Lab 06 · GitOps Workflows

DevOps Studio › Labs › Lab 06 · ⏱ 1–2 hours · Intermediate

Let Git drive your deployments. By the end you'll manage environments with Kustomize and have Argo CD (or Flux) continuously reconcile the cluster to match what's committed in Git.

On this page: Architecture · Prerequisites · Quick Start · Detailed Setup · Project Structure · Kustomize · Troubleshooting · Cleanup

What you build

Kustomize — a base plus staging and production overlays
Argo CD — Git-driven deployments with a UI
Flux — a CLI-based alternative
Automatic sync & drift detection

Skills you'll practice: GitOps principles · Kustomize overlays · Argo CD · Flux · reconciliation and drift detection · environment promotion.

Architecture

Lab 06 — GitOps reconciliation of desired and actual state

GitOps Workflow

Developer commits changes to Git
Kustomize generates environment-specific YAML
Argo CD/Flux detects Git changes
Argo CD/Flux applies changes to cluster
Application is automatically updated

Prerequisites

Required Tools

Tool	Version	Purpose
kubectl	1.32+	Kubernetes cluster management
kustomize	4.5+	Configuration management
Helm	3.10+	Package management
Git	2.30+	Version control

AWS Requirements

EKS Cluster from Lab 02 (or existing Kubernetes cluster)
kubectl configured to access the cluster
Git repository (GitHub, GitLab, etc.)

Knowledge Prerequisites

Basic Kubernetes concepts
Understanding of Lab 02 (Kubernetes Platform)
Basic Git knowledge

Lab Dependencies

Required: Complete Lab 02 first to have an EKS cluster.

Quick Start

For experienced users who want to deploy immediately:

bash

# 1. Navigate to lab directory
cd labs/06-gitops-workflows

# 2. Choose your GitOps tool (Argo CD or Flux)
# For Argo CD (visual):
make install-argocd

# For Flux (CLI):
make install-flux

# 3. Set up Kustomize base and overlays
make setup-kustomize

# 4. Verify installation
make status

Setup time: ~20-30 minutes
Estimated cost: $1-3 to complete (vs $20-30/month if kept running)

Detailed Setup

Step 1: Verify Cluster Access

bash

# Check kubectl is configured
kubectl cluster-info
kubectl get nodes

Step 2: Set Up Kustomize

bash

# Create base and overlay structure
make setup-kustomize

# Build staging configuration
kubectl kustomize kustomize/overlays/staging

# Build production configuration
kubectl kustomize kustomize/overlays/production

Step 3: Choose Your GitOps Tool

Option A: Argo CD (Visual Dashboard)

bash

make install-argocd
# Access UI at: https://localhost:8080 (port-forward)

Option B: Flux (CLI-Focused)

bash

make install-flux
# Manage via flux CLI

Step 4: Configure GitOps

bash

# For Argo CD
make configure-argocd

# For Flux
make configure-flux

Project Structure

labs/06-gitops-workflows/
├── README.md                    # This file
├── Makefile                     # Automation commands
├── kustomize/                   # Kustomize configurations
│   ├── base/                    # Base manifests
│   │   ├── kustomization.yaml
│   │   ├── deployment.yaml
│   │   ├── service.yaml
│   │   └── configmap.yaml
│   └── overlays/                # Environment overlays
│       ├── staging/
│       │   ├── kustomization.yaml
│       │   └── patches/
│       └── production/
│           ├── kustomization.yaml
│           └── patches/
├── argocd/                      # Argo CD configuration
│   ├── README.md
│   ├── application.yaml        # App definition
│   └── values.yaml             # Helm values
├── flux/                        # Flux configuration
│   ├── README.md
│   ├── gitrepository.yaml      # Git source
│   └── kustomization.yaml      # Kustomize deployment
├── TOOL-COMPARISON.md          # Detailed comparison
└── scripts/                     # Automation scripts
    ├── validate.sh
    └── test-gitops.sh

Kustomize

Kustomize helps you manage Kubernetes YAML files across multiple environments.

Base Configuration

The base/ directory contains common configurations:

yaml

# kustomize/base/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

resources:
  - deployment.yaml
  - service.yaml
  - configmap.yaml

commonLabels:
  app: sample-app
  managed-by: kustomize

Environment Overlays

The overlays/ directory contains environment-specific patches:

yaml

# kustomize/overlays/staging/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

bases:
  - ../../base

replicas:
  - name: sample-app
    count: 2

patches:
  - path: patches/resource-limits.yaml

namespace: staging

See kustomize/README.md for detailed usage.

Argo CD

Argo CD provides a visual GitOps platform with a web dashboard.

Installation

bash

make install-argocd

Application Definition

yaml

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: sample-app
spec:
  project: default
  source:
    repoURL: https://github.com/your-org/your-repo
    targetRevision: main
    path: kustomize/overlays/staging
    kustomize: {}
  destination:
    server: https://kubernetes.default.svc
    namespace: staging
  syncPolicy:
    automated:
      prune: true
      selfHeal: true

Accessing the UI

bash

# Port-forward to access UI
kubectl port-forward svc/argocd-server -n argocd 8080:443

# Get admin password
kubectl -n argocd get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d

See argocd/README.md for detailed usage.

Flux

Flux provides a lightweight, CLI-focused GitOps solution.

Installation

bash

make install-flux

GitRepository Resource

yaml

apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: GitRepository
metadata:
  name: sample-app
  namespace: flux-system
spec:
  interval: 1m
  url: https://github.com/your-org/your-repo
  ref:
    branch: main

Kustomization Resource

yaml

apiVersion: kustomize.toolkit.fluxcd.io/v1beta2
kind: Kustomization
metadata:
  name: sample-app
  namespace: flux-system
spec:
  interval: 5m
  path: ./kustomize/overlays/staging
  prune: true
  sourceRef:
    kind: GitRepository
    name: sample-app
  targetNamespace: staging

See flux/README.md for detailed usage.

