Book Image

Learning DevOps - Second Edition

By : Mikael Krief
Book Image

Learning DevOps - Second Edition

By: Mikael Krief

Overview of this book

In the implementation of DevOps processes, the choice of tools is crucial to the sustainability of projects and collaboration between developers and ops. This book presents the different patterns and tools for provisioning and configuring an infrastructure in the cloud, covering mostly open source tools with a large community contribution, such as Terraform, Ansible, and Packer, which are assets for automation. This DevOps book will show you how to containerize your applications with Docker and Kubernetes and walk you through the construction of DevOps pipelines in Jenkins as well as Azure pipelines before covering the tools and importance of testing. You'll find a complete chapter on DevOps practices and tooling for open source projects before getting to grips with security integration in DevOps using Inspec, Hashicorp Vault, and Azure Secure DevOps kit. You'll also learn about the reduction of downtime with blue-green deployment and feature flags techniques before finally covering common DevOps best practices for all your projects. By the end of this book, you'll have built a solid foundation in DevOps and developed the skills necessary to enhance a traditional software delivery process using modern software delivery tools and techniques.
Table of Contents (25 chapters)
1
Section 1: DevOps and Infrastructure as Code
7
Section 2: DevOps CI/CD Pipeline
11
Section 3: Containerized Microservices with Docker and Kubernetes
14
Section 4: Testing Your Application
18
Section 5: Taking DevOps Further/More on DevOps

A first example of Kubernetes application deployment

After installing our Kubernetes cluster, we will deploy an application in it. First of all, it is important to know that when we deploy an application in Kubernetes, we create a new instance of the Docker container in a Kubernetes pod object, so we first need to have a Docker image that contains the application.

For our example, we will use the Docker image that contains a web application that we have pushed into Docker Hub in Chapter 9, Containerizing Your Application with Docker.

To deploy this instance of the Docker container, we will create a new k8sdeploy folder, and inside it, we will create a Kubernetes deployment YAML specification file (myapp-deployment.yml) with the following content:

---
apiVersion: apps/v1
kind: Deployment
metadata:
     name: webapp
spec:
     selector:
     matchLabels:
        ...