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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Exploring high-availability and fault-tolerance

The cluster would not be reliable if it wouldn't be fault tolerant. Kops intents to make it so, but we're going to validate that anyways.

Let's retrieve the list of worker node instances:

aws ec2 \
    describe-instances | jq -r \
    ".Reservations[].Instances[] \
    | select(.SecurityGroups[]\

We used aws ec2 describe-instances to retrieve all the instances (five in total). The output was sent to jq, which filtered them by the security group dedicated to worker nodes.

The output is as follows:


We'll terminate one of the worker nodes. To do that, we'll pick a random one, and retrieve its ID.

INSTANCE_ID=$(aws ec2 \
    describe-instances | jq -r \
    ".Reservations[].Instances[] \