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Relayer
Running a Relayer
Running with Systemd

Running with Systemd

The following guide will walk you through setting up a relayer as a system service. By the end of this document, you will have set up a Webb Relayer at a publicly accessible via an endpoint behind a reverse proxy, and fulfill the requirements for listing your relayer on app.webb.tools.

Getting Started

These instructions assume the user has access to a server on any Linux VM, and is logged into a user with sudo permissions.

Prerequisites

It is a requirement to have Nginx installed on the Linux machine, for instructions on how to install Nginx on the machine please visit the offical Nginx installation documentation here (opens in a new tab).

Basic Environment Setup

Following the instructions below, you will be able to run the relayer as a system service.

Update Ubuntu packages

apt update
# Update ubuntu packages
sudo apt update && sudo apt upgrade

Update Snap package

apt install
# Update snap packages
sudo apt install -y snapd
sudo snap install core; sudo snap refresh core

Install dependencies

apt install
# Install dependencies
sudo apt install gcc cmake pkg-config libssl-dev git clang libclang-dev
sudo apt install build-essential

Install Rust

rust
# Install rust
curl https://sh.rustup.rs -sSf | sh -s -- -y
export PATH=~/.cargo/bin:$PATH
source ~/.cargo/env

Install Certbot

certbot
# Install certbot
sudo snap install --classic certbot && sudo ln -s /snap/bin/certbot /usr/bin/certbot

Build Relayer from source

build
# Build from source
git clone https://github.com/webb-tools/relayer.git
cd relayer && cargo build --release --features cli

Creating a System Service

  1. Setup the relayer as a system service:

Let's first create a service file for the relayer:

Next, we will paste the following into the service file, and replace the <user> with the user that will be running the relayer:

  • This assumes the repo has been cloned in the home directory of the user
  • Paste the following into the service file, and replace the <user>:
sudo tee /etc/systemd/system/webb-relayer.service > /dev/null << EOF
[Unit]
Description=WebbRelayer

[Service]
User=<user>
Restart=always
RestartSec=3
Type=exec
Environment="/home/<user>/.config/webb-relayer/.env"
WorkingDirectory=/home/<user>/relayer
ExecStart=/home/<user>/relayer/target/release/webb-relayer -vvv -c /home/<user>/.config/webb-relayer/

[Install]
WantedBy=multi-user.target
EOF
  1. Enable and start the system service:
enable & start
sudo systemctl enable webb-relayer && sudo systemctl start webb-relayer

Nginx Setup

  1. Configure your registered domain name with your cloud service provider.

  2. Install nginx if it isn't already on your machine:

nginx
sudo apt install nginx

First, we will configure the endpoint linked to your domain name at port 80 for certificate generation

  1. Create nginx site files for your domain:
site files
cd /etc/nginx/sites-available &&
 
sudo cp default <domain name> &&
 
sudo ln -s /etc/nginx/sites-available/<domain name> /etc/nginx/sites-enabled/
  1. Modify the nginx sites-available file to:
default
server {
    listen 80;
    listen [::]:80;
 
    root /var/www/<domain name>/html;
    index index.html index.htm index.nginx-debian.html;
 
    server_name <domain name>;
 
    location / {
            try_files $uri $uri/ =404;
    }
}
  1. Check the nginx configuration
status nginx
sudo nginx -t
  1. If no issues exist, restart the nginx service:
restart nginx
sudo systemctl restart nginx

Next we will create the self-signed certificate and reconfigure for https and wss support

  1. Create the self-signed certificate:
certonly
sudo certbot certonly --nginx
  1. Modify the nginx site file:
site file
map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
}
 
server {
 
    # SSL configuration
    #
    listen 443 ssl;
    listen [::]:443 ssl;
 
    root /var/www/<domain name>/html;
 
    server_name <domain name>;
    ssl_certificate /etc/letsencrypt/live/<domain name>/cert.pem;
    ssl_certificate_key /etc/letsencrypt/live/<domain name>/privkey.pem;
    ssl_session_timeout 5m;
    ssl_protocols SSLv2 SSLv3 TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers   HIGH:!aNULL:!MD5;
    ssl_prefer_server_ciphers on;
 
    location / {
        proxy_pass http://127.0.0.1:9955;
        proxy_pass_request_headers on;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
    }
}
  1. Check Nginx configuration and restart the service:
restart nginx
sudo nginx -t && sudo systemctl restart nginx

Monitoring Setup

Relayers will want to setup monitoring to ensure maximum uptime and automatic restarts when things go awry.

  1. Install monit
install monit
sudo apt install -y monit
  1. modify the monitrc file at: /etc/monit/monitrc
monitrc
set httpd port 2812 and
use address localhost
allow localhost
 
set daemon 10
set log /var/log/monit.log
set idfile /var/lib/monit/id
set statefile /var/lib/monit/state
set eventqueue
    basedir /var/lib/monit/events
    slots 100
 
check process webb-relayer matching target/release/webb-relayer
    start program = "/bin/systemctl restart webb-relayer"
    stop program = "/bin/systemctl kill webb-relayer"
    if cpu > 90% for 20 cycles then exec "/bin/systemctl stop webb-relayer" and repeat every 10 cycles
    if cpu > 90% for 64 cycles then exec "/bin/systemctl kill webb-relayer" and repeat every 10 cycles
    if cpu > 90% for 64 cycles then alert
    if does not exist for 1 cycles then start
  1. restart monit and validate:
restart & validate
sudo monit reload && sudo monit validate

Dapp Integration

After completing the above steps, submit a PR with changes for your https endpoint in the Webb Dapp (opens in a new tab) repo.

Running with DockerConfiguration Options