WebSphere Liberty operator overview

Operators are extensions to Kubernetes that are customized to automate tasks beyond the initial automation that Kubernetes or Red Hat® OpenShift® provides. The WebSphere® Liberty operator helps you deploy and manage applications on Kubernetes-based clusters.

When you deploy an application with the WebSphere Liberty operator, the operator watches WebSphere Liberty resources and compares the current state of resources to the state of resources that you configured. When a discrepancy exists between the current state of resources and the state that you configured, the operator creates, updates, or deletes Kubernetes resources to return to the state that you configured. These Kubernetes resources might include deployments, services, or routes. Without the WebSphere Liberty operator, you must manually create deployments, services, routes, and other Kubernetes resources, which can involve a time-consuming learning curve. With the WebSphere Liberty operator, you can specify details for your application, including your application image, service port, and whether to expose the application outside the cluster. Then, the WebSphere Liberty operator creates and manages all Kubernetes resources. Now, you manage only a single WebSphere Liberty application resource instead of many resources. In addition, the WebSphere Liberty operator continuously monitors the events that are related to the application in the cluster and takes necessary actions to synchronize data and resources. Because the WebSphere Liberty operator helps you manage Kubernetes resources, you can focus on your application while the WebSphere Liberty operator handles many of the cloud deployment details.

WebSphere Liberty operator capabilities

The WebSphere Liberty operator at a capability level of five has the highest level of enterprise capabilities, including the following capabilities:
High availability that is provided by horizontal auto-scaling
You can configure horizontal auto-scaling to create and delete instances of your application based on resource consumption. This ability to run multiple instances of your application and auto-scale them means that your application is made highly available.
Enhanced deployment management
You can more easily manage applications that are deployed to Kubernetes. For example, in the operator deployment file, you can specify an image stream in the applicationImage field. Then, after you upload a new container tag for a new version of an application, the operator updates the application on a rolling basis.
Automated service binding
The operator automates updates of binding information among applications, meaning that it connects applications and maintains information about whether a particular application produces or consumes a service. With this information, the operator automatically handles Kubernetes-level details, including creating and injecting Kubernetes Secrets, so that your applications can connect to required services without interruption.
Single sign-on (SSO) delegation
You can delegate SSO authentication to external providers. The WebSphere Liberty operator enables easier configuration and management of SSO information for your applications.
Red Hat OpenShift serverless (Knative) integration
You can integrate the operator with Knative. When the operator is integrated with Knative, you deploy your serverless runtime component by using a single toggle. The operator converts all of its generated resources into Knative resources, which allows your pod to automatically scale to zero when it’s idle.
Certificate management integration
The WebSphere Liberty operator takes advantage of the cert-manager tool, if it is installed on the Kubernetes cluster. The cert-manager tool allows the operator to automatically provision Transport Layer Security (TLS) certificates for pods and routes. Certificates are mounted into containers from a Kubernetes Secret so that the certificates are automatically refreshed when they're updated.
Note: The cert-manager operator is not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. For more information, see https://docs.openshift.com/container-platform/4.15/security/cert_manager_operator/index.html.
Day 2 operational capabilities
The WebSphere Liberty operator includes the capability to gather server memory dumps and server traces.

Operator installation and configuration

You can install the WebSphere Liberty operator for use on Kubernetes or Red Hat OpenShift. The WebSphere Liberty operator documentation provides details about configuring the operator, including basic configuration, Custom Resource Definition (CRD) parameters, Open Liberty console logging environment variables, and persistent storage specifications.

Serviceability with the WebSphere Liberty operator

You can enable persistence for your application by specifying only the size of storage and where you want the storage to be mounted. Then, the operator creates and manages the storage claim for you. An advanced mode is available that allows the configuration of extra details of the persistent volume claim. You can also configure and use a single storage for serviceability-related operations, such as gathering server memory dumps and server traces.

Observability with the WebSphere Liberty operator

After you configure the WebSphere Liberty operator, you can integrate Liberty with logging and monitoring tools for observability in the Kubernetes cluster.