Kubernetes: Up and Running: Dive into the Future of Infrastructure

Cover
Copyright
Table of Contents
Preface
Who Should Read This Book
Why We Wrote This Book
Why We Updated This Book
A Word on Cloud Native Applications Today
Navigating This Book
Online Resources
Conventions Used in This Book
Using Code Examples
O’Reilly Online Learning
How to Contact Us
Acknowledgments
Chapter 1. Introduction
Velocity
The Value of Immutability
Declarative Configuration
Self-Healing Systems
Scaling Your Service and Your Teams
Decoupling
Easy Scaling for Applications and Clusters
Scaling Development Teams with Microservices
Separation of Concerns for Consistency and Scaling
Abstracting Your Infrastructure
Efficiency
Cloud Native Ecosystem
Summary
Chapter 2. Creating and Running Containers
Container Images
Building Application Images with Docker
Dockerfiles
Optimizing Image Sizes
Image Security
Multistage Image Builds
Storing Images in a Remote Registry
The Container Runtime Interface
Running Containers with Docker
Exploring the kuard Application
Limiting Resource Usage
Cleanup
Summary
Chapter 3. Deploying a Kubernetes Cluster
Installing Kubernetes on a Public Cloud Provider
Installing Kubernetes with Google Kubernetes Engine
Installing Kubernetes with Azure Kubernetes Service
Installing Kubernetes on Amazon Web Services
Installing Kubernetes Locally Using minikube
Running Kubernetes in Docker
The Kubernetes Client
Checking Cluster Status
Listing Kubernetes Nodes
Cluster Components
Kubernetes Proxy
Kubernetes DNS
Kubernetes UI
Summary
Chapter 4. Common kubectl Commands
Namespaces
Contexts
Viewing Kubernetes API Objects
Creating, Updating, and Destroying Kubernetes Objects
Labeling and Annotating Objects
Debugging Commands
Cluster Management
Command Autocompletion
Alternative Ways of Viewing Your Cluster
Summary
Chapter 5. Pods
Pods in Kubernetes
Thinking with Pods
The Pod Manifest
Creating a Pod
Creating a Pod Manifest
Running Pods
Listing Pods
Pod Details
Deleting a Pod
Accessing Your Pod
Getting More Information with Logs
Running Commands in Your Container with exec
Copying Files to and from Containers
Health Checks
Liveness Probe
Readiness Probe
Startup Probe
Advanced Probe Configuration
Other Types of Health Checks
Resource Management
Resource Requests: Minimum Required Resources
Capping Resource Usage with Limits
Persisting Data with Volumes
Using Volumes with Pods
Different Ways of Using Volumes with Pods
Putting It All Together
Summary
Chapter 6. Labels and Annotations
Labels
Applying Labels
Modifying Labels
Label Selectors
Label Selectors in API Objects
Labels in the Kubernetes Architecture
Annotations
Cleanup
Summary
Chapter 7. Service Discovery
What Is Service Discovery?
The Service Object
Service DNS
Readiness Checks
Looking Beyond the Cluster
Load Balancer Integration
Advanced Details
Endpoints
Manual Service Discovery
kube-proxy and Cluster IPs
Cluster IP Environment Variables
Connecting with Other Environments
Connecting to Resources Outside of a Cluster
Connecting External Resources to Services Inside a Cluster
Cleanup
Summary
Chapter 8. HTTP Load Balancing with Ingress
Ingress Spec Versus Ingress Controllers
Installing Contour
Configuring DNS
Configuring a Local hosts File
Using Ingress
Simplest Usage
Using Hostnames
Using Paths
Cleanup
Advanced Ingress Topics and Gotchas
Running Multiple Ingress Controllers
Multiple Ingress Objects
Ingress and Namespaces
Path Rewriting
Serving TLS
Alternate Ingress Implementations
The Future of Ingress
Summary
Chapter 9. ReplicaSets
Reconciliation Loops
Relating Pods and ReplicaSets
Adopting Existing Containers
Quarantining Containers
Designing with ReplicaSets
ReplicaSet Spec
Pod Templates
Labels
Creating a ReplicaSet
Inspecting a ReplicaSet
Finding a ReplicaSet from a Pod
Finding a Set of Pods for a ReplicaSet
Scaling ReplicaSets
Imperative Scaling with kubectl scale
Declaratively Scaling with kubectl apply
Autoscaling a ReplicaSet
Deleting ReplicaSets
Summary
Chapter 10. Deployments
Your First Deployment
Creating Deployments
Managing Deployments
Updating Deployments
Scaling a Deployment
Updating a Container Image
Rollout History
Deployment Strategies
