You're reading from The Ultimate Docker Container Book Build, test, ship, and run containers with Docker and Kubernetes

Product type Paperback

Published in Aug 2023

Publisher Packt

ISBN-13 9781804613986

Length 626 pages

Edition 3rd Edition

Tools

Docker

Concepts

DevOps

Author (1):

Dr. Gabriel N. Schenker

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Table of Contents (26) Chapters

Preface

1. Part 1:Introduction

2. Chapter 1: What Are Containers and Why Should I Use Them? FREE CHAPTER

3. Chapter 2: Setting Up a Working Environment

4. Part 2:Containerization Fundamentals

5. Chapter 3: Mastering Containers

6. Chapter 4: Creating and Managing Container Images

7. Chapter 5: Data Volumes and Configuration

8. Chapter 6: Debugging Code Running in Containers

9. Chapter 7: Testing Applications Running in Containers

10. Chapter 8: Increasing Productivity with Docker Tips and Tricks

11. Part 3:Orchestration Fundamentals

12. Chapter 9: Learning about Distributed Application Architecture

13. Chapter 10: Using Single-Host Networking

14. Chapter 11: Managing Containers with Docker Compose

15. Chapter 12: Shipping Logs and Monitoring Containers

16. Chapter 13: Introducing Container Orchestration

17. Chapter 14: Introducing Docker Swarm

18. Chapter 15: Deploying and Running a Distributed Application on Docker Swarm

19. Part 4:Docker, Kubernetes, and the Cloud

20. Chapter 16: Introducing Kubernetes

21. Chapter 17: Deploying, Updating, and Securing an Application with Kubernetes

22. Chapter 18: Running a Containerized Application in the Cloud

23. Chapter 19: Monitoring and Troubleshooting an Application Running in Production

24. Index

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The moment we start to work with applications consisting of more than one application service, we need service discovery. The following diagram illustrates this problem:

Figure 16.22 – Service discovery

In the preceding diagram, we have a Web API service that needs access to three other services: payments, shipping, and ordering. The Web API service should never have to care about how and where to find those three services. In the API code, we just want to use the name of the service we want to reach and its port number. A sample would be the following URL, http://payments:3000, which is used to access an instance of the payments service.

In Kubernetes, the payments application service is represented by a ReplicaSet of pods. Due to the nature of highly distributed systems, we cannot assume that pods have stable endpoints. A pod can come and go on a whim. But that’s a problem if we need to access the corresponding application...