How to Deploy Remix to Fly.io: Step-by-Step Guide

To deploy a Remix app to Fly.io, first install the Fly CLI and create a Fly app with fly launch. Then configure your Dockerfile or use Fly's Node.js builder, and deploy with fly deploy to run your Remix app in the cloud.

Syntax

Deploying Remix to Fly.io involves these main commands and files:

• fly launch: Initializes your Fly.io app and creates config files.
• fly deploy: Uploads and deploys your app to Fly.io servers.
• Dockerfile: Defines how your Remix app is built and run in Fly.io's environment.
• fly.toml: Configuration file generated by Fly CLI to set app settings.

bash

fly launch
fly deploy

# Dockerfile example snippet
FROM node:18-alpine
WORKDIR /app
COPY package.json package-lock.json ./
RUN npm install
COPY . .
RUN npm run build
CMD ["npm", "start"]

Example

This example shows how to deploy a Remix app using Fly.io with a Dockerfile.

It demonstrates creating the Fly app, writing a Dockerfile, and deploying.

bash

# 1. Install Fly CLI and login
curl -L https://fly.io/install.sh | sh
fly auth login

# 2. Initialize Fly app
fly launch --name remix-app --no-deploy

# 3. Create Dockerfile in your Remix project root

# Dockerfile content:
FROM node:18-alpine
WORKDIR /app
COPY package.json package-lock.json ./
RUN npm install
COPY . .
RUN npm run build
EXPOSE 3000
CMD ["npm", "start"]

# 4. Deploy your app
fly deploy

# 5. Open your deployed app
fly open

Output

==> Creating app remix-app
==> Creating fly.toml
==> No deploy flag set, skipping deploy

# After running fly deploy:
==> Building image
==> Pushing image
==> Releasing image
App deployed

# fly open opens your app URL in browser

Common Pitfalls

Common mistakes when deploying Remix to Fly.io include:

• Not creating or misconfiguring the Dockerfile, causing build failures.
• Forgetting to expose the correct port (usually 3000) in the Dockerfile.
• Skipping fly launch or not setting the app name, leading to deployment errors.
• Not running npm run build before starting the app, so Remix server code is missing.

Always check Fly.io logs with fly logs to debug deployment issues.

dockerfile

### Wrong Dockerfile example (missing build step and port)
FROM node:18-alpine
WORKDIR /app
COPY . .
CMD ["npm", "start"]

### Correct Dockerfile example
FROM node:18-alpine
WORKDIR /app
COPY package.json package-lock.json ./
RUN npm install
COPY . .
RUN npm run build
EXPOSE 3000
CMD ["npm", "start"]

Quick Reference

Summary tips for deploying Remix to Fly.io:

• Use fly launch once to create config files.
• Write a Dockerfile that installs dependencies, builds Remix, and exposes port 3000.
• Deploy with fly deploy and check logs with fly logs.
• Ensure your Remix app listens on the port Fly.io expects (usually 3000).
• Use fly open to open your live app in a browser.

Key Takeaways

Run fly launch to initialize your Fly.io app before deploying.

Create a Dockerfile that installs dependencies, builds your Remix app, and exposes port 3000.

Use fly deploy to upload and start your Remix app on Fly.io.

Check deployment logs with fly logs to troubleshoot issues.

Ensure your Remix app listens on the correct port for Fly.io to route traffic properly.