Book Image

The DevOps 2.3 Toolkit

By : Viktor Farcic
Book Image

The DevOps 2.3 Toolkit

By: Viktor Farcic

Overview of this book

Building on The DevOps 2.0 Toolkit, The DevOps 2.1 Toolkit: Docker Swarm, and The DevOps 2.2 Toolkit: Self-Sufficient Docker Clusters, Viktor Farcic brings his latest exploration of the DevOps Toolkit as he takes you on a journey to explore the features of Kubernetes. The DevOps 2.3 Toolkit: Kubernetes is a book in the series that helps you build a full DevOps Toolkit. This book in the series looks at Kubernetes, the tool designed to, among other roles, make it easier in the creation and deployment of highly available and fault-tolerant applications at scale, with zero downtime. Within this book, Viktor will cover a wide range of emerging topics, including what exactly Kubernetes is, how to use both first and third-party add-ons for projects, and how to get the skills to be able to call yourself a “Kubernetes ninja.” Work with Viktor and dive into the creation and exploration of Kubernetes with a series of hands-on guides.
Table of Contents (18 chapters)
The End
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Rolling back failed Deployments

Discovering a critical bug is probably the most common reason for a rollback. Still, there are others. For example, we might be in a situation when Pods cannot be created. An easy to reproduce case would be an attempt to deploy an image with a tag that does not exist.

kubectl set image \
    -f deploy/go-demo-2-api.yml \
    api=vfarcic/go-demo-2:does-not-exist \

The output is as follows:

deployment "go-demo-2-api" image updated  

After seeing such a message, you might be under the impression that everything is OK. However, that output only indicates that the definition of the image used in the Deployment was successfully updated. That does not mean that the Pods behind the ReplicaSet are indeed running. For one, I can assure you that the vfarcic/go-demo-2:does-not-exist image does not exist.

Please make sure that at least...