Launch a New App on Fly.io
Fly Launch helps you configure and orchestrate your app.
To create a brand new app on Fly.io, run this command from the source directory of your project:
fly launch
If you’re in a hurry to try your first launch, we have a condensed Hands-on that launches a super-simple demo app. Or check out our language- and framework-specific launch guides.
Ingredients for a successful fly launch
Here are the components of a successful launch, ready for the first deployment:
- A way to get a Docker image that we can use to get your app running on a Machine.
- A
fly.toml
file, created byfly launch
or provided by you, for your app’s Fly.io-specific configuration. - Optional platform resources such as public IP addresses, Fly Volumes, app secrets, Fly Postgres clusters, and integrated resources like Upstash for Redis.
Framework launch scanners
Depending on your project, fly launch
may be able to look at your app’s source code and get through that ingredient list, straight to a ready-to-deploy Fly App. This is most likely to work for frameworks on which Fly.io has people specializing full time. Right now that’s Elixir/Phoenix, Laravel, Rails, and Django, but we also have launch guides for other languages and frameworks.
Our best scanners furnish a Dockerfile from which your app’s image will be built. Some of our terrible older scanners may invoke buildpacks, which tend to be slow and brittle.
Running fly launch
in a directory containing a working Django app (it happens to be the one from our Django getting-started example):
fly launch
Scanning source code
Detected a Django app
Creating app in /flyio/hello-django
We're about to launch your Django app on Fly.io. Here's what you're getting:
Organization: MyName (fly launch defaults to the personal org)
Name: hello-django (derived from your directory name)
Region: Amsterdam, Netherlands (this is the fastest region for you)
App Machines: shared-cpu-1x, 1GB RAM (most apps need about 1GB of RAM)
Postgres: <none> (not requested)
Redis: <none> (not requested)
? Do you want to tweak these settings before proceeding? Yes
...
The flyctl Django scanner has taken ownership of the launch. You can tweak the basic settings on the Fly Launch web page and then run ‘fly deploy’ to deploy the new app. Visit our Django guide to see how that story will end. (Spoiler: it has a happy ending.)
Custom launch
You can nudge fly launch
to better suit your project.
Point to an image or use a Dockerfile to build
Tell fly launch
how you want to get the Docker image for your app, using either the --image
or --dockerfile
option, or by catching the Dockerfile launch scanner’s attention with the presence of a Dockerfile in your project source directory. The Dockerfile scanner doesn’t do a lot of configuration, but it prevents other scanners from taking over.
The actual Docker image build (or image pull) for a Fly App takes place during deployment. fly launch
sets the stage by recording how to build, or get, the image, and both the first and all later deploys use that information.
Customize the configuration file
You can provide your own fly.toml
and fly launch
will offer to copy that configuration to a new app. fly.toml
sets a starting point for the app configuration, and in some cases a framework launch scanner might overwrite parts of it.
There are also a number of other options you can use to exert control over fly launch
.
If fly launch
doesn’t have a scanner that can set up your app automatically, it will still initialize a new Fly App in your Fly.io organization and provide you with a default app configuration that’s a reasonable starting point for a simple web app.
You can also perform an entirely manual “launch”, skipping all the launch scanners and full-service resource provisioning, using fly apps create
, a hand-crafted (or copied) fly.toml
, and step-by-step resource provisioning, followed by fly deploy
.
After fly launch
If you’ve run fly launch
but haven’t deploy yet (hint: you can do this with fly launch --no-deploy
), or you deployed but want to make changes, then you can:
- change your configuration
- update your app source
- change or provision platform resources such as public IP addresses, Fly Volumes, app secrets, Fly Postgres clusters, or integrated resources like Upstash for Redis
And then deploy (or redeploy) with fly deploy
.
After you deploy your app:
- Check up on it using one or more of the techniques in Get Information About an App.
- Get ready to go to production, read up on app availability and resiliency features, and learn how to scale the number of Machines or scale Machine CPU and RAM.
- Go deeper and do even more, at a lower level, with Machines.