Module 6: Testing and Debugging

Overview

Now that you can build sophisticated operators with webhooks (Module 5), it’s time to learn how to test and debug them effectively. This module covers unit testing with envtest, integration testing, debugging techniques, and observability patterns that make operators production-ready.

Duration: 6-7 hours
Prerequisites:

Completion of Module 1: Kubernetes Architecture Deep Dive
Completion of Module 2: Introduction to Operators
Completion of Module 3: Building Custom Controllers
Completion of Module 4: Advanced Reconciliation Patterns
Completion of Module 5: Webhooks and Admission Control
Understanding of Go testing fundamentals

Learning Objectives

By the end of this module, you will:

Write comprehensive unit tests using envtest
Create integration test suites with Ginkgo/Gomega
Debug operators effectively using Delve and logs
Add observability with metrics, logging, and events
Understand testing best practices for operators

Module Structure

Prerequisites Check

Before starting, ensure you’ve completed:

✅ Module 5: Operator with webhooks
✅ Understand Go testing from Module 2
✅ Have a working operator from Module 3/4/5
✅ Basic understanding of Go testing (go test)

If you haven’t completed Module 5, start with Module 5: Webhooks and Admission Control.

What You’ll Build

Throughout this module, you’ll add testing and observability to your Database operator:

Unit tests for reconciliation logic
Integration tests for end-to-end scenarios
Debugging setup for local development
Metrics and logging for observability

Setup

Before starting this module:

Have your Database operator from Module 3/4/5:
- Should have a working operator
- Webhooks implemented (from Module 5)
- Ready to add tests
Ensure development environment is ready:
```
./scripts/setup-dev-environment.sh
```

Install testing tools:

# Install Ginkgo and Gomega
go install github.com/onsi/ginkgo/v2/ginkgo@latest
   
# Install Delve debugger
go install github.com/go-delve/delve/cmd/dlv@latest

Hands-on Labs

Each lesson includes hands-on exercises that add testing and observability to your operator.

Solutions

Complete working solutions for all labs are available in the solutions directory:

Lab 6.1 Solutions - Test suite setup
Lab 6.2 Solutions - Unit test examples
Lab 6.3 Solutions - Integration test examples
Lab 6.4 Solutions - Metrics, Lab 6.4 Solutions - Observability - Observability examples