#Security
15 posts
RHEL Intermediate #1: Intro to SELinux — Enforcing/Permissive, Labels, Troubleshooting
A beginner-friendly introduction to SELinux, RHEL's last security layer. Covers the three modes Enforcing/Permissive/Disabled, the shape of labels (context) attached to every file and process, viewing them with ls -Z / ps -Z, fixing labels with chcon/restorecon, making permanent changes via semanage fcontext, toggling booleans, and troubleshooting AVC denials with audit2allow and sealert.
RHEL Basics #7: Basic Security — firewalld, SSH Hardening
RHEL's firewall abstraction firewalld and its zone model, the firewall-cmd command set (permanent vs runtime), the four standard SSH hardening steps — disable password auth, key-based auth, lock down root login, change the port, split sshd_config.d. The final post of the series.
AWS Basics #2: IAM — Users, Groups, Roles, Policies
The four elements of IAM — Users, Groups, Roles, Policies. JSON policy syntax, the essence of AssumeRole, and permission design patterns that hold up in production.