Fly.io reference

Quick references for often-used resources like flyctl and fly.toml. Or dig a little deeper into Fly.io capabilities and how they work.

About Fly.io

  • Architecture: A brief overview of how Firecracker VMs, Anycast networking, Fly Proxy, and the backhaul network come together to create Fly.io’s infrastructure.

  • Regions: The regions around the world where we run servers so your apps can run close to your users.

  • Machine migration: How Fly.io automatically migrates your app’s Machines from problematic hosts to healthy hosts.


Reference docs

  • flyctl: The flyctl CLI reference documentation.

  • App Configuration (fly.toml): The settings for configuring your app in the fly.toml configuration file. The app configuration includes how the app is built, its volume mounts, network services, and more.

  • Fly Launch: A deeper dive into how Fly Launch creates and configures new apps.

  • Fly Proxy: Learn about how Fly Proxy routes requests, handles connections, and does load balancing.

  • Fly Proxy autostop/autostart: Learn how Fly Proxy determines excess capacity for an app to shut down or suspend Machines when they’re not needed and start them back up when there’s traffic.


Working with Fly.io

  • Autoscaling: Adjust the number of running or created Fly Machines dynamically.

  • Builders: The different ways you can assemble applications into deployable images for Fly.io.

  • Load Balancing: How Fly Proxy distributes traffic to your application instances based on load, closeness, and concurrency settings.

  • Multiple processes inside a Fly.io app: The different ways to run multiple processes inside a Fly App.