A complete 3-tier web application with FastAPI backend, Streamlit frontend, and PostgreSQL database, featuring automated CI/CD pipeline using Docker, Kubernetes, Helm, GitHub Actions, and ArgoCD.
architecture-beta
group fs(cloud)[3 Tier Architecture]
group ui(internet)[Frontend] in fs
group api(internet)[Backend] in fs
service client(server)[Streamlit] in ui
service db(database)[PostgreSQL] in api
service server(server)[FastAPI] in api
client:R <--> L:server
db:L <--> R:server
.
├── .github/workflows/main.yaml # CI/CD Pipeline
├── app/ # FastAPI Application
├── client/ # Streamlit Application
├── helm/ # Helm Charts
├── kubernetes/ # K8s Manifests
├── docker-compose.yml # Local Development
├── Dockerfile.server # API Docker Image
├── Dockerfile.client # UI Docker Image
├── argocd-application.yaml # ArgoCD Application
└── pyproject.toml # Python Dependencies
- Install UV (if not already installed):
# macOS using Homebrew (recommended) brew install uv # macOS/Linux using installer curl -LsSf https://astral.sh/uv/install.sh | sh # Windows powershell -c "irm https://astral.sh/uv/install.ps1 | iex" # Using pip pip install uv
- Setting up UV (Python's Package Manager):
# Initialize UV project uv init --name n-tier --app # Create virtual environment uv venv --python 3.13 # Activate environment (Linux/macOS) source .venv/bin/activate # Install dependencies uv sync
- Run The Application locally:
- Run API(FastAPI)
uv run uvicorn app.main:app --reload --host 0.0.0.0 --port 8000
- Run Streamlit application
uv run streamlit run main.py
- Run API(FastAPI)
# Build FastAPI server image
docker build -f Dockerfile.server -t <dockerhub-user-name>/fastapi-server:latest .
# Build Streamlit client image
docker build -f Dockerfile.client -t <dockerhub-user-name>/streamlit-client:latest .# Login to DockerHub
docker login
# Push images
docker push <dockerhub-user-name>/fastapi-server:latest
docker push <dockerhub-user-name>/streamlit-client:latest# Start application stack
docker compose up -d
# View logs
docker compose logs -f
# Stop and cleanup
docker compose downAccess Points:
- Frontend: http://localhost:8501
- API: http://localhost:8000
- PgAdmin: http://localhost:5050
# Create namespace
kubectl apply -f kubernetes/namespace.yaml
# Deploy all services
kubectl apply -f kubernetes/
# Check deployment status
kubectl get pods -n fastapi-app
kubectl get services -n fastapi-app
# Port forward for local access
kubectl port-forward -n fastapi-app svc/client-service 8501:8501
kubectl port-forward -n fastapi-app svc/api-service 8000:8000# Delete all resources
kubectl delete -f kubernetes/
# Delete namespace
kubectl delete namespace fastapi-app# Install application
helm install n-tier-app ./helm
# Upgrade deployment
helm upgrade n-tier-app ./helm
# Check status
helm status n-tier-app
kubectl get pods -n fastapi-app# Uninstall Helm release
helm uninstall n-tier-app
# Delete namespace if needed
kubectl delete namespace fastapi-app# Create ArgoCD namespace
kubectl create namespace argocd
# Install ArgoCD
kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml
# Wait for pods to be ready
kubectl wait --for=condition=available --timeout=300s deployment/argocd-server -n argocd# Port forward ArgoCD server
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 -dArgoCD Access: https://localhost:8080
- Username: admin
- Password: (from command above)
# Apply ArgoCD application
kubectl apply -f argocd-application.yaml
# Sync application
argocd app sync test-three-tier-app# Delete application
kubectl delete -f argocd-application.yaml
# Uninstall ArgoCD
kubectl delete -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml
kubectl delete namespace argocd-
Continuous Integration:
- Automated Docker image builds
- Automatic tagging with commit SHA
- DockerHub registry push
- Automatic Helm values update
-
Continuous Deployment:
- GitOps approach with ArgoCD
- Auto Sync with Updated Helm values
- Self-healing deployments
- Rollback capabilities
- Triggers on push to
mainbranch - Builds both FastAPI and Streamlit images
- Updates Helm chart with new image tags
- ArgoCD automatically syncs changes to cluster
Configure these secrets in GitHub repository settings:
DOCKERHUB_USRNAME=your_dockerhub_username
DOCKERHUB_PSWD=your_dockerhub_password
- Frontend: Streamlit
- Backend: FastAPI
- Database: PostgreSQL
- Containerization: Docker
- Orchestration: Kubernetes
- Package Management: Helm
- CI/CD: GitHub Actions
- GitOps: ArgoCD
- Local K8s: OrbStack
- Local Development: Use UV for dependency management
- Testing: Docker Compose for integration testing
- Deployment: Kubernetes with Helm charts
- Production: Automated CI/CD with ArgoCD
# Check application logs
kubectl logs -f deployment/api-deployment -n fastapi-app
kubectl logs -f deployment/client-deployment -n fastapi-app
# Check ArgoCD application status
kubectl get applications -n argocd
argocd app get test-three-tier-app
# Monitor resource usage
kubectl top pods -n fastapi-appNote: Ensure OrbStack or another local Kubernetes solution is running before executing Kubernetes commands.