jzaki / bls-wallet-aggregator

Aggregation service for bls-signed transaction data

Consolidated into mono-repo, bls-wallet

BLS Aggregator

Aggregation service for bls-signed transaction data.

Accepts posts of signed transactions and, upon instruction, can aggregate signatures and submit a transaction batch to the configured Verification Gateway.

Installation

Install Deno.

Configuration

cp .env.example .env

Edit values as needed, e.g. private key and contract addresses.

You can also configure multiple environments by appending .<name>, for example you might have:

.env.local
.env.optimistic-kovan

If you don't have a .env, you will need to append --env <name> to all commands.

PostgreSQL

Install, e.g.:

sudo apt update
sudo apt install postgresql postgresql-contrib

Create a user called bls:

$ sudo -u postgres createuser --interactive
Enter name of role to add: bls
Shall the new role be a superuser? (y/n) n
Shall the new role be allowed to create databases? (y/n) n
Shall the new role be allowed to create more new roles? (y/n) n

Set the user's password:

$ sudo -u postgres psql                                                
psql (12.6 (Ubuntu 12.6-0ubuntu0.20.04.1))
Type "help" for help.

postgres=# ALTER USER bls WITH PASSWORD 'generate-a-strong-password';

Create a table called bls_aggregator:

sudo -u postgres createdb bls_aggregator

On Ubuntu (and probably elsewhere), postgres is configured to offer SSL connections but with an invalid certificate. However, the deno driver for postgres doesn't support this.

There are two options here:

1. Set up SSL with a valid certificate (guide).
2. Turn off SSL in postgres (only for development or if you can ensure the connection isn't vulnerable to attack).
   1. View the config location with sudo -u postgres psql -c 'SHOW config_file'.
   2. Turn off ssl in that config.

      -ssl = on
      +ssl = off

   3. Restart postgres sudo systemctl restart postgresql.

Running

Can be run locally or hosted.

./programs/aggregator.ts
# Or if you have a named environment (see configuration section):
# ./programs/aggregator.ts --env <name>

Testing

• launch optimism
• deploy contract script
• run tests

NB each test must use unique address(es). (+ init code)

Development

Environment

This project is written in TypeScript targeting Deno. To get your tools to interpret the code correctly you'll need deno-specific tooling - if you're using VS Code then you should get the Deno Extension.

Programs

The main entry point is located at ./programs/aggregator.ts, but there are other useful utilities in there that call into src, such as ./programs/showTables.ts. Everything in src is library-style code - it provides functions, classes, constants etc, but doesn't do anything on its own if you run it directly.

Testing

Tests are defined in test. Running them directly is a bit verbose because of the deno flags you need:

deno test -j --allow-net --allow-env --allow-read --unstable -- --env local

Instead, ./programs/premerge.ts may be more useful for you. It'll make sure all TypeScript compiles correctly before running anything (in deno it's easy to have broken TypeScript lying around because it only compiles the sources that are actually imported whenever you run something). There's also a bunch of other checking going on. As the name suggests, it's a good idea to make sure this script completes successfully before merging into main.

Notable Components

• src/chain: Should contain all of the contract interactions, exposing more suitable abstractions to the rest of the code. There's still some contract interaction in WalletService and in tests though.
• BlsWallet: Models a BLS smart contract wallet (see BLSWallet.sol).
• app.ts: Runs the app (the aggregator), requiring only a definition of what to do with the events (invoked with console.log by programs/aggregator.ts).
• WalletService: Responsible for submitting aggregations (aka batches) once they have been formed. This was where all the contract interaction was before src/chain. Probably needs a rename and some rethinking.
• TxService: Keeps track of all stored transactions, as well as accepting (or rejecting) them and sending off batches to WalletService.
• TxTable: Abstraction layer over postgres transaction tables, exposing typed functions instead of queries. Handles conversions to and from the field types supported by postgres so that other code can has a uniform js-friendly interface (TransactionData).
• Client: Provides an abstraction over the external HTTP interface so that programs talking to the aggregator can do so via regular js functions with types instead of dealing with raw HTTP. (This should maybe find its way into a separate library - at the moment bls-wallet-extension uses this via ad hoc copy+paste.)

System Diagram

Hosting Guide

1. Configure your server to allow TCP on ports 80 and 443

2. Follow the Installation instructions

3. Install docker and nginx: sudo apt update && sudo apt install docker.io nginx

4. Run ./programs/build.ts

• If you're using a named environment, add --env <name>
• If docker requires sudo, add --sudo-docker

5. Configure log rotation in docker by setting /etc/docker/daemon.json to

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m",
    "max-file": "3"
  }
}

and restart docker sudo systemctl restart docker

6. Load the docker image: sudo docker load <docker-image.tar.gz
7. Run the aggregator:

sudo docker run \
  --name aggregator \
  -d \
  --net=host \
  --restart=unless-stopped \
  aggregator:latest

8. Create /etc/nginx/sites-available/aggregator

server {
  server_name your-domain.org;

  root /home/aggregator/static-content;
  index index.html;

  location / {
    try_files $uri $uri/ @aggregator;
  }

  location @aggregator {
    proxy_pass http://localhost:3000;
  }
}

This allows you to add some static content at /home/aggregator/static-content. Adding static content is optional; requests that don't match static content will be passed to the aggregator.

9. Create a symlink in sites-enabled

ln -s /etc/nginx/sites-available/aggregator /etc/nginx/sites-enabled/aggregator

Reload nginx for config to take effect: sudo nginx -s reload

10. Set up https for your domain by following the instructions at https://certbot.eff.org/lets-encrypt/ubuntufocal-nginx.