Infrastructure tutorials
Production-grade guides for Linux, servers, security and performance. Copy-paste commands, multi-distro support, written by engineers who run this in production.
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Linux
System administration, shell scripting, package management
Hosting & Servers
Web servers, reverse proxies, SSL, domains
Security
Firewalls, hardening, encryption, access control
Performance
Caching, optimization, profiling, load testing
Databases
MySQL, PostgreSQL, Redis, backups, replication
Networking
DNS, load balancing, VPN, TCP/IP, routing
DevOps
CI/CD, Docker, Kubernetes, automation
Monitoring
Logging, alerting, metrics, observability
Most viewed
Configure Linux system time synchronization with chrony and NTP hardening
linuxInstall and configure Caddy web server with automatic HTTPS and reverse proxy
hostingInstall and configure Uvicorn ASGI server with systemd and reverse proxy for FastAPI applications
hostingSet up Node.js application security with Helmet and rate limiting
securityInstall and configure PostgreSQL 17 with performance tuning and security hardening
databasesRecently published
Configure Jetty clustering and session replication for high availability
hostingConfigure Cherokee web server with MySQL database optimization and performance tuning
hostingConfigure Cassandra SSL encryption and authentication with security hardening
databasesInstall and configure ntopng for comprehensive network monitoring with traffic analysis and real-time dashboards
networkingOptimize Cassandra data modeling and query performance with advanced tuning and monitoring
databasesConfigure SSH key authentication and security hardening
Replace password authentication with SSH keys and implement comprehensive security hardening including fail2ban, audit logging, and access controls to protect your Linux servers from unauthorized access and brute force attacks.
Implement network security policies with iptables and firewalld for enterprise infrastructure protection
Configure enterprise-grade network security with iptables and firewalld, implementing zone-based policies, advanced rules, and comprehensive logging for production infrastructure protection.
Fix SSH sign_and_send_pubkey: signing failed: agent refused operation
Resolve SSH authentication errors when the SSH agent refuses to sign public keys. This tutorial covers checking agent status, fixing key permissions, restarting the agent, and troubleshooting SSH client configuration.
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