Fly.io Production Checklist

Overview

Fly.io runs applications on edge infrastructure across 30+ regions with Machines, Volumes, and managed Postgres. A production deployment requires multi-region redundancy, proper secret management, health checks, and rollback procedures. Misconfigured auto-scaling means cold starts; missing volume backups mean data loss. This checklist ensures your Fly.io app is production-hardened.

Authentication & Secrets

• FLY_API_TOKEN stored in CI secrets (never in fly.toml or source)
• All app secrets set via fly secrets (not [env] block)
• Deploy tokens scoped per app (not org-wide personal tokens)
• Key rotation scheduled (quarterly, or after team changes)
• No hardcoded secrets in Dockerfile or codebase

API Integration

• Production base URL: app deployed to https://<app>.fly.dev
• force_https = true in fly.toml http_service
• Custom domain with TLS certificate active and auto-renewing
• min_machines_running = 1 to avoid cold starts
• Machines deployed in 2+ regions for redundancy
• Concurrency limits tuned (soft_limit/hard_limit per workload)
• Volumes backed up if using persistent storage

Error Handling & Resilience

• Health check endpoint configured with appropriate grace period
• Graceful shutdown handles SIGTERM within 10s window
• Auto-stop/auto-start configured for cost optimization
• Postgres standby replica provisioned for database apps
• Rollback procedure tested: fly releases rollback <N>
• Dockerfile builds and runs identically local vs deployed

Monitoring & Alerting

• fly logs streaming configured for centralized logging
• Machine health monitored via fly machine status
• Platform status checked: https://status.flyio.net
• Alert on health check failures across any region
• VM resource utilization tracked (fly scale show)

Validation Script

async function checkFlyioReadiness(): Promise<void> {
  const checks: { name: string; pass: boolean; detail: string }[] = [];
  // Fly.io API connectivity
  try {
    const res = await fetch('https://api.machines.dev/v1/apps', {
      headers: { Authorization: `Bearer ${process.env.FLY_API_TOKEN}` },
    });
    checks.push({ name: 'Fly API', pass: res.ok, detail: res.ok ? 'Connected' : `HTTP ${res.status}` });
  } catch (e: any) { checks.push({ name: 'Fly API', pass: false, detail: e.message }); }
  // Token present
  checks.push({ name: 'API Token Set', pass: !!process.env.FLY_API_TOKEN, detail: process.env.FLY_API_TOKEN ? 'Present' : 'MISSING' });
  // Platform status
  try {
    const res = await fetch('https://status.flyio.net/api/v2/status.json');
    const data = await res.json();
    const status = data?.status?.indicator || 'unknown';
    checks.push({ name: 'Platform Status', pass: status === 'none', detail: status === 'none' ? 'Operational' : status });
  } catch (e: any) { checks.push({ name: 'Platform Status', pass: false, detail: e.message }); }
  for (const c of checks) console.log(`[${c.pass ? 'PASS' : 'FAIL'}] ${c.name}: ${c.detail}`);
}
checkFlyioReadiness();

Error Handling

Check	Risk if Skipped	Priority
Multi-region deployment	Single region outage = full downtime	P1
Volume backups	Data loss on machine replacement	P1
Health check config	Dead machines receive traffic	P2
SIGTERM handling	Dropped requests during deploys	P2
Rollback procedure	Stuck on broken release	P3

Resources

• Fly.io Production Checklist
• Fly.io Status

Next Steps

See flyio-security-basics for network policies and secret management.