Layer8 Interceptor

This repository contains a Rust implementation of the Layer8 Interceptor. Analogous to https://github.com/globe-and-citizen/layer8-interceptor

At the time of writing this document, it is a 1:1 port of the original implementation. The offering for this is a smaller wasm binary size and potentially better performance.

How To Build

Prerequisites

• Rust Toolchain
• wasm-tooling

  • wasm32-unkown-unknown target:

    rustup target add wasm32-unknown-unknown

  • wasm-bindgen:

    cargo install wasm-bindgen-cli

  • wasm-pack:

    cargo install wasm-pack

Build

We use wasm-pack to build the wasm module for web.

wasm-pack build --target bundler --all-features --release   

[!NOTE]
If you run into cargo:warning=error: unable to create target: 'No available targets are compatible with triple "wasm32-unknown-unknown"' you will need to use a newer version of llvm. Please follow the first two steps from the attached documentation to achieve this. Setup newer llvm/clang.

[!WARNING]
(WARNING: LLVM v 19.x.x has breaking changes. So, you'll need to update but not to v19.x.x. Suggested: v18.1.0. To check your version of llvm on Windows, use the command, $llvm-cov --version or $clang --version)

Running the interceptor with an example

We can use the We've Got Poems example from the original Layer8 Interceptor repository to test our wasm implementation. We've changed the module used to this wasm implementation.

The example can be found in the wgp directory. Navigate to it and follow the README for a trial run.

[!NOTE] The wasm module needs to be bootstrapped to the Vue frontend. Please see vite.config.js for the configuration.

Tests With Code Coverage

To generate code coverage we use cargo-llvm-cov. To install it run:

cargo install cargo-llvm-cov

You can run code coverage by running:

cargo llvm-cov > test-coverage.txt

The result will be in the newly created test-coverage.txt file. This can be used to generate a HTML report or a lcov.info file.

To generate a HTML report run:

cargo llvm-cov --html --open

To generate a lcov.info file run:

cargo llvm-cov --workspace --lcov --output-path lcov.info

The generated lcov.info can be used with IDE tools like coverage gutters to watch code coverage.

Usage With Experimental Features

To use experimental features, you can use the --features experimental flag when building the wasm module.

make build-experimental

Using websockets

To use websockets, we can use our library as so:

import { WebSocket } from 'layer8-interceptor-rs'

// code here...
  async mounted() {
    this.socket = new L8WebSocket();
    await this.socket.init({
      url: "example.com",
      proxy: "l8proxy.com"
    });

    this.socket.onmessage = (event) => {
      this.messages.push({ text: event.data, id: Math.random() });
    };

    this.socket.onopen = () => {
      console.log('Connected to the WebSocket server');
    };

    this.socket.onclose = () => {
      console.log('Disconnected from the WebSocket server');
    };
  },
  methods: {
    sendMessage() {
      this.socket.send(this.message);
      this.message = '';
    },
  },

// other code here...

Check the example for a full example.