1. Put this file in /etc/systemd/system/secret-lcd.service
  2. Make sure /usr/local/bin/secretcli is the right path for secretcli
  3. Make sure ports 80 and 443 are open
  4. Make sure --chain-id is the right chain ID
  5. Make sure ubuntu is the right user
[Unit]
Description=Secret LCD server
After=network.target

[Service]
Type=simple
ExecStart=/usr/local/bin/secretcli rest-server --trust-node=true --chain-id secret-2 --laddr tcp://127.0.0.1:1337
User=ubuntu
Restart=always
StartLimitInterval=0
RestartSec=3
LimitNOFILE=65535

[Install]
WantedBy=multi-user.target

Enable on startup and start:

sudo systemctl enable secret-lcd
sudo systemctl start  secret-lcd

Then, install caddy: https://caddyserver.com/docs/download#debian-ubuntu-raspbian
Edit /etc/caddy/Caddyfile to have this as the whole content (Replace bootstrap.int.testnet.enigma.co with your domain name):

bootstrap.int.testnet.enigma.co

header {
        Access-Control-Allow-Origin  *
        Access-Control-Allow-Methods *
        Access-Control-Allow-Headers *
}

@corspreflight {
	method OPTIONS
	path   *
}

respond @corspreflight 204

reverse_proxy 127.0.0.1:1337

And then:

sudo systemctl enable  caddy.service
sudo systemctl restart caddy.service

# Scripted

First Set DOMAIN_NAME="$DOMAIN_NAME_OF_THIS_MACHINE".

echo "
Description=Secret LCD server
After=network.target

[Service]
Type=simple
ExecStart=$(which secretcli) rest-server --trust-node=true --chain-id secret-2 --laddr tcp://127.0.0.1:1337
User=$USER
Restart=always
StartLimitInterval=0
RestartSec=3
LimitNOFILE=65535

[Install]
WantedBy=multi-user.target
" | sudo tee /etc/systemd/system/secret-lcd.service

sudo systemctl enable secret-lcd
sudo systemctl start  secret-lcd

echo "deb [trusted=yes] https://apt.fury.io/caddy/ /" |
        sudo tee -a /etc/apt/sources.list.d/caddy-fury.list
sudo apt-get update
sudo apt-get install -y caddy

echo "
$DOMAIN_NAME

header {
        Access-Control-Allow-Origin  *
        Access-Control-Allow-Methods *
        Access-Control-Allow-Headers *
}

@corspreflight {
	method OPTIONS
	path   *
}

respond @corspreflight 204

reverse_proxy 127.0.0.1:1337
" | sudo tee /etc/caddy/Caddyfile

sudo systemctl enable  caddy.service
sudo systemctl restart caddy.service