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Getting Started With z/OS Container Extensions and Docker

Joseph Gulla focuses on the 2019 IBM Redbooks publication titled “Getting Started with z/OS Container Extensions and Docker." 

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This week, I’ll continue with this series on the recent 2019 IBM Redbooks publications with a focus on “Getting Started with z/OS Container Extensions and Docker." This publication helps you understand the concepts, business perspectives and reference architecture for installing, tailoring and configuring z/OS Container Extensions (zCX) in your own environment. You can now run Docker Containers in z/OS because you can more easily integrate and manage Linux applications in Docker Containers that work cooperatively with your CICS and IMS applications on z/OS, and that’s a big deal.

Watch the Video

A great way to get started with this publication is to watch the short video that’s available on the main page for the Redbook publication. It’s called “An Overview of IBM z/OS Container Extensions.” The video introduces you, in a simple way, to every topic you need to know to catch up with the main ideas explained in the publication. The video explains concepts such as z/OS applications of record and Linux applications of engagement. It explains Docker Containers and the feature called IBM z/OS Container Extensions, which is a new component of z/OS V2.4. The presentation is made by one of the authors, Subhajit Maitra.

How to Appreciate the Publication

There are 11 chapters in the publication. Some chapters, such as the introduction, are for every reader. Others are specialized for system programmers (“zCX Planning”) and application developers (“Your First Running Docker Container in zCX”). The Redbooks publication has just about every potential modernization team member covered. Here’s a summary of what you will find in the chapters.
  1. The introduction is a useful chapter for all readers as it contains a z/OS container extensions overview, covers container concepts, zCX architecture and answers the question “Why use z/OS container extensions?”
  2. “z/OS Container Extensions Planning” covers prerequisites, planning for containers, private registry considerations, and backup and recovery considerations
  3. “Security – Overview” explains zCX instance security, security within the zCX instance and Docker in zCX versus Docker in distributed environments
  4. At the end of the process explained in “Provisioning and Managing Your First z/OS Container,” you have a zCX instance that’s ready to run Docker containers.
  5. “Your First Running Docker Container in zCX” describes how to get an image running in a zCX instance. The sections start with an easy example then moves on to a more sophisticated level where configure an HTTP server.
  6. “Private Registry Implementation” explains the Docker registry, which is one of the main components in a container environment
  7. Operation covers running and maintaining zCX, including software maintenance, automation, backup and recovery, diagnosis, monitoring with RMF, and configuring Grafana to monitor zCX containers
  8. “Integrating Container Applications With Other Processes on z/OS” provides sample scenarios on how to architect, build and deploy a hybrid solution that consists of two components on the same z/OS platform: z/OS software and Linux on Z Docker Containers. This is a key topic because you want to exploit one of the most important reasons to have these different systems on the same computer and OS.
  9. “zCX User Administration” is focused on how to configure a zCX instance to use an existing LDAP server for authentication
  10. “Persistent Data provides information about persistent data and how it’s important in the container world. Persistent data is data that you want to be available, even if the container is removed.
  11. “Swarm on zCX” explains how to set up multiple Docker hosts, which run in swarm mode and act as managers (to manage membership and delegation) and workers (which run swarm services)
The publication is a great way to get an introduction to the topic and get access to a wide variety of necessary technical details. If hands-on experience is important to you, Chapter 5 describes how to get an image running in your zCX instance, which is very useful.

Next Post

Next post, I’ll look back on 2019 and highlight some of the most interesting series of topics that I explored throughout the year.
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