Deploy a Rust Rocket App

Rocket is a web framework for Rust that makes it simple to write fast, type-safe, secure web applications with incredible usability, productivity and performance.

This guide covers how to deploy a Rocket app to Railway in four ways:

One-click deploy from a template.
From a GitHub repository.
Using the CLI.
Using a Dockerfile.

Now, let's create a Rocket app! 🚀

Create a Rocket App

Note: If you already have a Rocket app locally or on GitHub, you can skip this step and go straight to the Deploy Rocket App to Railway.

To create a new Rocket app, ensure that you have Rust installed on your machine.

Run the following command in your terminal to create a new Rust app:

cargo new helloworld --bin

The command creates a new binary-based Cargo project in a helloworld directory.

Next, cd into the directory and add Rocket as a dependency by running the following command:

cargo add rocket

This will add Rocket as a dependency, and you’ll see it listed in your Cargo.toml file.

Modify the Application File

Next, open the app in your IDE and navigate to the src/main.rs file.

Replace the content with the code below:

#[macro_use] 
extern crate rocket;

#[get("/")]
fn index() -> &'static str {
    "Hello world, Rocket!"
}

#[launch]
fn rocket() -> _ {
    rocket::build().mount("/", routes![index])
}

The code above uses the Rocket framework to create a basic web server that responds to HTTP requests. It defines a simple route using the #[get("/")] macro, which tells Rocket to handle GET requests to the root URL (/).

The index() function is the handler for this route and returns a static string, "Hello world, Rocket!", which will be sent as the response when the root URL is accessed.

The #[launch] attribute on the rocket() function marks it as the entry point to launch the application. Inside rocket(), the server is built with rocket::build() and the index route is mounted to the root path / using mount().

When the application runs, it listens for incoming requests and serves the "Hello world, Rocket!" response for requests made to the root URL, demonstrating a simple routing and response mechanism in Rocket.

Run the Rocket App locally

Run the following command in the helloworld directory via the terminal:

cargo run

All the dependencies will be installed and your app will be launched.

Open your browser and go to http://localhost:8000 to see your app.

Deploy the Rocket App to Railway

Railway offers multiple ways to deploy your Rocket app, depending on your setup and preference.

One-Click Deploy from a Template

If you’re looking for the fastest way to get started, the one-click deploy option is ideal.

Click the button below to begin:

We highly recommend that you eject from the template after deployment to create a copy of the repo on your GitHub account.

Note: You can also choose from a variety of Rocket templates created by the community.

Deploy from the CLI

Install the Railway CLI:
- Install the CLI and authenticate it using your Railway account.
Initialize a Railway Project:
- Run the command below in your Rocket app directory.
```
railway init
```
- Follow the prompts to name your project.
- After the project is created, click the provided link to view it in your browser.
Deploy the Application:
- Use the command below to deploy your app:
```
railway up
```
- This command will scan, compress and upload your app's files to Railway. You’ll see real-time deployment logs in your terminal.
Set Up a Public URL:
- Navigate to the Networking section under the Settings tab of your new service.
- Click Generate Domain to create a public URL for your app.
Note: You'll come across a 502 error where your application doesn't respond. We'll fix that in the next step.
Configure Rocket app to accept non-local connections:
- Rocket apps need to be configured to accept external connections by listening on the correct address, which is typically 0.0.0.0. You can easily do this by setting the address through the environment variable. Run the following command to set the Rocket address to 0.0.0.0:
```
railway variables --set "ROCKET_ADDRESS=0.0.0.0"
```
Redeploy the Service:
- Run railway up again to trigger a redeployment of the service.
Verify the Deployment:
- Once the deployment completes, go to View logs to check if the server is running successfully. Access your public URL again and you should see your app working well.

screenshot of the deployed Rocket service

Deploy from a GitHub Repo

To deploy a Rocket app to Railway directly from GitHub, follow the steps below:

Create a New Project on Railway:
- Go to Railway to create a new project.
Deploy from GitHub:
- Select Deploy from GitHub repo and choose your repository.
  - If your Railway account isn’t linked to GitHub yet, you’ll be prompted to do so.
Add Environment Variables:
- Click Add Variables, then add ROCKET_ADDRESS with the value 0.0.0.0. This allows your Rocket app to accept external connections by listening on 0.0.0.0.
Deploy the App:
- Click Deploy to start the deployment process.
- Once the deployed, a Railway service will be created for your app, but it won’t be publicly accessible by default.
Verify the Deployment:
- Once the deployment completes, go to View logs to check if the server is running successfully.
Note: During the deployment process, Railway will automatically detect that it’s a Rust app.
Set Up a Public URL:
- Navigate to the Networking section under the Settings tab of your new service.
- Click Generate Domain to create a public URL for your app.

Use a Dockerfile

Create a Dockerfile in the helloworld or Rocket app's root directory.

Add the content below to the Dockerfile:

FROM lukemathwalker/cargo-chef:latest-rust-1 AS chef

# Create and change to the app directory.
WORKDIR /app

FROM chef AS planner
COPY . ./
RUN cargo chef prepare --recipe-path recipe.json

FROM chef AS builder 
COPY --from=planner /app/recipe.json recipe.json

# Build dependencies - this is the caching Docker layer!
RUN cargo chef cook --release --recipe-path recipe.json

# Build application
COPY . ./
RUN cargo build --release

CMD ["./target/release/helloworld"]