openshift-docs/operators/operator_sdk/java/osdk-java-tutorial.adoc

:_mod-docs-content-type: ASSEMBLY
[id="osdk-java-tutorial"]
= Operator SDK tutorial for Java-based Operators
include::_attributes/common-attributes.adoc[]
:context: osdk-java-tutorial
:FeatureName: Java-based Operator SDK
include::snippets/technology-preview.adoc[]

// This assembly is not currrently included in the OSD and ROSA distros, because it is Tech Preview. However, some conditionalization has been added for OSD and ROSA so that the content will be applicable to those distros once this feature is GA and included in the OSD and ROSA docs.

toc::[]

Operator developers can take advantage of Java programming language support in the Operator SDK to build an example Java-based Operator for Memcached, a distributed key-value store, and manage its lifecycle.

include::snippets/osdk-deprecation.adoc[]

This process is accomplished using two centerpieces of the Operator Framework:

Operator SDK:: The `operator-sdk` CLI tool and `java-operator-sdk` library API

Operator Lifecycle Manager (OLM):: Installation, upgrade, and role-based access control (RBAC) of Operators on a cluster

ifndef::openshift-dedicated,openshift-rosa,openshift-rosa-hcp[]
[NOTE]
====
This tutorial goes into greater detail than xref:../../../operators/operator_sdk/java/osdk-java-quickstart.adoc#osdk-java-quickstart[Getting started with Operator SDK for Java-based Operators].
====
endif::openshift-dedicated,openshift-rosa,openshift-rosa-hcp[]

// The "Getting started" quickstarts require cluster-admin and are therefore only available in OCP.
ifdef::openshift-dedicated,openshift-rosa,openshift-rosa-hcp[]
[NOTE]
====
This tutorial goes into greater detail than link:https://access.redhat.com/documentation/en-us/openshift_container_platform/4.13/html-single/operators/index#osdk-java-quickstart[Getting started with Operator SDK for Java-based Operators] in the OpenShift Container Platform documentation.
====
endif::openshift-dedicated,openshift-rosa,openshift-rosa-hcp[]

include::modules/osdk-common-prereqs.adoc[leveloffset=+1]

[role="_additional-resources"]
.Additional resources
* xref:../../../operators/operator_sdk/osdk-installing-cli.adoc#osdk-installing-cli[Installing the Operator SDK CLI]
* xref:../../../cli_reference/openshift_cli/getting-started-cli.adoc#getting-started-cli[Getting started with the OpenShift CLI]

include::modules/osdk-create-project.adoc[leveloffset=+1]
include::modules/osdk-project-file.adoc[leveloffset=+2]

include::modules/osdk-java-create-api-controller.adoc[leveloffset=+1]
include::modules/osdk-java-define-api.adoc[leveloffset=+2]
include::modules/osdk-java-generate-crd.adoc[leveloffset=+2]
include::modules/osdk-java-create-cr.adoc[leveloffset=+2]

include::modules/osdk-java-implement-controller.adoc[leveloffset=+1]

The next subsections explain how the controller in the example implementation watches resources and how the reconcile loop is triggered. You can skip these subsections to go directly to xref:../../../operators/operator_sdk/java/osdk-java-tutorial.adoc#osdk-run-operator_osdk-java-tutorial[Running the Operator].

include::modules/osdk-java-controller-reconcile-loop.adoc[leveloffset=+2]
include::modules/osdk-java-controller-labels-memcached.adoc[leveloffset=+2]
include::modules/osdk-java-controller-memcached-deployment.adoc[leveloffset=+2]

include::modules/osdk-run-operator.adoc[leveloffset=+1]

ifdef::openshift-dedicated,openshift-rosa,openshift-rosa-hcp[]
[role="_additional-resources"]
.Additional resources
* link:https://access.redhat.com/documentation/en-us/openshift_container_platform/4.13/html-single/operators/index#osdk-run-locally_osdk-java-tutorial[Running locally outside the cluster] (OpenShift Container Platform documentation)
* link:https://access.redhat.com/documentation/en-us/openshift_container_platform/4.13/html-single/operators/index#osdk-run-deployment_osdk-java-tutorial[Running as a deployment on the cluster] (OpenShift Container Platform documentation)
endif::openshift-dedicated,openshift-rosa,openshift-rosa-hcp[]

// In OSD/ROSA, the only applicable option for running the Operator is to bundle and deploy with OLM.
ifndef::openshift-dedicated,openshift-rosa,openshift-rosa-hcp[]
include::modules/osdk-run-locally.adoc[leveloffset=+2]
include::modules/osdk-run-deployment.adoc[leveloffset=+2]
endif::openshift-dedicated,openshift-rosa,openshift-rosa-hcp[]

[id="osdk-bundle-deploy-olm_{context}"]
=== Bundling an Operator and deploying with Operator Lifecycle Manager

include::modules/osdk-bundle-operator.adoc[leveloffset=+3]
include::modules/osdk-deploy-olm.adoc[leveloffset=+3]

[role="_additional-resources"]
[id="additional-resources_osdk-java-tutorial"]
== Additional resources

* See xref:../../../operators/operator_sdk/java/osdk-java-project-layout.adoc#osdk-java-project-layout[Project layout for Java-based Operators] to learn about the directory structures created by the Operator SDK.
* If a xref:../../../networking/enable-cluster-wide-proxy.adoc#enable-cluster-wide-proxy[cluster-wide egress proxy is configured], cluster administrators can xref:../../../operators/admin/olm-configuring-proxy-support.adoc#olm-configuring-proxy-support[override the proxy settings or inject a custom CA certificate] for specific Operators running on Operator Lifecycle Manager (OLM).