imbolc / tower-sessions

🥠 Sessions as a `tower` and `axum` middleware.

tower-sessions

🥠 Sessions as a `tower` and `axum` middleware.

🎨 Overview

This crate provides sessions, key-value pairs associated with a site visitor, as a tower middleware.

It offers:

• Pluggable Storage Backends: Bring your own backend simply by implementing the SessionStore trait, fully decoupling sessions from their storage.
• Minimal Overhead: Sessions are only loaded from their backing stores when they're actually used and only in e.g. the handler they're used in. That means this middleware can be installed anywhere in your route graph with minimal overhead.
• An axum Extractor for Session: Applications built with axum can use Session as an extractor directly in their handlers. This makes using sessions as easy as including Session in your handler.
• Common Backends Out-of-the-Box: RedisStore, SQLx (SqliteStore, PostgresStore, MySqlStore), and MongoDBStore stores are available via their respective feature flags.
• Simple Key-Value Interface: Sessions offer a key-value interface that supports native Rust types. So long as these types are Serialize and can be converted to JSON, it's straightforward to insert, get, and remove any value.
• Strongly-Typed Sessions: Strong typing guarantees are easy to layer on top of this foundational key-value interface.

This crate's session implementation is inspired by the Django sessions middleware and it provides a transliteration of those semantics.

User session management

To facilitate authentication and authorization, we've built axum-login on top of this crate. Please check it out if you're looking for a generalized auth solution.

📦 Install

To use the crate in your project, add the following to your Cargo.toml file:

[dependencies]
tower-sessions = "0.8.2"

🤸 Usage

axum Example

use std::net::SocketAddr;

use axum::{
    error_handling::HandleErrorLayer, response::IntoResponse, routing::get, BoxError, Router,
};
use http::StatusCode;
use serde::{Deserialize, Serialize};
use time::Duration;
use tower::ServiceBuilder;
use tower_sessions::{Expiry, MemoryStore, Session, SessionManagerLayer};

const COUNTER_KEY: &str = "counter";

#[derive(Default, Deserialize, Serialize)]
struct Counter(usize);

#[tokio::main]
async fn main() {
    let session_store = MemoryStore::default();
    let session_service = ServiceBuilder::new()
        .layer(HandleErrorLayer::new(|_: BoxError| async {
            StatusCode::BAD_REQUEST
        }))
        .layer(
            SessionManagerLayer::new(session_store)
                .with_secure(false)
                .with_expiry(Expiry::OnInactivity(Duration::seconds(10))),
        );

    let app = Router::new()
        .route("/", get(handler))
        .layer(session_service);

    let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
    let listener = tokio::net::TcpListener::bind(&addr).await.unwrap();
    axum::serve(listener, app.into_make_service())
        .await
        .unwrap();
}

async fn handler(session: Session) -> impl IntoResponse {
    let counter: Counter = session.get(COUNTER_KEY).await.unwrap().unwrap_or_default();
    session.insert(COUNTER_KEY, counter.0 + 1).await.unwrap();
    format!("Current count: {}", counter.0)
}

You can find this example as well as other example projects in the example directory.

Note

See the crate documentation for more usage information.

🦺 Safety

This crate uses #![forbid(unsafe_code)] to ensure everything is implemented in 100% safe Rust.

🛟 Getting Help

We've put together a number of examples to help get you started. You're also welcome to open a discussion and ask additional questions you might have.

👯 Contributing

We appreciate all kinds of contributions, thank you!