Kubernetes Patterns: Reusable Elements for Designing Cloud Native Applications (2nd Ed)

What’s New in the Second Edition The Kubernetes ecosystem has continued to grow since the first edition came out four years ago. As a result, there have been many Kubernetes releases, and more tools and patterns for using Kubernetes have become de facto standards. Fortunately, most of the patterns described in our book have stood the test of time and remain valid. Therefore, we have updated these patterns, added new features up to Kubernetes 1.26, and removed obsolete and deprecated parts. For the most part, only minor changes were necessary, except for Chapter 29, “Elastic Scale”, and Chapter 30, “Image Builder”, which underwent significant changes due to new developments in these areas. Additionally, we have included five new patterns and introduced a new category, Part V, “Security Patterns”, which addresses a gap in the first edition and provides important security-related patterns for developers. Our GitHub examples have been updated and extended. And, lastly, we added 50% more content for our readers to enjoy. Kubernetes Patterns The way developers design, build, and run software has changed significantly with the evolution of microservices and containers. These modern architectures offer new distributed primitives that require a different set of practices than many developers, tech leads, and architects are accustomed to. With this focused guide, Bilgin Ibryam and Roland Huß provide common reusable patterns and principles for designing and implementing cloud native applications on Kubernetes. Each pattern includes a description of the problem and a Kubernetes-specific solution. All patterns are backed by and demonstrated with concrete code examples. This updated edition is ideal for developers and architects who are familiar with basic Kubernetes concepts but want to learn how to solve common cloud native challenges with proven design patterns. Cover Red Hat Copyright Table of Contents Foreword Preface Kubernetes Design Patterns How This Book Is Structured Who This Book Is For What You Will Learn What’s New in the Second Edition Conventions Used in This Book Using Code Examples O’Reilly Online Learning How to Contact Us Acknowledgments Chapter 1. Introduction The Path to Cloud Native Distributed Primitives Containers Pods Services Labels Namespaces Discussion More Information Part I. Foundational Patterns Chapter 2. Predictable Demands Problem Solution Runtime Dependencies Resource Profiles Pod Priority Project Resources Capacity Planning Discussion More Information Chapter 3. Declarative Deployment Problem Solution Rolling Deployment Fixed Deployment Blue-Green Release Canary Release Discussion More Information Chapter 4. Health Probe Problem Solution Process Health Checks Liveness Probes Readiness Probes Startup Probes Discussion More Information Chapter 5. Managed Lifecycle Problem Solution SIGTERM Signal SIGKILL Signal PostStart Hook PreStop Hook Other Lifecycle Controls Discussion More Information Chapter 6. Automated Placement Problem Solution Available Node Resources Container Resource Demands Scheduler Configurations Scheduling Process Node Affinity Pod Affinity and Anti-Affinity Topology Spread Constraints Taints and Tolerations Discussion More Information Part II. Behavioral Patterns Chapter 7. Batch Job Problem Solution Discussion More Information Chapter 8. Periodic Job Problem Solution Discussion More Information Chapter 9. Daemon Service Problem Solution Discussion More Information Chapter 10. Singleton Service Problem Solution Out-of-Application Locking In-Application Locking Pod Disruption Budget Discussion More Information Chapter 11. Stateless Service Problem Solution Instances Networking Storage Discussion More Information Chapter 12. Stateful Service Problem Storage Networking Identity Ordinality Other Requirements Solution Storage Networking Identity Ordinality Other Features Discussion More Information Chapter 13. Service Discovery Problem Solution Internal Service Discovery Manual Service Discovery Service Discovery from Outside the Cluster Application Layer Service Discovery Discussion More Information Chapter 14. Self Awareness Problem Solution Discussion More Information Part III. Structural Patterns Chapter 15. Init Container Problem Solution Discussion More Information Chapter 16. Sidecar Problem Solution Discussion More Information Chapter 17. Adapter Problem Solution Discussion More Information Chapter 18. Ambassador Problem Solution Discussion More Information Part IV. Configuration Patterns Chapter 19. EnvVar Configuration Problem Solution Discussion More Information Chapter 20. Configuration Resource Problem Solution Discussion More Information Chapter 21. Immutable Configuration Problem Solution Docker Volumes Kubernetes Init Containers OpenShift Templates Discussion More Information Chapter 22. Configuration Template Problem Solution Discussion More Information Part V. Security Patterns Chapter 23. Process Containment Problem Solution Running Containers with a Non-Root User Restricting Container Capabilities Avoiding a Mutable Container Filesystem Enforcing Security Policies Discussion More Information Chapter 24. Network Segmentation Problem Solution Network Policies Authentication Policies Discussion More Information Chapter 25. Secure Configuration Problem Solution Out-of-Cluster Encryption Centralized Secret Management Discussion More Information Chapter 26. Access Control Problem Solution Authentication Authorization Admission Controllers Subject Role-Based Access Control Discussion More Information Part VI. Advanced Patterns Chapter 27. Controller Problem Solution Discussion More Information Chapter 28. Operator Problem Solution Custom Resource Definitions Controller and Operator Classification Operator Development and Deployment Example Discussion More Information Chapter 29. Elastic Scale Problem Solution Manual Horizontal Scaling Horizontal Pod Autoscaling Vertical Pod Autoscaling Cluster Autoscaling Scaling Levels Discussion More Information Chapter 30. Image Builder Problem Solution Container Image Builder Build Orchestrators Build Pod OpenShift Build Discussion More Information Afterword What We Covered Final Words Index About the Authors Colophon The way developers design, build, and run software has changed significantly with the evolution of microservices and containers. These modern architectures offer new distributed primitives that require a different set of practices than many developers, tech leads, and architects are accustomed to. With this focused guide, Bilgin Ibryam and Roland Huss provide common reusable patterns and principles for designing and implementing cloud native applications on Kubernetes.Each pattern includes a description of the problem and a Kubernetes-specific solution. All patterns are backed by and demonstrated with concrete code examples. This updated edition is ideal for developers and architects familiar with basic Kubernetes concepts who want to learn how to solve common cloud native challenges with proven design patterns.You'll explore:Foundational patterns covering core principles and practices for building and running container-based cloud native applicationsBehavioral patterns that delve into finer-grained concepts for managing various types of container and platform interactionsStructural patterns for organizing containers within a Pod for addressing specific use casesConfiguration patterns that provide insight into how application configurations can be handled in KubernetesSecurity patterns for hardening the access to cloud native applications running on KubernetesAdvanced patterns covering more complex topics such as operators and autoscaling