Run a GameSpy login emulator as a systemd service

gsserver.service

[Unit]
Description=GameSpy login emulation server
After=network-online.target

[Install]
WantedBy=multi-user.target

[Service]
Type=simple

WorkingDirectory=path_to_gsserver_folder
ExecStart=/usr/bin/wine path_to_gsserver.exe

Restart=always
RestartSec=1m
# Restart every hour to avoid long hangs on "Press any key to exit..."
RuntimeMaxSec=1h
# gsserver.exe will never exit normally, so send SIGTERM after a few seconds
TimeoutStopSec=5s

# Since the GameSpy emulator launched in interactive terminal, we need to attach something to stdin or it will go crazy
Sockets=gsserver.socket
StandardInput=socket
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=%n

User=some_non_privileged_user

gsserver.socket

[Socket]
ListenFIFO=%t/gsserver.stdin
Service=gsserver.service

setup-gsserver.sh

#!/usr/bin/env bash

GSSERVER_DIR=/opt/gsserver
GSSERVER_BIN=gsserver.exe
USER=gsserver

# Ensure service dir exists and contains binary
if [ ! -d "$GSSERVER_DIR" ]; then
    echo "$GSSERVER_DIR does not exists, please create it manually"
    exit 1
fi

if [ ! -f "$GSSERVER_DIR/$GSSERVER_BIN" ]; then
    echo "$GSSERVER_DIR/$GSSERVER_BIN does not exists, please add it"
    exit 1	
fi

# Install wine
apt update
apt install curl ca-certificates
dpkg --add-architecture i386
apt update
apt install wine32

# Add service user
adduser --disabled-login --gecos "" "$USER"

# Install mono
runuser - "$USER" -c "curl -O https://dl.winehq.org/wine/wine-mono/7.0.0/wine-mono-7.0.0-x86.msi && wine msiexec /i wine-mono-7.0.0-x86.msi /quiet > /dev/null 2>&1"

# Transfer ownership of folder to service user and set up permissions
chown -R "$USER":"$USER" "$GSSERVER_DIR"
chmod -R 644 "$GSSERVER_DIR"
chmod 755 "$GSSERVER_DIR"
chmod 755 "$GSSERVER_DIR/$GSSERVER_BIN"

# Set up systemd service
tee /etc/systemd/system/gsserver.service > /dev/null << EOF 
[Unit]
Description=GameSpy login emulation server
After=network-online.target

[Install]
WantedBy=multi-user.target

[Service]
Type=simple

WorkingDirectory=$GSSERVER_DIR
ExecStart=/usr/bin/wine $GSSERVER_DIR/$GSSERVER_BIN

Restart=always
RestartSec=1m
# Restart every hour to avoid long hangs on "Press any key to exit..."
RuntimeMaxSec=1h
# gsserver.exe will never exit normally, so send SIGTERM after a few seconds
TimeoutStopSec=5s

# Since the GameSpy emulator launched in interactive terminal, we need to attach something to stdin or it will go crazy
Sockets=gsserver.socket
StandardInput=socket
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=%n

User=$USER
EOF

# Set up socket for STDIN
tee /etc/systemd/system/gsserver.socket > /dev/null << EOF 
[Socket]
ListenFIFO=%t/gsserver.stdin
Service=gsserver.service
EOF

# Set up ownership and permissions for service files
chown root:root /etc/systemd/system/gsserver.service /etc/systemd/system/gsserver.socket
chmod 644 /etc/systemd/system/gsserver.service /etc/systemd/system/gsserver.socket

# Reload service files
systemctl daemon-reload

# Enable and start service
echo "

You can now enable the GameSpy login emulation service using: systemctl enable gsserver
And then start the service: systemctl start gsserver
Ideally, set up the following cron job for the $USER user:
*/5 * * * * /usr/bin/echo \"connections\" > /run/gsserver.stdin"