Installation and upgrade

Contents

Introduction

This installation guide describes how to configure, install (deploy), update, upgrade, and uninstall an instance of the WebLogic Kubernetes Operator. A single instance is capable of managing multiple domains in multiple namespaces, depending on how it is configured. A Kubernetes cluster can host multiple operators, but no more than one per namespace.

Install the operator

Before installing the operator, ensure that each of its prerequisite requirements is met. See Prepare for installation.

By default, installing the operator also configures a deployment and supporting resources for the conversion webhook and deploys the conversion webhook. The conversion webhook deployment is required for operator version 4.x. When a conversion webhook is already installed, skip the conversion webhook installation by setting the Helm configuration value operatorOnly to true in the helm install command. For more details, see install the conversion webhook.

After meeting the prerequisite requirements, install the operator using the helm install command with the operator Helm chart according to the following instructions.

Minimally you should specify:

  • A Helm “release” name for the operator
  • The Helm chart location
  • The operator namespace
  • The platform (if required)
  • The namespace selection settings

A typical Helm release name is weblogic-operator. The operator samples and documentation often use sample-weblogic-operator.

You can override default configuration values in the Helm chart by doing one of the following:

  • Creating a custom YAML file containing the values to be overridden, and specifying the --value option on the Helm command line.
  • Overriding individual values directly on the Helm command line, using the --set option.

You supply the --namespace argument from the helm install command line to specify the namespace in which the operator will be installed. If not specified, then it defaults to default. If the namespace does not already exist, then Helm will automatically create it (and Kubernetes will create a default service account in the new namespace), but note that Helm will not remove the namespace or service account when the release is uninstalled. If the namespace already exists, then Helm will use it. These are standard Helm behaviors.

Similarly, you may override the default serviceAccount configuration value to specify a service account in the operator’s namespace that the operator will use. For common use cases, the namespace default service account is sufficient. If you want to use a different service account (recommended), then you must create the operator’s namespace and the service account before installing the operator Helm chart (for instructions, see Prepare for installation).

For example, using Helm 3.x, with the following settings:

Setting Value and Notes
Helm release name sample-weblogic-operator (you may choose any name)
Helm chart repo URL https://oracle.github.io/weblogic-kubernetes-operator/charts
Helm chart repo name weblogic-operator
namespace sample-weblogic-operator-ns 
$ kubectl create namespace sample-weblogic-operator-ns

Access the operator Helm chart using this format: helm repo add <helm-chart-repo-name> <helm-chart-repo-url>. Each version of the Helm chart defaults to using an operator image from the matching version.

$ helm repo add weblogic-operator https://oracle.github.io/weblogic-kubernetes-operator/charts --force-update  

  • To get information about the operator Helm chart, use the helm show command with this format: helm show <helm-chart-repo-name>/weblogic-operator. For example, with an operator Helm chart where the repository is named weblogic-operator:

    $ helm show chart weblogic-operator/weblogic-operator
$ helm show values weblogic-operator/weblogic-operator

  • To list the versions of the operator that you can install from the Helm chart repository:

    $ helm search repo weblogic-operator/weblogic-operator --versions

  • For a specified version of the Helm chart and operator, use the --version <value> option with helm install to choose the version that you want, with the latest value being the default.

Install the operator using this format: helm install <helm-release-name> <helm-chart-repo-name>/weblogic-operator ...

$ helm install sample-weblogic-operator \
  weblogic-operator/weblogic-operator \
  --namespace sample-weblogic-operator-ns \
  --wait

This creates a Helm release named sample-weblogic-operator in the sample-weblogic-operator-ns namespace, configures a deployment and supporting resources for the operator, and deploys the operator.

You can verify the operator installation by examining the output from the helm install command.

To check if the operator is deployed and running, see Troubleshooting.

Notes:

  • In this example, you have not set the kubernetesPlatform, but this may be required for your environment. See Determine the platform setting.
  • For more information on specifying the registry credentials when the operator image is stored in a private registry, see Customizing operator image name, pull secret, and private registry.
  • Do not include a backslash (\) before the equals sign (=) in a domain namespace label selector when specifying the selector in a YAML file. A backslash (\) is only required when specifying the selector on the command line using --set, as shown in the previous example.

Install the WebLogic domain resource conversion webhook

By default, the WebLogic domain resource conversion webhook is automatically installed the first time an operator is installed in a cluster and removed the first time an operator is uninstalled.

