hyperlight-wasm sockets example

This is a minimal example of a Hyperlight-Wasm host application. It implements just enough of the wasi:sockets UDP api (in an unfortunately blocking fashion) to run the echo sample server.

Prerequisites

1. Rust, including the x86_64-unknown-none target (which may be installed via e.g. rustup target add x86_64-unknown-none)
2. A C compiler
3. wasm-tools
4. If you are fetching the sample binary from an OCI registry, wkg.

Building

Compile the WIT and set the environment variables used when building (both the host and the guest):

wasm-tools component wit hyperlight.wit -w -o hyperlight-world.wasm
export HYPERLIGHT_WASM_WORLD=$PWD/hyperlight-world.wasm

Build:

cargo build

Running

Get an echo.wasm from the sample repo, either by building it or by fetching it from the OCI registry (wkg oci pull ghcr.io/hyperlight-dev/wasm-udp-echo-sample/udp-echo-server:latest -o echo.wasm).

AOT compile it:

cargo install --git https://github.com/hyperlight-dev/hyperlight-wasm hyperlight-wasm-aot
hyperlight-wasm-aot compile --component echo.wasm echo.bin

You can then run the server:

cargo run # or target/debug/echo

This will not produce any output on stdout, and should wait forever to receive UDP packets on 127.0.0.1:8080.

Testing

In another shell:

Linux

nc -u 127.0.0.1 8080

When using interactively, due to line-buffering, you will likely need to send an entire line to nc before receiving a response.

Windows

Windows does not have a native nc command, however we can use a PowerShell function to achieve the same result:

# Create a PowerShell function to send UDP messages
. ./scripts/Send-UDPMessage.ps1
# Run the function to send a message
Send-UDPMessage -IPAddress "127.0.0.1" -Port 8080