Recreate Strategy
RollingUpdate Strategy
Slowing Rollouts to Ensure Service Health
Deleting a Deployment
Monitoring a Deployment
Summary
Chapter 11. DaemonSets
DaemonSet Scheduler
Creating DaemonSets
Limiting DaemonSets to Specific Nodes
Adding Labels to Nodes
Node Selectors
Updating a DaemonSet
Deleting a DaemonSet
Summary
Chapter 12. Jobs
The Job Object
Job Patterns
One Shot
Parallelism
Work Queues
CronJobs
Summary
Chapter 13. ConfigMaps and Secrets
ConfigMaps
Creating ConfigMaps
Using a ConfigMap
Secrets
Creating Secrets
Consuming Secrets
Private Container Registries
Naming Constraints
Managing ConfigMaps and Secrets
Listing
Creating
Updating
Summary
Chapter 14. Role-Based Access Control for Kubernetes
Role-Based Access Control
Identity in Kubernetes
Understanding Roles and Role Bindings
Roles and Role Bindings in Kubernetes
Techniques for Managing RBAC
Testing Authorization with can-i
Managing RBAC in Source Control
Advanced Topics
Aggregating ClusterRoles
Using Groups for Bindings
Summary
Chapter 15. Service Meshes
Encryption and Authentication with Mutal TLS
Traffic Shaping
Introspection
Do You Really Need a Service Mesh?
Introspecting a Service Mesh Implementation
Service Mesh Landscape
Summary
Chapter 16. Integrating Storage Solutions and Kubernetes
Importing External Services
Services Without Selectors
Limitations of External Services: Health Checking
Running Reliable Singletons
Running a MySQL Singleton
Dynamic Volume Provisioning
Kubernetes-Native Storage with StatefulSets
Properties of StatefulSets
Manually Replicated MongoDB with StatefulSets
Automating MongoDB Cluster Creation
Persistent Volumes and StatefulSets
One Final Thing: Readiness Probes
Summary
Chapter 17. Extending Kubernetes
What It Means to Extend Kubernetes
Points of Extensibility
Patterns for Custom Resources
Just Data
Compilers
Operators
Getting Started
Summary
Chapter 18. Accessing Kubernetes from Common Programming Languages
The Kubernetes API: A Client’s Perspective
OpenAPI and Generated Client Libraries
But What About kubectl x?
Programming the Kubernetes API
Installing the Client Libraries
Authenticating to the Kubernetes API
Accessing the Kubernetes API
Putting It All Together: Listing and Creating Pods in Python, Java, and .NET
Creating and Patching Objects
Watching Kubernetes APIs for Changes
Interacting with Pods
Summary
Chapter 19. Securing Applications in Kubernetes
Understanding SecurityContext
SecurityContext Challenges
Pod Security
What Is Pod Security?
Applying Pod Security Standards
Service Account Management
Role-Based Access Control
RuntimeClass
Network Policy
Service Mesh
Security Benchmark Tools
Image Security
Summary
Chapter 20. Policy and Governance for Kubernetes Clusters
Why Policy and Governance Matter
Admission Flow
Policy and Governance with Gatekeeper
What Is Open Policy Agent?
Installing Gatekeeper
Configuring Policies
Understanding Constraint Templates
Creating Constraints
Audit
Mutation
Data Replication
Metrics
Policy Library
Summary
Chapter 21. Multicluster Application Deployments
Before You Even Begin
Starting at the Top with a Load-Balancing Approach
Building Applications for Multiple Clusters
Replicated Silos: The Simplest Cross-Regional Model
Sharding: Regional Data
Better Flexibility: Microservice Routing
Summary
Chapter 22. Organizing Your Application
Principles to Guide Us
Filesystems as the Source of Truth
The Role of Code Review
Feature Gates
Managing Your Application in Source Control
Filesystem Layout
Managing Periodic Versions
Structuring Your Application for Development, Testing, and Deployment
Goals
Progression of a Release
Parameterizing Your Application with Templates
Parameterizing with Helm and Templates
Filesystem Layout for Parameterization
Deploying Your Application Around the World
Architectures for Worldwide Deployment
Implementing Worldwide Deployment
Dashboards and Monitoring for Worldwide Deployments
Summary
Appendix A. Building Your Own Kubernetes Cluster
Parts List
Flashing Images
First Boot
Setting Up Networking
Installing a Container Runtime
Installing Kubernetes
Setting Up the Cluster
Setting Up Cluster Networking
Summary
Index
About the Authors
Colophon