CogRPC Implementation in JavaScript

This library implements CogRPC in JavaScript with types included. It offers a CogRPC client and the building blocks to implement a CogRPC server. This documentation assumes familiarity with CogRPC.

Install

@relaycorp/cogrpc can be installed as follows:

npm install @relaycorp/cogrpc

Use

The next section explains how to use this library. You may also want to read the API documentation.

As a client

The first step to use the CogRPC client is to initialize it:

import { CogRPCClient } from '@relaycorp/cogrpc';

const SERVER_URL = 'https://192.168.43.1';
const client = await CogRPCClient.init(SERVER_URL);

You can start delivering and collecting cargo once the client is initialized -- Simply use the client methods deliverCargo() and collectCargo(), respectively.

For example, the following is an overly simplistic version of a courier synchronizing cargo with the public gateway at https://gb.relaycorp.tech:

import { CogRPCClient } from '@relaycorp/cogrpc';
import { Cargo, CargoDeliveryRequest } from '@relaycorp/relaynet-core';
import { promises as fs } from 'fs';

const ROOT_DIR = '/var/cargoes';

async function main(): Promise<void> {
  const gwAddress = 'https://gb.relaycorp.tech';
  const client = await CogRPCClient.init(gwAddress);

  // Deliver cargo
  const outgoingCargoes = retrieveOutgoingCargoes(gwAddress);
  for await (const deliveredCargoPath of client.deliverCargo(outgoingCargoes)) {
    // Delete each cargo as soon as it's delivered
    await fs.unlink(deliveredCargoPath);
  }

  // Collect cargo
  const cca = await fs.readFile(`${ROOT_DIR}/ccas/${gwAddress}`);
  for await (const incomingCargo of client.collectCargo(cca)) {
    let cargo: Cargo;
    try {
      cargo = await Cargo.deserialize(incomingCargo);
      await cargo.validate();
    } catch (error) {
      continue;
    }
    const path = `${ROOT_DIR}/sneakernet-bound/${cargo.recipientAddress}/${cargo.id}`;
    await fs.writeFile(path, incomingCargo);
  }
}

async function* retrieveOutgoingCargoes(
  publicGatewayAddress: string,
): AsyncIterable<CargoDeliveryRequest> {
  const dir = `${ROOT_DIR}/internet-bound/${publicGatewayAddress}`;
  for await (const cargoPath of fs.readdir(dir)) {
    yield { cargo: await fs.readFile(cargoPath), localId: cargoPath };
  }
}

In a server

If you're writing a CogRPC server in a courier or a public gateway, you may want to use the following values exported by this library:

• CargoRelayService, which is the ProtoBuf representation of the service.
• CargoDelivery and CargoDeliveryAck, the interfaces for the data exchanged over gRPC.

Support

If you have any questions or comments, please create an issue on GitHub.

Updates

Releases are automatically published on GitHub and NPM, and the changelog can be found on GitHub. This project uses semantic versioning.