Note: If you are using multiple operators, or want to be able to create or alter domains even when no operators are running, then you will need to fine tune this life cycle. For conversion webhook installation details, see Install the conversion webhook.

Set up domain namespaces

To configure or alter the namespaces that an operator will check for domain resources, see Namespace management.

Update a running operator

You can update the settings on a running operator by using the helm upgrade command.

In most use cases, you should specify --reuse-values on the helm upgrade command line to ensure that the operator continues to use the values that you have already specified (otherwise the operator will revert to using the default for all values).

Example updates:

Upgrade the operator

You can upgrade a 3.x operator while the operator’s domain resources are deployed and running. The following instructions will be applicable to upgrade operators as additional versions are released.

When upgrading the operator:

  • Use helm repo add to supply a new version of the Helm chart.
  • Use the helm upgrade command with the --reuse-values parameter.
  • Supply a new image value.

The rationale for supplying a new image value is because, even with a new version of the Helm chart, --reuse-values will retain the previous image value from when it was installed. To upgrade, you must override the image value to use the new operator image version.

NOTE: When upgrading a 3.x operator to 4.x, note that the default value of domainNamespaceSelectionStrategy changed from List to LabelSelector, so you need to label the namespaces that the operator is supposed to watch, rather than just providing the list of namespaces. For detailed information, see Namespace management.

For example:

$ helm repo add weblogic-operator https://oracle.github.io/weblogic-kubernetes-operator/charts --force-update
$ helm upgrade sample-weblogic-operator \
  weblogic-operator/weblogic-operator \
  --reuse-values \
  --set image=ghcr.io/oracle/weblogic-kubernetes-operator:4.0.9
 \
  --namespace sample-weblogic-operator-ns \
  --wait

Upgrading a 3.x operator will not automatically roll any running WebLogic Server instances created by the original operator. It is not necessary and such instances will continue to run without interruption during the upgrade.

When you upgrade a 3.x operator to 4.0, it will also create a WebLogic Domain resource conversion webhook deployment and its associated resources in the same namespace. If the conversion webhook deployment already exists in some other namespace, then a new conversion webhook deployment is not created. The webhook automatically and transparently upgrades the existing Domains from the 3.x schema to the 4.0 schema. For more information, see WebLogic Domain resource conversion webhook.

Uninstall the operator

If you uninstall an operator, then any domains that it is managing will continue running; however, any changes to a domain resource that was managed by the operator will not be detected or automatically handled, and, if you want to clean up such a domain, then you will need to manually delete all of the domain’s resources (domain, pods, services, and such).

The helm uninstall command is used to remove an operator release and its associated resources from the Kubernetes cluster. The Helm release name and namespace used with the helm uninstall command must be the same release name used with the helm install command (see Install the operator).

For example, assuming the Helm release name is sample-weblogic-operator and the operator namespace is sample-weblogic-operator-ns:

$ helm uninstall sample-weblogic-operator -n sample-weblogic-operator-ns

If the operator’s namespace or service account did not exist before the Helm chart was installed, then Helm will create them during helm install; however, helm uninstall will not remove them.

After removing the operator deployment, you should also remove the Domain and Cluster custom resource definitions (CRD) if they are no longer needed:

$ kubectl delete customresourcedefinition domains.weblogic.oracle
$ kubectl delete customresourcedefinition clusters.weblogic.oracle

Note that the custom resource definitions are shared. Do not delete them if there are other operators in the same cluster or you have running domain resources.

Beginning with operator version 4.0, uninstalling an operator also removes the conversion webhook deployment and its associated resources by default. Therefore, if you have multiple operators running, then, by default, an uninstall of one operator will affect the other operators. The uninstall will not delete the conversion definition in the domain CRD so you will be unable to create domains using weblogic.oracle/v8 schema. If you want to prevent the uninstall of an operator
from having these side effects, then use one of the following two options:

  • Install the conversion webhook in a separate namespace using webhookOnly=true Helm configuration value.
  • Use the preserveWebhook=true Helm configuration value during operator installation with the helm install command.

For more information, see uninstall the conversion webhook for the conversion webhook uninstallation details.

Installation sample

For an example of installing the operator, setting the namespace that it monitors, deploying a domain resource to its monitored namespace, and uninstalling the operator, see the Quick Start.