Creating and adding Zowe extension containers

Zowe extensions such as services and plug-ins that use Zowe component packaging can be used within a Zowe container environment. To do this, the extension component must be delivered as a container image that is compatible with Zowe containers. Following Zowe's container conformance criteria is recommended to make compatibility easy to accomplish and understand.

You can add extension component containers to a Zowe container environment the same way as Zowe's own components.

1. Build and publish a component image to a registry.
2. Define a deployment object
3. Start the component from the deployment.

1. Build and publish a component image to a registry

An extension component must have a container image to run in a Zowe container environment.

You can use a Dockerfile to create such images, and can follow some examples of how the Zowe core components are built. The core components define component Dockerfiles and use GitHub Actions to build images. For example, explorer-jes component has a Dockerfile defined at https://github.com/zowe/explorer-jes/blob/master/container/Dockerfile and defines a GitHub Actions workflow https://github.com/zowe/explorer-jes/blob/master/.github/workflows/explorer-jes-images.yml to build the image.

The following are Actions used by the core components to build conformant images. They may not be completely reusable for extenders, but are provided as an example.

• zowe-actions/shared-actions/docker-prepare will prepare required environment variables used by following steps.
• zowe-actions/shared-actions/docker-build-local can build docker image directory on GitHub Actions virtual machine. By default it will be ubuntu-latest. This action can be used to build image for amd64 CPU architecture.
• zowe-actions/shared-actions/docker-build-zlinux can build docker image on a Linux on Z virtual machine. This is useful if you want to build image for s390x CPU architecture.
• zowe-actions/shared-actions/docker-manifest can collect all related images and define them as docker manifests. This is useful for end user to automatically pull the correct image based on cluster node CPU architecture, and also pull images based on popular tags like latest and latest-ubuntu.

Once a component image is built, you must publish it to a container registry before it can be added to the Zowe container environment.

2. Define Deployment object

To start your component in Kubernetes, you need to define a Deployment object. To define Deployment for your component, you can copy from samples/sample-deployment.yaml and modify all occurrences of the following variables:

• <my-component-name>: this is your component name. For example, sample-node-api.
• <my-component-image>: this is your component image described in the above section. For example, zowe-docker-release.jfrog.io/ompzowe/sample-node-api:latest-ubuntu.
• <my-component-port>: this is the port of your service. For example, 8080.

Continue to customize the specification to fit in your component requirements:

• spec.replicas: defines how many pods you want to start for your component,
• spec.template.spec.containers[0].resources: defines the memory and CPU resource required to start the container,
• metadata.annotations, spec.template.spec.volumes and spec.template.spec.securityContext and so on.

3. Start your component

After you define your component Deployment object, you can run kubectl apply -f /path/to/your/component-deployment.yaml to apply it to Kubernetes cluster that runs Zowe.

Now you can follow common Kubernetes practice to manage your component workload.