WebAssembly for Proxies (AssemblyScript SDK)

This is a friendly fork of https://github.com/Kong/proxy-wasm-assemblyscript-sdk/, mantained to address an incompatibility between the AssemblyScript SDK and the Rust SDK,

It also adds some FastEdge specific functionality.

How to use this SDK

Create a new project:

npm init
npm install --save-dev assemblyscript
npx asinit .

Include "use": "abort=abort_proc_exit" to the asconfig.json file as part of the options passed to asc compiler:

{
  "options": {
    "use": "abort=abort_proc_exit"
  }
}

Add "@gcoredev/proxy-wasm-sdk-as": "^1.0.2" to your dependencies then run npm install.

Hello, World

Copy this into assembly/index.ts:

export * from "@gcoredev/proxy-wasm-sdk-as/assembly/proxy";
import {
  RootContext,
  Context,
  registerRootContext,
  FilterHeadersStatusValues,
  stream_context,
} from "@gcoredev/proxy-wasm-sdk-as/assembly";

class AddHeaderRoot extends RootContext {
  createContext(context_id: u32): Context {
    return new AddHeader(context_id, this);
  }
}

class AddHeader extends Context {
  constructor(context_id: u32, root_context: AddHeaderRoot) {
    super(context_id, root_context);
  }
  onResponseHeaders(a: u32, end_of_stream: bool): FilterHeadersStatusValues {
    const root_context = this.root_context;
    if (root_context.getConfiguration() == "") {
      stream_context.headers.response.add("hello", "world!");
    } else {
      stream_context.headers.response.add(
        "hello",
        root_context.getConfiguration()
      );
    }
    return FilterHeadersStatusValues.Continue;
  }
}

registerRootContext((context_id: u32) => {
  return new AddHeaderRoot(context_id);
}, "add_header");

Build

To build, simply run:

npm run asbuild

build results will be in the build folder. debug.wasm and release.wasm are the compiled file that we will use (you only need one of them, if unsure use release.wasm).

Run

These binaries can then be uploaded and attached to your CDN applications within the FastEdge UI portal.

For some binaries (the above example for instance) you can test localy using envoy.

Please see Envoy.md

Examples

For more examples on how to use this proxy-wasm-sdk-as please see our examples repo