java-based Operator for Memcached, a distributed key-value store, and deploy it to a cluster.
Operator SDK CLI installed
OpenShift CLI (
oc) v4.12+ installed
Logged into an OKD 4.12 cluster with
oc with an account that has
To allow the cluster to pull the image, the repository where you push your image must be set as public, or you must configure an image pull secret
You can build and deploy a simple Java-based Operator for Memcached by using the Operator SDK.
Create a project.
Create your project directory:
$ mkdir memcached-operator
Change into the project directory:
$ cd memcached-operator
operator-sdk init command
to initialize the project:
$ operator-sdk init \ --plugins=quarkus \ --domain=example.com \ --project-name=memcached-operator
Create an API.
Create a simple Memcached API:
$ operator-sdk create api \ --plugins quarkus \ --group cache \ --version v1 \ --kind Memcached
Build and push the Operator image.
Use the default
Makefile targets to build and push your Operator. Set
IMG with a pull spec for your image that uses a registry you can push to:
$ make docker-build docker-push IMG=<registry>/<user>/<image_name>:<tag>
Run the Operator.
Install the CRD:
$ make install
Deploy the project to the cluster. Set
IMG to the image that you pushed:
$ make deploy IMG=<registry>/<user>/<image_name>:<tag>
Create a sample custom resource (CR).
Create a sample CR:
$ oc apply -f config/samples/cache_v1_memcached.yaml \ -n memcached-operator-system
Watch for the CR to reconcile the Operator:
$ oc logs deployment.apps/memcached-operator-controller-manager \ -c manager \ -n memcached-operator-system
Delete a CR
Delete a CR by running the following command:
$ oc delete -f config/samples/demo_v1_nginx.yaml -n nginx-operator-system
Run the following command to clean up the resources that have been created as part of this procedure:
$ make undeploy
See Operator SDK tutorial for Java-based Operators for a more in-depth walkthrough on building a Java-based Operator.