Tutorials

Tutorial

Nginx Security Hardening on Ubuntu and Debian

Harden Nginx beyond its defaults with security headers, TLS 1.3, HSTS, method restrictions, and access controls. Each directive is tied to the specific attack it prevents.

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Tutorial

How to Set Up a Linux VPS Firewall with UFW and nftables

Configure a default-deny firewall on your Linux VPS using either UFW or nftables. Two paths, one goal: only the ports you choose stay open.

14 min readRead
Tutorial

WireGuard and Tailscale VPN on a Linux VPS

Set up WireGuard from scratch or deploy Tailscale for managed VPN access on Ubuntu 24.04 and Debian 12, with DNS leak prevention, PreSharedKey hardening, and a neutral comparison including Headscale.

17 min readRead
Tutorial

Secure n8n with Nginx Reverse Proxy, TLS, and Security Headers

Put your self-hosted n8n behind Nginx with Let's Encrypt TLS, security headers, rate limiting, firewall rules, and webhook protection. Every step includes a verification command.

13 min readRead
Tutorial

Docker Security Hardening: Rootless Mode, Seccomp, AppArmor on a VPS

Seven hardening layers for Docker on a VPS. Each section explains the threat, shows the fix with CLI and Compose syntax, and verifies it works.

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Tutorial

Self-Host Vaultwarden on a VPS with Docker Compose

Deploy a hardened Vaultwarden password manager on your VPS. Covers Docker Compose with read-only containers, fail2ban, SMTP for 2FA, backup and restore, and emergency access.

12 min readRead
Tutorial

Nginx Rate Limiting and DDoS Protection

Configure Nginx rate limiting with limit_req, limit_conn, and fail2ban to protect your server from brute-force attacks and application-layer DDoS without relying on third-party services.

10 min readRead
Tutorial

Install and Configure Fail2Ban on a Linux VPS

Set up Fail2Ban to block brute-force attacks on SSH and Nginx. Covers UFW and nftables ban actions, custom jails, recidive escalation, and filter testing on Ubuntu 24.04 and Debian 12.

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Tutorial

Secure Your AI Agent Server: Sandboxing, Firewalls, and Monitoring

AI agents execute arbitrary actions, consume unpredictable resources, and process untrusted input by design. This guide maps each threat to a concrete Linux control.

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Tutorial

Deploy OpenClaw Securely on a VPS

Install and lock down OpenClaw on a VPS with gateway authentication, TLS reverse proxy, Docker sandboxing, firewall hardening, and systemd isolation. Step-by-step with security hardening included.

14 min readRead
Tutorial

Set Up Let's Encrypt SSL/TLS for Nginx on Debian 12 and Ubuntu 24.04

Obtain and auto-renew free TLS certificates with Certbot for Nginx on Debian 12 or Ubuntu 24.04. Covers DNS setup, Certbot installation, HTTP-to-HTTPS redirect, TLS hardening, HTTP/2, HSTS, and the OCSP discontinuation.

11 min readRead
Tutorial

Fix Docker Bypassing UFW: 4 Tested Solutions for Your VPS

Docker manipulates iptables directly and ignores UFW rules. Your container ports are exposed to the internet even with ufw deny active. Here are four solutions with tradeoffs, each verified by scanning from an external host.

11 min readRead
Tutorial

SSH Hardening on a Linux VPS: Complete sshd_config Security Guide

Lock down SSH on your Debian 12 or Ubuntu 24.04 VPS. Ed25519 key generation, sshd_config hardening, ProxyJump bastion setup, cipher hardening, and ssh-audit verification. Tested on Debian 12 and Ubuntu 24.04.

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