lambda-web

Run Rust web server frameworks on AWS Lambda. Currently, it supports Actix web, axum, Rocket, warp.

Features

Supported web frameworks

• Actix Web 4.0
• axum 0.6
• Rocket 0.5.0-rc.2
• warp 0.3

Supported AWS infrastructure

• API Gateway HTTP API with payload format version 2.0
• API Gateway REST API
• Lambda function URLs

Not supported

• API Gateway HTTP API with payload format version 1.0
• Application Load Balancer (ALB)

Example

Actix Web

Cargo.toml

[[bin]]
name = "bootstrap"path = "src/main.rs"
[dependencies]
lambda-web = { version = "0.2.0", features=["actix4"] }

main.rs

use lambda_web::actix_web::{self, get,App,HttpServer,Responder};use lambda_web::{is_running_on_lambda, run_actix_on_lambda,LambdaError};#[get("/")]asyncfnhello() -> implResponder{format!("Hello")}#[actix_web::main]asyncfnmain() -> Result<(),LambdaError>{let factory = move || {App::new().service(hello)};ifis_running_on_lambda(){// Run on AWS Lambdarun_actix_on_lambda(factory).await?;}else{// Local serverHttpServer::new(factory).bind("127.0.0.2.0080")?
.run().await?;}Ok(())}

axum

Cargo.toml

[[bin]]
name = "bootstrap"path = "src/main.rs"
[dependencies]
lambda-web = { version = "0.2.0", features=["hyper"] }
axum = "0.6"tokio = { version = "1" }

main.rs

use axum::{routing::get,Router};use lambda_web::{is_running_on_lambda, run_hyper_on_lambda,LambdaError};use std::net::SocketAddr;// basic handler that responds with a static stringasyncfnroot() -> &'staticstr{"Hello, World!"}#[tokio::main]asyncfnmain() -> Result<(),LambdaError>{// build our application with a routelet app = Router::new().route("/",get(root));ifis_running_on_lambda(){// Run app on AWS Lambdarun_hyper_on_lambda(app).await?;}else{// Run app on local serverlet addr = SocketAddr::from(([127,0,0,1],8080));
axum::Server::bind(&addr).serve(app.into_make_service()).await?;}Ok(())}

Rocket

Cargo.toml

[[bin]]
name = "bootstrap"path = "src/main.rs"
[dependencies]
lambda-web = { version = "0.2.0", features=["rocket05"] }
rocket = "0.5.0-rc.2"

main.rs

use rocket::{self, get, routes};use lambda_web::{is_running_on_lambda, launch_rocket_on_lambda,LambdaError};#[get("/hello/<name>/<age>")]fnhello(name:&str,age:u8) -> String{format!("Hello, {} year old named {}!", age, name)}#[rocket::main]asyncfnmain() -> Result<(),LambdaError>{let rocket = rocket::build().mount("/",routes![hello]);ifis_running_on_lambda(){// Launch on AWS Lambdalaunch_rocket_on_lambda(rocket).await?;}else{// Launch local serverlet _ = rocket.launch().await?;}Ok(())}

warp

Cargo.toml

[[bin]]
name = "bootstrap"path = "src/main.rs"
[dependencies]
lambda-web = { version = "0.2.0", features=["hyper"] }
warp = "0.3"tokio = { version = "1" }

main.rs

use lambda_web::{is_running_on_lambda, run_hyper_on_lambda,LambdaError};use warp::Filter;#[tokio::main]asyncfnmain() -> Result<(),LambdaError>{// GET /hello/warp => 200 OK with body "Hello, warp!"let hello = warp::path!("hello" / String).map(|name| format!("Hello, {}", name));ifis_running_on_lambda(){// Run on AWS Lambdarun_hyper_on_lambda(warp::service(hello)).await?;}else{// Run local server
warp::serve(hello).run(([127,0,0,1],8080)).await;}Ok(())}

Create deploy ZIP file

As of writing (Nov, 2021), we have two options to run Rust on AWS Lambda: Amazon Linux 2 custom runtime or Docker container image.

I recommend ZIP deploy to Amazon Linux 2 custom runtime (provided.al2) because it's faster cold start time than container image.

To build Amazon Linux 2 compatible binary, see Deploy.md for more details.

Setup AWS Lambda & function URLs

• Create lambda function with provided.al2 custom runtime. Choose "Provide your own bootstrap on Amazon Linux 2" .
• Upload ZIP file described above.
• IAM role, memory settings, etc. are as your demands.
  As sample code above consumes only 30MB of memory, many simple Rust app can fit in 128MB setting.
• Create function URL, then you can call your Lambda function with https://<url-id>.lambda-url.<region>.on.aws
• You can use CloudFront for custom domain.

Setup AWS Lambda & API gateway

Lambda

• Create lambda function with provided.al2 custom runtime. Choose "Provide your own bootstrap on Amazon Linux 2" .
• Upload ZIP file described above.
• IAM role, memory settings, etc. are as your demands.
  As sample code above consumes only 30MB of memory, many simple Rust app can fit in 128MB setting.

API Gateway (HTTP)

• Create HTTP API
• Create single route "$default" and attach Lambda integration. Make sure, payload format version is "2.0"

API Gateway (REST)

• Create REST API
• Create two resources:
  • ANY method on route / and attach Lambda proxy integration.
  • ANY method on route /{proxy+} and attach Lambda proxy integration.
• In settings tab, add */* binary media type.
• Then, deploy API to stage.