Fly.io Deployment

Deploy Django Keel projects globally with Fly.io's edge network.

Overview

Fly.io runs your application close to users worldwide with:

• Global edge deployment - Deploy to 30+ regions
• Automatic HTTPS - Free SSL certificates
• PostgreSQL included - Managed Postgres clusters
• Redis included - Managed Redis
• Free tier - Generous free allowance
• Near-instant deploys - Deploy in seconds

Prerequisites

• Fly.io account (free tier available)
• Fly CLI installed
• deployment_targets: [flyio] selected during generation

Installation

Install Fly CLI

# macOS
brew install flyctl

# Linux
curl -L https://fly.io/install.sh | sh

# Windows
powershell -Command "iwr https://fly.io/install.ps1 -useb | iex"

Authenticate

fly auth login

Quick Start

1. Launch Application

From your project directory:

fly launch

Fly.io will: 1. Detect your Django app 2. Generate fly.toml configuration 3. Prompt for app name and region 4. Create PostgreSQL database (optional) 5. Create Redis instance (optional)

2. Configure fly.toml

Generated fly.toml:

app = "your-app-name"
primary_region = "sjc"  # San Jose

[build]
  builder = "paketobuildpacks/builder:base"

[env]
  PORT = "8000"
  DJANGO_SETTINGS_MODULE = "config.settings.prod"

[[services]]
  internal_port = 8000
  protocol = "tcp"

  [[services.ports]]
    port = 80
    handlers = ["http"]

  [[services.ports]]
    port = 443
    handlers = ["tls", "http"]

  [[services.http_checks]]
    interval = "10s"
    timeout = "2s"
    grace_period = "5s"
    method = "GET"
    path = "/health/"

3. Set Secrets

# Required
fly secrets set DJANGO_SECRET_KEY=$(python -c 'from django.core.management.utils import get_random_secret_key; print(get_random_secret_key())')

fly secrets set DEBUG=False
fly secrets set ALLOWED_HOSTS=your-app.fly.dev

# If using AWS S3
fly secrets set AWS_ACCESS_KEY_ID=your-key
fly secrets set AWS_SECRET_ACCESS_KEY=your-secret
fly secrets set AWS_STORAGE_BUCKET_NAME=your-bucket

# If using Sentry
fly secrets set SENTRY_DSN=your-sentry-dsn

# If using Stripe
fly secrets set STRIPE_PUBLIC_KEY=your-public-key
fly secrets set STRIPE_SECRET_KEY=your-secret-key

4. Deploy

fly deploy

Your app will be live at https://your-app.fly.dev

Database Setup

Create PostgreSQL

fly postgres create

Options: - Name: your-app-db - Region: Same as your app - Configuration: Development (1GB RAM, 10GB disk)

Attach Database

fly postgres attach your-app-db

This sets the DATABASE_URL secret automatically.

Create Redis

fly redis create

Options: - Plan: Free (256MB) - Region: Same as your app

Attach Redis

fly redis attach your-redis

This sets the REDIS_URL secret automatically.

Multi-Region Deployment

Deploy to multiple regions for low latency worldwide:

# Add regions
fly regions add ams  # Amsterdam
fly regions add gru  # São Paulo
fly regions add syd  # Sydney

# Scale to 2 machines per region
fly scale count 2

Fly.io automatically routes users to the nearest region.

Adding Background Workers

Celery Worker

Create fly.worker.toml:

app = "your-app-worker"

[build]
  builder = "paketobuildpacks/builder:base"

[deploy]
  release_command = "python manage.py migrate"

[[services]]
  internal_port = 8080
  protocol = "tcp"

Add Procfile for worker:

worker: celery -A config worker -l info

Deploy worker:

fly deploy -c fly.worker.toml

Celery Beat

Similar setup for scheduled tasks:

beat: celery -A config beat -l info

Volumes for Persistent Storage

If not using S3:

# Create volume
fly volumes create data --size 10  # 10GB

# Update fly.toml
[[mounts]]
  source = "data"
  destination = "/data"

Update Django settings:

MEDIA_ROOT = "/data/media"

Custom Domains

Add Domain

fly certs create yourdomain.com
fly certs create www.yourdomain.com

Configure DNS

Add records to your DNS provider:

A     @     66.241.124.123  # Fly.io IP (check dashboard)
AAAA  @     2a09:8280:1::1  # IPv6
CNAME www   your-app.fly.dev

Fly.io automatically provisions SSL certificates.

