Step-by-step Linux, Kubernetes and cloud tutorials drawn from over 10 years of keeping production environments running. Every command tested, nothing hand-waved.
Monitor remote Linux servers with Nagios and NRPE: install NRPE on Ubuntu and RHEL, build check_nrpe, fix allowed_hosts errors, and verify real alerts.
Continue Reading →Install Nagios Core 4.5.14 from source on Ubuntu 26.04 and RHEL 9: plugins, web UI login, adding a remote host, and a verified working setup with real output.
Continue Reading →Install Zabbix agent 2 on Ubuntu and RHEL 9, connect it to Zabbix server, add hosts manually or by autoregistration, and encrypt with PSK. Real output.
Continue Reading →Install Zabbix 7.4 on Ubuntu 26.04 with MySQL 8.4, Apache and PHP-FPM. Real output, the proxy_fcgi fix Apache needs, the setup wizard and a verified working setup.
Continue Reading →Set up a self-hosted GitHub Actions runner on Ubuntu and AlmaLinux, register it, run a real job, and watch it survive a reboot. Includes a real AlmaLinux 10 bug.
Continue Reading →Set up nginx as a load balancer with real config and real output: round robin, weighted round robin, least_conn, ip_hash sticky sessions, passive health checks, SSL termination, WebSocket proxying and per-backend logging.
Continue Reading →The full progression from Let’s Encrypt and Certbot on Nginx with automatic renewal, to cert-manager and Kubernetes Ingress. Real terminal output, including the two failures beginners actually hit.
Continue Reading →How to read ping, traceroute and mtr output on Linux: packet loss, jitter, path MTU with ping -M do, why traceroute asterisks are often a false alarm, and a real troubleshooting workflow on Ubuntu 24.04 and RHEL 9.
Continue Reading →How to search Linux logs fast with grep, zgrep, journalctl and ripgrep: rotated .gz files, time windows, top-IP reports and the traps, on Ubuntu 24.04 and RHEL 9.
Continue Reading →A bottom-up method for Linux network troubleshooting: link and ARP, routing, then a live demo of refused versus firewall-filtered connections, then DNS. Real output on Ubuntu 24.04 and RHEL 9.
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