paktech-hello

A minimal Flask app demonstrating Scenario 3: GitOps with Argo CD, GitHub, and AKS from the Microsoft Architecture Center.

Architecture

Developer pushes code
        │
        ▼
  GitHub (paktech-hello)
        │
        ▼
  GitHub Actions CI
  ├── Lint (ruff + black)
  ├── Build Docker image
  ├── Push to ACR
  └── Update image tag in paktech-hello-gitops repo
                              │
                              ▼
                    GitHub (paktech-hello-gitops)
                    apps/paktech-hello/deployment.yaml
                              │
                              │  Argo CD polls every 3 min
                              ▼
                    AKS Cluster
                    └── Argo CD detects drift → syncs
                              │
                              ▼
                    paktech-hello namespace
                    └── Flask app pods (2 replicas)
                        └── LoadBalancer service (public IP)

Repositories

Repo	Purpose
paktech-hello	App code, Dockerfile, GitHub Actions CI
paktech-hello-gitops	Kubernetes manifests — source of truth for Argo CD

Project Structure

paktech-hello/
├── app/
│   ├── app.py              # Flask application
│   └── requirements.txt    # Python dependencies
├── Dockerfile              # Multi-stage Docker build
├── terraform/              # Infrastructure as Code
│   ├── main.tf             # AKS + ACR + Argo CD + OIDC
│   ├── variables.tf
│   ├── outputs.tf
│   └── terraform.tfvars.example
└── .github/
    └── workflows/
        └── ci.yml          # Build → Push → Update GitOps repo

Prerequisites

• Azure CLI (az)
• Terraform >= 1.6
• kubectl
• Docker
• GitHub account with two repos created under PakTechLimited:
  • paktech-hello (this repo)
  • paktech-hello-gitops

Deployment Steps

Step 1 — Provision Infrastructure

cd terraform
cp terraform.tfvars.example terraform.tfvars
# Edit terraform.tfvars with your subscription_id

az login
terraform init
terraform plan -var="subscription_id=$(az account show --query id -o tsv)" -out=tfplan
terraform apply tfplan

Step 2 — Add GitHub Secrets

After terraform apply, run:

terraform output argocd_instructions

Add these secrets to github.com/PakTechLimited/paktech-hello → Settings → Secrets:

Secret	Value
AZURE_CLIENT_ID	from terraform output github_actions_client_id
AZURE_TENANT_ID	from terraform output tenant_id
AZURE_SUBSCRIPTION_ID	your subscription ID
ACR_LOGIN_SERVER	from terraform output acr_login_server
ACR_NAME	from terraform output acr_name
GITOPS_PAT	GitHub PAT with repo write scope for paktech-hello-gitops

Step 3 — Connect kubectl to AKS

az aks get-credentials \
  --resource-group paktech-hello-rg-dev \
  --name paktech-hello-aks-dev

Step 4 — Register GitOps Repo with Argo CD

# Port-forward Argo CD UI
kubectl port-forward svc/argocd-server -n argocd 8080:80 &

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

# Login to Argo CD CLI
argocd login localhost:8080 \
  --username admin \
  --password $ARGOCD_PASSWORD \
  --insecure

# Add the GitOps repo (if private — needs a PAT)
argocd repo add https://github.com/PakTechLimited/paktech-hello-gitops \
  --username git \
  --password <YOUR_GITHUB_PAT>

Step 5 — Create the Argo CD Application

kubectl apply -f https://raw.githubusercontent.com/PakTechLimited/paktech-hello-gitops/main/apps/paktech-hello/argocd-app.yaml

Or via Argo CD UI at http://localhost:8080.

Step 6 — Trigger First Deployment

Push any commit to main:

git commit --allow-empty -m "ci: trigger first deployment"
git push

GitHub Actions will:

1. Build the Docker image
2. Push to ACR
3. Update the image tag in paktech-hello-gitops

Argo CD will detect the change within 3 minutes and deploy to AKS.

Step 7 — Access the App

kubectl get svc -n paktech-hello
# Wait for EXTERNAL-IP to be assigned (1-2 minutes)

Open http://<EXTERNAL-IP> in your browser.

GitOps in Action

See Argo CD UI at http://localhost:8080:

# Check sync status
argocd app get paktech-hello

# Manual sync
argocd app sync paktech-hello

# View app history
argocd app history paktech-hello

# Rollback to previous version
argocd app rollback paktech-hello <revision-number>

Cleanup

cd terraform
terraform destroy -var="subscription_id=$(az account show --query id -o tsv)"