Linux for DevOps

The core Linux concepts every DevOps engineer touches daily: where the system keeps its files, how users and permissions gate access, and how processes are started, inspected, and stopped.

The command-line toolkit for finding, filtering, and transforming text — grep, sed, awk, find, and the piping and redirection that chain them into real workflows like log filtering.

Installing and updating software with the system package manager, and running it reliably as a service with systemd, including writing unit files and reading logs through journald.

The networking commands used to diagnose connectivity, inspect open ports, resolve DNS, and reason about basic firewall rules.

Measuring disk usage, memory, and CPU load, and using them together to systematically diagnose a slow or resource-exhausted server.

Key-based SSH authentication, transferring files securely, managing many hosts through the SSH config file, and locking down a server against common SSH attacks.