Components of IBM z/OS Container Platform

IBM® z/OS® Container Platform (zOSCP) is made up of various open source technologies that have been ported to IBM z/OS as well as new technologies enabling z/OS to interact with these open source technologies. Its core components can be grouped broadly into three sets. One set supports orchestration of the Kubernetes cluster, including managing z/OS systems in the cluster. Another set makes up the container runtime and another set is tools for working with container images. In addition, container images are provided for use with zOSCP.

Figure 1 illustrates the components of zOSCP and each one is described in the surrounding text. For help with container terminology, see Terms to understand about containers.

What are the container runtime components?

The following components create and run containers on z/OS. For more information, see What are the container runtime components in IBM z/OS Container Platform?

Component	Description
IBM z/OS for conmon (conmon)	conmon is a monitoring program and communication tool between a container manager (for example, Podman) and an OCI runtime (runC) for a single container. No users interact directly with conmon.
Container Network Interface for IBM z/OS (IBM z/OS CNI)	The IBM z/OS CNI plug-ins provide a network fabric for the containers to communicate with each other across the cluster and for external communications.
IBM z/OS for runC (runC)	An open source container runtime with a low-level CLI for running containers that are built to OCI standards with the Open Container Initiative (OCI) specification.

What are the Kubernetes components?

The following components enable Kubernetes to orchestrate containers on z/OS.

Component	Description
Control plane and IBM z/OS Control Plane Appliance (zCPA)	The Kubernetes control plane manages the worker nodes and the resources in the cluster. A control plane runs on one or more control plane nodes. The IBM z/OS Control Plane Appliance (zCPA) runs within a z/OS address space and enables one or more z/OS systems to participate as control plane nodes in a Kubernetes cluster. In zOSCP, each control plane node operates in a zCPA.
IBM z/OS Appliance Manager for Kubernetes (kam)	A z/OS UNIX command-line utility that manages the lifecycle of the zCPA.
Kubectl for IBM z/OS (kubectl)	A z/OS UNIX command-line tool for interacting with a Kubernetes cluster, for example, to create deployments.
Kubelet for IBM z/OS (kubelet)	The kubelet is an agent that runs on each system where you want to run a worker node. In zOSCP, you can use the kubelet and kubectl to manage z/OS systems as part of a Kubernetes cluster.
Kubeadm for IBM z/OS (kubeadmz)	A z/OS UNIX command-line utility that provides functions for managing the lifecycle of control plane nodes and worker nodes.
cri-o for IBM z/OS (cri-o)	An implementation of the container runtime interface that is used by Kubernetes to call runC.
crictl for IBM z/OS (crictl)	crictl is the command-line interface for CRI-compatible container runtimes, such as cri-o.

For more information, see What are the Kubernetes components in IBM z/OS Container Platform?.

What are the image management tools?

The following tools are used to work with container images on z/OS.

Component	Description
Podman for IBM z/OS (Podman)	Podman is an open source tool for building and running OCI images.
IBM z/OS for Skopeo (Skopeo)	Skopeo is an open source tool for working with images in image registries.
Umoci for IBM z/OS (umoci)	umoci is an open source tool for modifying Open Container images.

For more information, see What are the image management tools?.

What are the containerized images?

The following images are provided to run containerized applications on z/OS.

Component	Description
z/OS base image	The foundation image, consisting of a basic z/OS UNIX environment with core z/OS programs and libraries.
Java™ image	Builds on the z/OS base image to provide support for Java applications.

For more information, see What are the images provided for IBM z/OS Container Platform?.