Crossplane Fundamentals¶

Welcome to the Crossplane v2.0 learning journey! In this section, you'll transform from a Crossplane beginner to someone who can provision real Azure infrastructure using GitOps workflows.

What Makes Crossplane v2.0 Different¶

Crossplane v2.0 introduces a namespace-first architecture that makes building control planes more intuitive and powerful:

🏗️ Namespaced Everything¶

Composite Resources (XRs) live in user namespaces, not cluster-wide
Managed Resources are namespaced for better isolation and RBAC
No more Claims - developers work directly with XRs

🔧 Composition Functions Only¶

Native patch & transform removed - functions provide more flexibility
Pipeline-based compositions with reusable function libraries
Any Kubernetes resource can be composed, not just managed resources

🎯 Cleaner Developer Experience¶

spec.crossplane groups all Crossplane machinery for clarity
Direct resource creation without intermediate claim objects
Better namespace isolation for teams and projects

What You'll Build¶

By the end of these modules, you'll have:

✅ Secure Azure Provider configured with Sealed Secrets
✅ Real Cloud Infrastructure provisioned via Git commits
✅ Production-Ready Security following best practices
✅ GitOps Workflows for infrastructure management

Learning Philosophy: "Build First, Understand Later"¶

We start with working examples that demonstrate immediate value, then dive deeper into concepts. Every exercise follows GitOps principles from day one and produces production-ready artifacts.

Prerequisites¶

Before starting this section, ensure you have completed:

Azure Account Requirements¶

You'll need an active Azure subscription with:

✅ Subscription access to create resources
✅ Permission to create service principals
✅ Azure CLI configured and authenticated

Namespace Strategy for v2.0¶

In Crossplane v2.0, namespaces provide natural boundaries for:

Resource Organization¶

tutorial/              # Learning resources
├── ResourceGroups
├── VirtualNetworks    
└── XDevEnvironments

production/           # Production workloads
├── Databases
├── AKSClusters
└── XProdEnvironments

Team Isolation¶

frontend-team namespace for UI-focused resources
backend-team namespace for API and data resources
platform-team namespace for shared infrastructure

RBAC Benefits¶

Fine-grained permissions per namespace
Team-specific resource access
Natural audit boundaries

For this tutorial: We'll use the tutorial namespace to keep all learning resources organized and isolated from other workloads.

Function-Based Composition in v2¶

Crossplane v2 moves from native patch-and-transform to function pipelines. Understanding functions is crucial for v2 success:

Core Functions You'll Use¶

function-patch-and-transform: YAML-based transformations (most common)
function-python: Python scripting for complex logic
function-kcl: KCL configuration language for validation
function-go-templating: Go templates for dynamic generation

Function Installation Pattern¶

apiVersion: pkg.crossplane.io/v1beta1
kind: Function
metadata:
  name: function-patch-and-transform
spec:
  package: xpkg.upbound.io/crossplane-contrib/function-patch-and-transform:v0.2.1

Pipeline Execution¶

apiVersion: apiextensions.crossplane.io/v1
kind: Composition
spec:
  mode: Pipeline  # v2 default
  pipeline:
  - step: patch-resources
    functionRef:
      name: function-patch-and-transform
    input:
      apiVersion: pt.fn.crossplane.io/v1beta1
      kind: Resources
      # Function-specific configuration

When You'll Learn Functions¶

Module 2: Basic function installation and usage
Advanced Patterns: Complex function pipelines and custom logic
Troubleshooting: Function debugging techniques

Module Overview¶

Module 1: Azure Provider Setup (15 minutes)¶

Objective: Configure Crossplane to securely manage Azure resources

What you'll learn:
- How to install Azure provider in Crossplane
- Secure credential management with Sealed Secrets
- Provider configuration and verification
- GitOps deployment of provider components

Deliverables:
- Azure provider installed and configured
- Service principal credentials securely stored
- Provider health verification

Module 2: Your First Managed Resource (15 minutes)¶

Objective: Deploy a real Azure resource using Crossplane

What you'll learn:
- What are Managed Resources (MRs)
- How to create Azure Resource Groups
- GitOps workflow for resource deployment
- Resource status monitoring and troubleshooting

Deliverables:
- Azure Resource Group deployed via Git
- Understanding of resource lifecycle
- ArgoCD application managing infrastructure

Module 3: Understanding What Happened (15 minutes)¶

Objective: Explore the Crossplane resource model and reconciliation

What you'll learn:
- Crossplane architecture and components
- Resource states and conditions
- Troubleshooting resource issues
- Best practices for resource management

Deliverables:
- Deep understanding of Crossplane concepts
- Troubleshooting skills and techniques
- Foundation for advanced patterns

Operations in Crossplane v2 (Alpha Feature)¶

Crossplane v2 introduces Operations - an alpha feature for operational workflows that run to completion like Kubernetes Jobs:

Operation Types¶

Operation: Run function pipeline once
CronOperation: Scheduled function execution
WatchOperation: Event-driven function triggers

Use Cases¶

Certificate renewal: Automated cert lifecycle management
Database backups: Scheduled backup operations
Health monitoring: Periodic health checks and reporting
Configuration drift: Automated configuration validation

Example: Daily Database Backup¶

apiVersion: ops.crossplane.io/v1alpha1
kind: CronOperation
metadata:
  name: backup-postgres
  namespace: production
spec:
  schedule: "0 2 * * *"  # Daily at 2 AM
  mode: Pipeline
  pipeline:
  - step: backup-database
    functionRef:
      name: function-python

Enabling Operations¶

Operations must be explicitly enabled:

# Add to Crossplane deployment
--enable-operations=true

Note: Operations are alpha in v2 and may change. We'll cover them in advanced patterns once you master the core concepts.

Success Criteria¶

After completing this section, you should be able to:

Explain the relationship between Providers, ProviderConfigs, and Managed Resources
Create Azure resources using Crossplane and GitOps workflows
Troubleshoot common resource provisioning issues
Follow security best practices for cloud credentials
Use ArgoCD to deploy and manage infrastructure components

Time Investment¶

Total time: ~45 minutes of hands-on exercises Format: Self-paced with immediate feedback Approach: Practical exercises with real Azure resources

Next Steps¶

Ready to get started? Let's begin with setting up the Azure provider:

➡️ Module 1: Azure Provider Setup