NDC Copenhagen 2025 - Hands-On Labs

Prerequisites

• Spin CLI (3.4.0 or newer)
• Rust (1.8.9 or newer) to compile the host
• WebAssembly Composition Tooling (wac)
  • https://github.com/bytecodealliance/wac

Composing With a Custom Transformer

To compose a new proxy with a custom transformer component, use the commands outlined here:

# Assume a obfuscate component has been implement with Rust in ./components/obfuscate
cd components/obfuscate
cargo build --target wasm32-wasip2 --release

cd ../..

cd host
spin build

#Compose the final application
wac plug --plug ./transformers/rust-transformer/target/wasm32-wasip2/release/obfuscate.wasm \
  target/wasm32-wasip2/release/host.wasm \
  -o composed.wasm

You can find examples of transformers in the /transformers directory.

Run the proxy on your machine

Use the spin up command to run the proxy on your local machine.

The-Do-Nothing Proxy

A composed.wasm has been added to the Git repo, to run that "do-nothing" proxy simply execute spin up in the ./host directory