Fly.io Deployment

Deploy ProjectAchilles to Fly.io using Docker Machines with persistent volumes. At ~$8/month, this is the cheapest always-on deployment option.

Architecture

Service	Machine Size	Volume	Public Domain
achilles-backend	shared-2x, 512 MB	1 GB achilles_data	Yes
achilles-frontend	shared-1x, 256 MB	None	Yes

The frontend calls the backend directly via CORS. Both Machines run always-on (auto_stop_machines = 'off') since agents send heartbeats every 60s.

Prerequisites

• Fly.io account
• flyctl CLI: curl -L https://fly.io/install.sh | sh
• Clerk application keys
• Elastic Cloud deployment

Step 1: Create Apps and Volume

flyctl auth login

# Create apps
flyctl apps create achilles-backend --org personal
flyctl apps create achilles-frontend --org personal

# Create persistent volume (must match region in fly.toml)
flyctl volumes create achilles_data --app achilles-backend --region cdg --size 1

Step 2: Set Environment Variables

flyctl secrets set \
  CLERK_PUBLISHABLE_KEY="pk_live_..." \
  CLERK_SECRET_KEY="sk_live_..." \
  SESSION_SECRET="$(openssl rand -base64 32)" \
  ENCRYPTION_SECRET="$(openssl rand -base64 32)" \
  CORS_ORIGIN="https://achilles-frontend.fly.dev" \
  AGENT_SERVER_URL="https://achilles-backend.fly.dev" \
  TESTS_REPO_URL="https://github.com/your-org/f0_library.git" \
  GITHUB_TOKEN="ghp_..." \
  ELASTICSEARCH_CLOUD_ID="..." \
  ELASTICSEARCH_API_KEY="..." \
  --app achilles-backend

flyctl secrets set \
  CLERK_PUBLISHABLE_KEY="pk_live_..." \
  VITE_API_URL="https://achilles-backend.fly.dev" \
  --app achilles-frontend

Step 3: Deploy

cd backend && flyctl deploy --app achilles-backend
cd ../frontend && flyctl deploy --app achilles-frontend

First builds take 3-5 minutes. Subsequent builds reuse cached Docker layers.

Step 4: Verify

curl https://achilles-backend.fly.dev/api/health
# Expected: {"status":"ok","service":"ProjectAchilles",...}

Visit https://achilles-frontend.fly.dev and verify Clerk login works.

Custom Domains

Fly.io uses A/AAAA records (not CNAME like Render/Vercel):

flyctl certs create your-frontend-domain --app achilles-frontend
flyctl certs create your-backend-domain --app achilles-backend

Add the A/AAAA records shown by flyctl certs show to your DNS provider. TLS certificates are auto-provisioned by Let's Encrypt.

Deploying Updates

Fly.io does not auto-deploy from GitHub. Either deploy manually or set up CI/CD:

# .github/workflows/deploy-fly.yml
- uses: superfly/flyctl-actions/setup-flyctl@master
- run: flyctl deploy --app achilles-backend
  working-directory: backend
  env:
    FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}

Useful Commands

flyctl logs --app achilles-backend          # View logs
flyctl ssh console --app achilles-backend   # SSH into Machine
flyctl status --app achilles-backend        # Machine status
flyctl volumes list --app achilles-backend  # List volumes
flyctl apps restart achilles-backend        # Restart

Agent Build from Source

Full Go build support (Docker image includes Go 1.24.3). Set AGENT_REPO_URL and AGENT_REPO_BRANCH.

Cost Estimate

Service	Est. Monthly Cost
Backend (shared-2x, 512 MB)	~$5
Frontend (shared-1x, 256 MB)	~$3
Volume (1 GB)	~$0.15
Total	~$8

Troubleshooting

Frontend shows "502 Bad Gateway" at startup

The nginx config hardcodes Docker Compose hostnames. Set VITE_API_URL on the frontend — docker-entrypoint.sh detects this and removes the proxy blocks.

Volume data not persisting

Verify the volume is attached and in the same region as the Machine:

flyctl volumes list --app achilles-backend

TLS certificate not provisioning

flyctl certs check <domain> --app <app-name>

Verify DNS records point to the correct Fly.io IPs.