#Red Hat
42 posts
Red Hat Certified Engineer (RHCE) #7: Jinja2 Templates — Filters, Control Flow, and lookup
The seventh post in the Red Hat Certified Engineer (RHCE) series. We render .j2 files into per-host configuration with the template module, cover Jinja2 syntax for variable output, for, and if, plus filters like default, upper, join, and to_nice_yaml, read files and environment variables with lookup, and even handle whitespace control — all in the form the exam asks for.
Red Hat Certified System Administrator (RHCSA) #4: Boot and the system — systemd, target, GRUB2, password recovery
The fourth post in the Red Hat Certified System Administrator (RHCSA) series. We work through the structure of systemd and how to control services with systemctl, switching the boot target, editing kernel parameters in GRUB2, and the single most frequent RHCSA task — root password recovery with rd.break — by typing the commands ourselves.
Red Hat Certified Engineer (RHCE) #6: Variables and facts — precedence, magic vars, custom facts
The sixth post in the Red Hat Certified Engineer (RHCE) series. From a hands-on angle, we cover where variables are defined (play vars, vars_files, group_vars/host_vars, extra-vars, register) and their reference syntax, the precedence rules where extra-vars always wins, the facts gathered by gather_facts and how to reach them through ansible_facts, how register stores a task result, magic variables like hostvars and groups, and finally custom facts you build under /etc/ansible/facts.d.
Red Hat Certified System Administrator (RHCSA) #3 Shell scripting: conditionals, loops, arguments, exit codes
The third post in the Red Hat Certified System Administrator (RHCSA) series. To write the simple bash scripts that show up regularly on the RHCSA exam, we type our way through shebang and variable quoting, positional arguments and exit codes, test/if/case conditionals and for/while/until loops, command substitution and arithmetic, read input and functions. At the end we write a real-world script that validates arguments and processes multiple targets in a loop.
Red Hat Certified Engineer (RHCE) #5: Playbook Basics — task, handler, idempotency
The fifth post in the Red Hat Certified Engineer (RHCE) series. We work through the YAML structure of a playbook and the play/task relationship, writing module tasks and the recommendation to name them, the handler-and-notify pattern that runs once at the end only when something changed, the idempotency that surfaces through changed and ok, the idempotency stopgaps for command/shell (creates/removes), and ansible-playbook versus ansible-navigator run plus --check/--diff/--syntax-check — all from a hands-on exam point of view.
Red Hat Certified System Administrator (RHCSA) #2 Essential Tools: bash, vi, redirection, find/grep, archive, ssh
The second post in the Red Hat Certified System Administrator (RHCSA) series. We cover the shell fundamentals that everything else is built on — input/output redirection and pipes, finding and processing matching files with find and grep, text processing with less,sort,sed,awk, the modes and search-and-replace of the vi editor, tar,gzip archiving, remote work with ssh and scp, and how to wield man pages as a weapon in an exam room with no internet — all with command examples.
Red Hat Certified Engineer (RHCE) #4 Ad-hoc commands: running modules on the spot
The fourth post in the Red Hat Certified Engineer (RHCE) series. We lay out the ad-hoc structure for running modules on the spot with the ansible command, the frequently used modules such as ping, command, shell, copy, file, dnf, service, user, and lineinfile, host patterns, become, and how to look up options with ansible-doc — all worked through with examples.
Red Hat Certified System Administrator (RHCSA) #1: The Exam — EX200 format, environment, study strategy
The opening post of the Red Hat Certified System Administrator (RHCSA) series. We lay out the format and domains of the EX200 hands-on exam, the 210/300 passing line, the testing environment where you work with man pages only and no internet, and the study strategy that turns the feel you built on the [RHEL operations track](/en/posts/rhel-basics-1) into hands-on exam results. This 16-part series targets an RHCSA pass, wrapping up with a full-scale mock exam in #16.
Red Hat Certified Engineer (RHCE) #3: Config Files and Connectivity — ansible.cfg, ssh, become
The third post in the Red Hat Certified Engineer (RHCE) series. We lay out the lookup precedence and key settings of ansible.cfg, which governs how Ansible behaves, the procedure for setting up SSH key-based connections with ssh-copy-id, and how to escalate privileges with become. We build a per-project ansible.cfg and become configuration by hand — a perennial exam favorite — and check the connection.
Red Hat Certified Engineer (RHCE) #2 Inventory: static, dynamic, group/host_vars
The second post in the Red Hat Certified Engineer (RHCE) series. We work through the inventory that defines what Ansible operates on — static inventory in both INI and YAML form, groups and groups of groups (children), range notation, and the directory layout that splits variables into group_vars and host_vars. We also cover how to verify with ansible-inventory, the concept of dynamic inventory, and the task patterns that show up again and again on the exam.
Red Hat Certified Engineer (RHCE) #1: Exam Overview — the environment, time management, ansible-navigator vs ansible-playbook
The opening post of the Red Hat Certified Engineer (RHCE) series. Assuming you already hold RHCSA, we lay out the format and domains of the EX294 hands-on exam, the 210/300 passing score and 4-hour testing environment, the nature of the exam as Ansible automation, and the ansible-navigator vs ansible-playbook execution styles. This 19-part series targets an RHCE pass, wrapping up with a full-scale mock exam in #19.
RHEL in Practice #6 Wrapping Up the Track: A Reference Architecture
The final post of the RHEL in Practice track. We tie together the nginx web server, PostgreSQL, Podman containers, Cockpit/PCP monitoring, and Ansible automation covered across posts #1 through #5 into a single reference architecture, drawing the full picture of running one small web service on a single box. We also walk through an operations checklist covering persistence, SELinux, firewalld, backups, logging, permissions, and time sync, plus the learning path that leads on to the RHCSA and RHCE certifications.