Tool Comparison

Feature	Kustomize	Argo CD	Flux
Role	Configuration	Deployment	Deployment
Interface	CLI	Visual UI	CLI
Architecture	Tool	Centralized	Modular
Best For	Organizing YAML	Visual teams	Platform engineers
Multi-Tenancy	N/A	Built-in SSO	Kubernetes RBAC
Use Case	Write manifests	Deploy with UI	Deploy headless

Remember: Use Kustomize WITH Argo CD or Flux, not instead of them!

See TOOL-COMPARISON.md for detailed comparison.

Integration Examples

Complete GitOps Workflow

Write manifests with Kustomize
Commit to Git repository
Argo CD/Flux detects changes
Automatic deployment to cluster

Multi-Environment Deployment

bash

# Staging deployment
kubectl kustomize kustomize/overlays/staging | kubectl apply -f -

# Production deployment
kubectl kustomize kustomize/overlays/production | kubectl apply -f -

Troubleshooting

Kustomize Build Fails

bash

# Validate kustomization.yaml
kubectl kustomize kustomize/base --dry-run=client

# Check for syntax errors
kubectl kustomize kustomize/overlays/staging

Argo CD Not Syncing

bash

# Check Argo CD pods
kubectl get pods -n argocd

# Check application status
kubectl get application -n argocd

# View Argo CD logs
kubectl logs -n argocd -l app.kubernetes.io/name=argocd-application-controller

Flux Not Deploying

bash

# Check Flux controllers
kubectl get pods -n flux-system

# Check GitRepository status
flux get sources git

# Check Kustomization status
flux get kustomizations

# View Flux logs
kubectl logs -n flux-system -l app=source-controller

Cleanup

Remove All GitOps Tools

bash

# Uninstall everything
make uninstall-all

# Or manually
make uninstall-argocd
make uninstall-flux

Cost Considerations

Estimated Costs

Monthly Cost (if running continuously): ~$20-30

Argo CD: $10-15/month
Flux: $5-10/month
Kustomize: No additional cost (CLI tool)

Cost to Complete (run for 1-2 hours): ~$1-3

Component deployment: Minimal
GitOps operations: Negligible
Monitoring overhead: Included in cluster costs

Cost Optimization

Use Flux for lower overhead (if UI not needed)
Argo CD and Flux are lightweight
Kustomize has no additional cost
Destroy test resources immediately

Next Steps

Immediate Next Actions

Set up Kustomize base and overlays
Choose GitOps tool (Argo CD or Flux)
Configure Git repository connection
Test automated deployment

Continue Your Learning Journey

Next Recommended Lab

Lab 07 - Serverless Operations - Serverless applications

Lab 02: Kubernetes Platform - Deploy to this cluster
Lab 03: CI/CD Pipelines - Integrate with GitOps
Lab 05: Security Automation - Secure GitOps deployments

Additional Resources

Documentation

Learning Resources

Outcome: deployments are now driven by Kustomize and Argo CD/Flux — changes to the cluster go through Git, not kubectl apply.

Next: Lab 07 · Serverless Operations — an event-driven workload outside the cluster.

Navigation: ◀ Lab 05 · Security Automation · All labs · Lab 07 · Serverless Operations ▶

Lab 06 · GitOps Workflows ​

What you build ​

Architecture ​

GitOps Workflow ​

Prerequisites ​

Required Tools ​

AWS Requirements ​

Knowledge Prerequisites ​

Lab Dependencies ​

Quick Start ​

Detailed Setup ​

Step 1: Verify Cluster Access ​

Step 2: Set Up Kustomize ​

Step 3: Choose Your GitOps Tool ​

Step 4: Configure GitOps ​

Project Structure ​

Kustomize ​

Base Configuration ​

Environment Overlays ​

Argo CD ​

Installation ​

Application Definition ​

Accessing the UI ​

Flux ​

Installation ​

GitRepository Resource ​

Kustomization Resource ​

Tool Comparison ​

Integration Examples ​

Complete GitOps Workflow ​

Multi-Environment Deployment ​

Troubleshooting ​

Kustomize Build Fails ​

Argo CD Not Syncing ​

Flux Not Deploying ​

Cleanup ​

Remove All GitOps Tools ​

Cost Considerations ​

Estimated Costs ​

Cost Optimization ​

Next Steps ​

Immediate Next Actions ​

Continue Your Learning Journey ​

Next Recommended Lab ​

Related Labs ​

Additional Resources ​

Documentation ​

Learning Resources ​

Lab 06 · GitOps Workflows

What you build

Architecture

GitOps Workflow

Prerequisites

Required Tools

AWS Requirements

Knowledge Prerequisites

Lab Dependencies

Quick Start

Detailed Setup

Step 1: Verify Cluster Access

Step 2: Set Up Kustomize

Step 3: Choose Your GitOps Tool

Step 4: Configure GitOps

Project Structure

Kustomize

Base Configuration

Environment Overlays

Argo CD

Installation

Application Definition

Accessing the UI

Flux

Installation

GitRepository Resource

Kustomization Resource

Tool Comparison

Integration Examples

Complete GitOps Workflow

Multi-Environment Deployment

Troubleshooting

Kustomize Build Fails

Argo CD Not Syncing

Flux Not Deploying

Cleanup

Remove All GitOps Tools

Cost Considerations

Estimated Costs

Cost Optimization

Next Steps

Immediate Next Actions

Continue Your Learning Journey

Next Recommended Lab

Related Labs

Additional Resources

Documentation

Learning Resources