Monitoring

View Logs

# Real-time logs
fly logs

# Last 100 lines
fly logs --lines 100

Metrics

# Dashboard
fly dashboard

# CLI metrics
fly status
fly vm status

Monitoring Dashboard

Access at: https://fly.io/apps/your-app/monitoring

• Request rate
• Response time
• Error rate
• CPU/Memory usage

Scaling

Vertical Scaling

# List available VM sizes
fly platform vm-sizes

# Scale to shared-cpu-2x (2 CPU, 4GB RAM)
fly scale vm shared-cpu-2x

VM Sizes: - shared-cpu-1x: 1 CPU, 256MB RAM (free tier) - shared-cpu-2x: 2 CPU, 4GB RAM - dedicated-cpu-1x: 1 vCPU, 2GB RAM - dedicated-cpu-2x: 2 vCPU, 4GB RAM

Horizontal Scaling

# Scale to 3 instances
fly scale count 3

# Scale per region
fly scale count 2 --region sjc
fly scale count 2 --region ams

Auto-scaling

# fly.toml
[[services]]
  internal_port = 8000

  [[services.autoscaling]]
    min_instances = 2
    max_instances = 10

Health Checks

Fly.io uses your /health/ endpoint:

[[services.http_checks]]
  interval = "10s"
  timeout = "2s"
  grace_period = "5s"
  method = "GET"
  path = "/health/"

Django Keel provides this endpoint by default.

Zero-Downtime Deployments

Fly.io handles this automatically:

1. Deploys new version
2. Waits for health checks to pass
3. Routes traffic to new version
4. Terminates old version

Troubleshooting

Build Fails

Error: "No Dockerfile found"

# Fly.io expects Dockerfile
# Django Keel provides one
ls Dockerfile  # Verify it exists

Error: "requirements.txt not found"

# For uv projects, create requirements.txt
uv pip compile pyproject.toml -o requirements.txt

Database Connection

Error: "could not connect to database"

# Check DATABASE_URL is set
fly secrets list | grep DATABASE

# Test connection
fly ssh console
python manage.py dbshell

Memory Issues

Error: "OOMKilled"

# Check memory usage
fly vm status

# Scale up
fly scale vm shared-cpu-2x  # 4GB RAM

SSL Certificate Issues

Error: "certificate verification failed"

# Check certificate status
fly certs show yourdomain.com

# Recreate certificate
fly certs remove yourdomain.com
fly certs create yourdomain.com

Cost Optimization

Free Tier Limits

• 3 shared-cpu-1x VMs (256MB RAM each)
• 3GB PostgreSQL storage
• 160GB outbound transfer
• Free HTTPS certificates

Tips

1. Use shared-cpu for dev/staging
2. Auto-scale down during low traffic
3. Optimize images - Reduce Docker image size
4. Use volumes instead of S3 for small files
5. Monitor usage - Set billing alerts

Production Checklist

• [ ] Set DEBUG=False
• [ ] Configure ALLOWED_HOSTS with your domain
• [ ] Set strong DJANGO_SECRET_KEY
• [ ] Enable Sentry for error tracking
• [ ] Set up database backups
• [ ] Configure custom domain with SSL
• [ ] Test Celery workers (if using)
• [ ] Configure auto-scaling
• [ ] Set up monitoring alerts
• [ ] Enable database replication for critical apps

Comparison with Other Platforms

Feature	Fly.io	Render	Heroku
Regions	30+	7	2 (US/EU)
Free Tier	3 VMs, 3GB DB	750 hrs/month	No free tier
Auto-scaling	✅ Yes	✅ Yes	✅ Yes
SSL	✅ Free	✅ Free	✅ Free
Pricing	$1.94+/month	$7+/month	$5-$25+/month

Best Practices

1. Deploy to multiple regions - Low latency worldwide
2. Use volumes for persistent data (if not using S3)
3. Monitor health checks - Ensure endpoints respond
4. Enable auto-scaling - Handle traffic spikes
5. Regular backups - Snapshot PostgreSQL regularly
6. Use Fly CLI - Faster than web dashboard
7. Keep fly.toml in version control

Further Reading

• Fly.io Documentation
• Fly.io Pricing
• Fly.io CLI Reference

Support

• Community Forum: community.fly.io
• Status: status.fly.io