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
Install and configure Deno for web development with systemd and reverse proxy
hostingInstall 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
hostingInstall and configure Ollama for local AI models on Linux servers
devopsInstall and configure Uptime Kuma for website monitoring with SSL and email alerts
monitoringRecently published
Implement NGINX Plus active health checks for enterprise environments
hostingSetup Prometheus Blackbox Exporter for endpoint monitoring with SSL and alerting
monitoringConfigure Prometheus alerting with AlertManager notifications and webhook integration
monitoringConfigure Elasticsearch cross-cluster replication for disaster recovery
databasesConfigure InfluxDB 2.7 clustering for high availability with data replication and automated failover
databasesConfigure LDAP authentication for centralized user management with OpenLDAP and SSSD
Set up centralized user authentication using OpenLDAP server with SSSD client integration. Configure PAM and NSS for seamless login across multiple Linux systems with directory-based user management.
Configure SSH certificate authentication with CA signing for secure server access
Set up SSH certificate-based authentication using a Certificate Authority to eliminate individual key management. Create signed user certificates that provide secure, scalable access control for multiple servers and users.
Configure 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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