what is sentry-hardening fr?

Sentry is a security hardening and real-time monitoring suite for Debian-based Linux systems, packaged as a shell script. It does two jobs: locking down your system's attack surface, and then continuously watching for changes or suspicious activity. The hardening phase disables services and protocols that attackers commonly probe. Bluetooth is fully blacklisted at the kernel level. Network discovery services such as mDNS, Avahi, Samba broadcasting, and printer discovery are shut down. USB auto-mount is disabled to protect against BadUSB attacks, which are malicious USB devices that pretend to be keyboards. WiFi is configured for MAC address randomization and power-save stealth mode. A firewall using UFW and iptables blocks discovery protocols, and kernel security parameters are applied including SYN cookies and source routing disabled. The watchdog runs as a persistent background service and alerts you if anything changes: processes running from temporary directories, hardened services trying to restart, new ports appearing on the network, blacklisted kernel modules being loaded, firewall rules being altered, critical system binaries being modified, new outbound network connections, or new USB devices being inserted. Alerts appear as colored terminal output, broadcast messages to all logged-in users, desktop popups if a graphical interface is available, and entries in a dedicated log file. Hardening rules are reapplied every 15 minutes via a cron job and restored on every boot via systemd services. Tested on Debian 12, Ubuntu 24.04 LTS, Kali Linux, Parrot Security, and Linux Mint 22. The tech stack is Shell scripting, systemd, UFW, and iptables. The license is MIT.