Book Image

Introduction to DevOps with Kubernetes

By : Onur Yılmaz, Süleyman Akba≈ü
Book Image

Introduction to DevOps with Kubernetes

By: Onur Yılmaz, Süleyman Akba≈ü

Overview of this book

Kubernetes and DevOps are the two pillars that can keep your business at the top by ensuring high performance of your IT infrastructure. Introduction to DevOps with Kubernetes will help you develop the skills you need to improve your DevOps with the power of Kubernetes. The book begins with an overview of Kubernetes primitives and DevOps concepts. You'll understand how Kubernetes can assist you with overcoming a wide range of real-world operation challenges. You will get to grips with creating and upgrading a cluster, and then learn how to deploy, update, and scale an application on Kubernetes. As you advance through the chapters, you’ll be able to monitor an application by setting up a pod failure alert on Prometheus. The book will also guide you in configuring Alertmanager to send alerts to the Slack channel and trace down a problem on the application using kubectl commands. By the end of this book, you’ll be able to manage the lifecycle of simple to complex applications on Kubernetes with confidence.
Table of Contents (11 chapters)

Chapter 4: Creating a Kubernetes Cluster

Activity 4: Migrating a Running Application in Kubernetes Cluster


Perform the following steps to complete this activity:

  1. Run a sample web application with six replicas in the cluster:
    kubectl run hello-world --replicas=6
    Figure 4.30: Creating hello-world application
  2. Check the status of pods of the sample web application and their nodes:
    kubectl get pods -o wide
    Figure 4.31: Pods and their nodes of the hello-world application
  3. Create a node pool in GCP with a larger memory:
    gcloud container node-pools create high-memory-pool --cluster=devops \
      --machine-type=n1-highmem-2 --num-nodes=2

    Figure 4.32: Node pool creation
    Figure 4.32: Node pool creation
  4. Wait until all nodes are Ready in the cluster:
    kubectl get nodes
    Figure 4.33: Kubernetes nodes after pool creation
  5. Mark the nodes in the default node pool as unschedulable and make Kubernetes move the workloads...