Multiplayer Sliders - a Fullstack Demo

Technologies used

• Rust's great wasm and wasi support
• Lunatic as a runtime
• Submillisecond for http and websockets
• Sycamore frontend in pure Rust
• Trunk as a bundler

What is it?

this application synchronizes sliders across clients, open it in several tabs or several browsers to see synchronization

this is mainly built to showcase how a full stack rust application could be made

How to run

make sure you have a working cargo installation and wasm32 toolchain

rustup update
rustup target add wasm32-wasi wasm32-unknown-unknown

Install Dependencies

# watch for changes
cargo install cargo-watch
# trunk bundles wasm for browsers and acts as devserver
cargo install --locked trunk
# lunatic runs the resulting wasi code of the server
cargo install lunatic-runtime

run watchers for both frontend and backend

this is how you probably should run the server during development.

backend will run the actual webserver with the websocket

# in first terminal
./watch_backend.sh

Frontend (served by trunk) is the frontend devserver which comes with hot reloading, which is why this setup might be better

# in second terminal
./watch_frontend.sh

both have an optional --release parameter if you want to test the release build

http://localhost:8080 is the frontend server

http://localhost:3000 is the actual server

both should be able to handle clients but the 3000 one doesn't have hot reloading

Running a single watcher

# debug build for everyday development
cargo watch -s "trunk build" -s "cargo run"
# alternatively, release build for testing performance
cargo watch -s "trunk build --release" -s "cargo run --release"

this watcher will watch for any changes, rebuild the frontend and then the backend and run the backend server. Only port 3000 will be oben with this setup

Release Build

you can compile a release build by running trunk build --release && cargo build --release or alternatively ./build_release.sh.

The resulting binary will be in target/wasm32-wasi/release/backend.wasm, to run the server you need to call lunatic backend.wasm

The server wasm is self-contained, it includes the frontend statically baked into the binary and serves those files from memory. This means that you will only need the lunatic binary and the backend.wasm file for deployments