[Fly.io] Use Fly.io to Deploy Your Application via Dockerfile

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Deploy Your Application via Dockerfile

You already have a project wrapped up in a docker container - https://docs.docker.com/engine/reference/builder/ ? Great! Just deploy that!

The fly launch command detects your Dockerfile and builds it. If you have Docker running locally, it builds it on your machine. If not, it builds it on a Fly build machine. Once your container is built, it’s deployed! Need some extra config? No sweat, we’ve got you covered. Let’s take a look.

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$ fly launch

? App Name (leave blank to use an auto-generated name):
? Select organization: Mark Ericksen (personal)
? Select region: lax (Los Angeles, California (US))
Created app weathered-wave-1020 in organization personal
Wrote config file fly.toml
? Would you like to deploy now? (y/N)

Let fly launch generate an app name for you or pick your own.

Select the Fly.io region - https://fly.io/docs/reference/regions/ to deploy to. It defaults to the one closest to you.

The launch command generates a fly.toml file for your project with the settings. You can deploy right away, or add some config first.

Config First!

Most Dockerfiles expect some configuration settings through ENV. The generated fly.toml file has a place for you to add your custom ENV settings. It’s the [env] block.

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# fly.toml

[env]
  MY_SPECIAL_ENV=some_value
  MAX_PLAYER_COUNT=15

Add whatever values your Dockerfile or container requires.

Sometimes you have secrets that shouldn’t be checked in to git or shared publicly. For those settings, you can set them using fly secrets.

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$ flyctl secrets set MY_SECRET=romance

Secrets are staged for the first deployment

You can list the secrets you’ve already set using fly secrets list

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$ fly secrets list

NAME      DIGEST                           DATE
MY_SECRET b9e37b7b239ee4aefc75352fe3fa6dc6 1m20s ago

The values aren’t display since they are secret!

Deploy Your App

If you didn’t previously deploy the app, you can do that now.

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$ fly deploy

==> Verifying app config
--> Verified app config
==> Building image
==> Creating build context
--> Creating build context done
==> Building image with Docker
--> docker host: 20.10.12 linux x86_64
Sending build context to Docker daemon  13.98MB
...

If you have Docker running locally, it builds it on your machine. If you don’t have Docker running locally, it builds it on a Fly build machine. Once your container is built, it’s deployed!

See Your App

Run fly open to open your deployed app in a browser.

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$ fly open

You’re off and running!

Taking It Further

Lots of applications deployed in a container have some state that they want to keep. Here are a couple resources to check out for ways to do that.

  • Persistent Volumes - https://fly.io/docs/reference/volumes/: You can create persistent volumes that you can mount into your container for reading and writing data that changes but isn’t blown away when you deploy again.

  • Postgres Database: Deploy a Fly Postgres Database. It automatically creates a DATABASE_URL ENV` when you attach it to your app.

Refenrences

[1] Deploy Your Application via Dockerfile - https://fly.io/docs/getting-started/dockerfile/

[2] Deploy app servers close to your users · Fly - https://fly.io/

[3] Hands-on with Fly - https://fly.io/docs/hands-on/start/

[4] Deploy Your Application via Dockerfile - https://fly.io/docs/getting-started/dockerfile/

[5] Volumes - https://fly.io/docs/reference/volumes/

[6] Postgres on Fly - https://fly.io/docs/reference/postgres/#about-postgres-on-fly

[8] docker container - https://docs.docker.com/engine/reference/builder/