Book Image

OpenShift Multi-Cluster Management Handbook

By : Giovanni Fontana, Rafael Pecora
5 (1)
Book Image

OpenShift Multi-Cluster Management Handbook

5 (1)
By: Giovanni Fontana, Rafael Pecora

Overview of this book

For IT professionals working with Red Hat OpenShift Container Platform, the key to maximizing efficiency is understanding the powerful and resilient options to maintain the software development platform with minimal effort. OpenShift Multi-Cluster Management Handbook is a deep dive into the technology, containing knowledge essential for anyone who wants to work with OpenShift. This book starts by covering the architectural concepts and definitions necessary for deploying OpenShift clusters. It then takes you through designing Red Hat OpenShift for hybrid and multi-cloud infrastructure, showing you different approaches for multiple environments (from on-premises to cloud providers). As you advance, you’ll learn container security strategies to protect pipelines, data, and infrastructure on each layer. You’ll also discover tips for critical decision making once you understand the importance of designing a comprehensive project considering all aspects of an architecture that will allow the solution to scale as your application requires. By the end of this OpenShift book, you’ll know how to design a comprehensive Red Hat OpenShift cluster architecture, deploy it, and effectively manage your enterprise-grade clusters and other critical components using tools in OpenShift Plus.
Table of Contents (23 chapters)
1
Part 1 – Design Architectures for Red Hat OpenShift
6
Part 2 – Leverage Enterprise Products with Red Hat OpenShift
11
Part 3 – Multi-Cluster CI/CD on OpenShift Using GitOps
15
Part 4 – A Taste of Multi-Cluster Implementation and Security Compliance
19
Part 5 – Continuous Learning

Understanding misleading error messages

Even if you have learned the different ways to identify a problem, it is not unusual that the error shown does not provide enough information to help you to detect the issue and fix it. Having that in mind, we decided to highlight some very common error messages in this section and also some suggestions to solve the problem.

ImagePullBackOff

This is a common error related to a missing container image. Check out the following lines of code to become familiarized with this kind of issue when you face it:

NAMESPACE   NAME READY STATUS RESTARTS AGE
namespace1  backend-tfmqm 0/1 ImagePullBackOff 0 17h

Here’s a message that may come up when investigating the pod log:

$ oc -n namespace1 logs backend-tfmqm
Error from server (BadRequest): container " backend" in pod " backend-tfmqm" is waiting to start: trying and failing to pull image

Looking at the error message, it is typically linked...