Manual script for setting up a GSNv1 relayer

setup-relayer.md

Manual setup for a GSN relayer

⚠️ This setup is only good for GSNv1. Head over to https://docs.opengsn.org for the latest setup for GSNv2.

Install nginx and certbot

sudo add-apt-repository universe
sudo add-apt-repository ppa:certbot/certbot
sudo apt-get update
sudo apt-get install nginx software-properties-common certbot python-certbot-nginx

Create app folder

sudo mkdir -p /app/bin
sudo mkdir -p /app/data
sudo chown -R ubuntu:ubuntu /app

Download relayer bin

curl 'https://github.com/OpenZeppelin/openzeppelin-gsn-helpers/releases/download/v0.1.4/gsn-relay-linux-amd64' -o /app/bin/RelayHttpServer -L -s
chmod a+x /app/bin/RelayHttpServer

Get certificate and cron it

sudo certbot certonly --nginx
sudo echo "/usr/bin/certbot renew --quiet" > /etc/cron.monthly/certbot

Config nginx

cd /etc/nginx
sudo rm sites-enabled/default

/etc/nginx/sites-available/relayer

log_format postdata escape=json '$remote_addr - $remote_user [$time_local] '
                        '"$request" $status $bytes_sent '
                        '"$http_referer" "$http_user_agent" "$request_body"';

server {
  listen 80;
  server_name example.com;
  
  location ~ /.well-known {
    root /var/www/html;
    allow all;
  }

  location / {
    return 301 https://$server_name$request_uri;
  } 
}

server {
  listen 443 ssl;
  server_name example.com;

  ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;

  location / {
    access_log /var/log/nginx/access.log postdata;

    proxy_pass http://localhost:8091;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_cache_bypass $http_upgrade;
  }
}

Enable new site

cd sites-enabled
sudo ln -ns ../sites-available/relayer
sudo nginx -s reload

Setup environment

/app/env

URL=https://example.com
LOCAL_PORT=8091
WORKDIR=/app/data
NODE_URL=https://NETWORK.infura.io/v3/INFURATOKEN
RELAY_HUB=RELAY_HUB_ADDRESS
GAS_PRICE_PERCENT=0

Configure service on systemd

/etc/sytemd/system/relayer.service

[Unit]
Description=GSN relayer
StartLimitIntervalSec=300

[Service]
User=ubuntu
Group=ubuntu
Type=simple
WorkingDirectory=/app/
EnvironmentFile=/app/env
ExecStart=/app/bin/RelayHttpServer -Url ${URL} -Port ${LOCAL_PORT} -Workdir ${WORKDIR} -EthereumNodeUrl ${NODE_URL} -RelayHubAddress ${RELAY_HUB} -GasPricePercent ${GAS_PRICE_PERCENT}
StandardOutput=journal
StandardError=journal
Restart=on-failure
RestartSec=30
StartLimitBurst=5

[Install]
WantedBy=default.target

Start service

sudo systemctl daemon-reload
sudo systemctl enable relayer
sudo systemctl start relayer

Test it (from local workstation)

curl 'https://example.com/getaddr'

Fund it (from local workstation)

./scripts/fundrelay.js RELAY_HUB_ADDRESS 'https://example.com' 0 PROVIDER_URL

Does something occur where the gas price increases cumulatively as a percentage?

I set the GAS_PRICE_PERCENT to 2, most of my tests pass with a 1.02 Gwei gas price (I am using 1 Gwei as the base gas price), but suddenly somehow I am getting an error:

requires a minimum gas price of 1040400000 which is over this transaction gas price (1020000000)

Did it just do a cumulative 2% on top of 2%? How would this occur? Did I miss something in the docs?

Looking at the logs it goes from

Apr 09 17:30:17 ip-172-31-37-60 RelayHttpServer[1585]: 2020/04/09 17:30:17 RelayHttpServer.go:323: Relay funded. Balance: 3183087823550000000
Apr 09 17:30:17 ip-172-31-37-60 RelayHttpServer[1585]: 2020/04/09 17:30:17 RelayHttpServer.go:278: GasPrice: 1020000000
Apr 09 17:31:05 ip-172-31-37-60 RelayHttpServer[1585]: 2020/04/09 17:31:05 RelayHttpServer.go:107: Relay received gasPrice:: 1020000000
Apr 09 17:31:17 ip-172-31-37-60 RelayHttpServer[1585]: 2020/04/09 17:31:17 RelayHttpServer.go:323: Relay funded. Balance: 3182669993810000000
Apr 09 17:31:17 ip-172-31-37-60 RelayHttpServer[1585]: 2020/04/09 17:31:17 RelayHttpServer.go:278: GasPrice: 1040400000

Note that this script is good for GSN v1 only.
The latest relayer setup documented in https://docs.opengsn.org, and its much simpler, as it uses docker to bring it up.

Just updated the gist to mention that it's for GSNv1, thanks Dror!