Learn Helm: Improve productivity, reduce complexity, and speed up cloud-native adoption with Helm for Kubernetes

Cover
Title page
Copyright
Credits
About Packt
Contributors
Table of Contents
Preface
Section 1: Introduction and Setup
Chapter 1: Understanding Kubernetes and Helm
From monoliths to modern microservices
What is Kubernetes?
Container Orchestration
High availability
Scalability
Active community
Deploying a Kubernetes application
Deployment
Services
PersistentVolumeClaim
Approaches in resource management
Imperative and declarative configuration
Resource configuration challenges
The many types of Kubernetes resources
Keeping the live and local states in sync
Application life cycles are hard to manage
Resource files are static
Helm to the rescue!
Understanding package managers
The Kubernetes package manager
Summary
Further reading
Questions
Chapter 2: Preparing a Kubernetes and Helm Environment
Technical requirements
Preparing a local Kubernetes environment with Minikube
Installing Minikube
Installing VirtualBox
Configuring VirtualBox as the designated hypervisor
Configuring Minikube resource allocation
Exploring the basic usage
Setting up Kubectl
Installing Kubectl
Setting up Helm
Installing Helm
Configuring Helm
Adding upstream repositories
Adding plugins
Environment variables
Tab completion
Authentication
Authorization/RBAC
Summary
Further reading
Questions
Chapter 3: Installing your First Helm Chart
Technical requirements
Understanding the WordPress application
Finding a WordPress chart
Searching for WordPress charts from the command line
Viewing the WordPress chart in a browser
Showing the WordPress chart information from the command line
Creating a Kubernetes environment
Installing the WordPress chart
Creating a values file for configuration
Running the installation
Inspecting your release
Additional installation notes
The -n flag
The HELM_NAMESPACE environment variable
Choosing between --set and --values
Accessing the WordPress application
Upgrading the WordPress release
Modifying the Helm values
Running the upgrade
Reusing and resetting values during an upgrade
Rolling back the WordPress release
Inspecting the WordPress history
Running the rollback
Uninstalling the WordPress release
Cleaning up your environment
Summary
Further reading
Questions
Section 2: Helm Chart Development
Chapter 4: Understanding Helm Charts
Technical requirements
Understanding the YAML format
Defining key-value pairs
Value types
Understanding chart templates
Go templating
Understanding chart definitions
Required fields
Optional metadata
Managing chart dependencies
Downloading dependencies
Conditional dependencies
Overriding and referencing values from a child chart
Importing values with import-values
Life cycle management
The basics of a Helm hook
Hook execution
Advanced hook concepts
Documenting a Helm chart
The README.md File
The LICENSE file
The templates/NOTES.txt file
Packaging a Helm chart
Summary
Further reading
Questions
Chapter 5: Building Your First Helm Chart
Technical requirements
Understanding the Guestbook application
Setting up the environment
Creating a Guestbook Helm chart
Scaffolding the initial file structure
Evaluating the chart definition
Adding a Redis chart dependency
Modifying the values.yaml file
Installing the Guestbook chart
Improving the Guestbook Helm chart
Creating pre-upgrade and pre-rollback life cycle hooks
Adding input validation
Publishing the Guestbook chart to a chart repository
Creating a chart repository
Publishing the Guestbook Helm chart
Adding your chart repository
Cleaning up
Summary
Further reading
Questions
Chapter 6: Testing Helm Charts
Technical requirements
Setting up your environment
Verifying Helm templating
Validating template generation locally with helm template
Linting Helm charts and templates
Testing in a live cluster
Creating the chart tests
Running the chart tests
Improving chart tests with the chart testing project
Introducing the chart testing project
Installing the chart testing tools
Cleaning up
Summary
Further reading
Questions
Section 3: Adanced Deployment Patterns
Chapter 7: Automating Helm Processes Using CI/CD and GitOps
Technical requirements
Understanding CI/CD and GitOps
CI/CD
Taking CI/CD to the next level using GitOps
Setting up our environment
Creating a CI pipeline to build Helm charts
Designing the pipeline
Understanding Jenkins
Installing Jenkins
Understanding the pipeline
Running the pipeline
Creating a CD pipeline to deploy applications with Helm
Designing the pipeline
Updating the environments
Understanding the pipeline
Running the pipeline
Cleaning up
Summary
Further reading
Questions
Chapter 8: Using Helm with the Operator Framework
Technical requirements
Understanding Kubernetes Operators
Creating a Helm operator
Setting up the environment
Scaffolding the operator file structure
Building the operator and pushing it to Quay
Deploying the Guestbook Operator
Deploying the Guestbook application
Using Helm to manage Operators and CRs
Cleaning up your Kubernetes environment
Summary
Further reading
Questions
Chapter 9: Helm Security Considerations
Technical requirements
Data provenance and integrity
Creating a GPG keypair
Verifying Helm downloads
Signing and verifying Helm charts
Developing secure Helm charts
Using secure images
Setting resource limits
Handling secrets in Helm charts
Configuring RBAC rules
Accessing secure chart repositories
Summary
Further reading
Questions
ASSESSMENTS
Chapter 1: Understanding Kubernetes and Helm
Chapter 2: Preparing a Kubernetes and Helm Environment
Chapter 3: Installing Your First Helm Chart
Chapter 4: Understanding Helm Charts
Chapter 5: Building Your First Helm Chart
Chapter 6: Testing Helm Charts
Chapter 7: Automating Helm Processes Using CI/CD and GitOps
Chapter 8: Using Helm with the Operator Framework
Chapter 9: Helm Security Considerations
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