access control Archives - ITFROMZERO

Managing Access Control Lists (ACL) on CentOS Stream 9: Fine-Grained File Permissions Beyond chmod/chown for Multi-User Enterprise Environments

By IT From Zero November 14, 2026

Traditional chmod/chown permissions only cover three entities (owner/group/others), which isn't flexible enough for multi-user environments. This guide walks through using setfacl and getfacl on CentOS Stream 9 to set granular file and directory permissions per user and group, with practical examples and instructions for backing up ACLs during server migration.

Development

Implementing ABAC with Open Policy Agent (OPA) and Node.js for Complex Microservices Systems

By IT From Zero July 17, 2026

When RBAC is no longer sufficient for complex authorization logic in Microservices, Open Policy Agent (OPA) and the ABAC model offer a practical solution. This post shares production experience with Node.js, Rego policies, and how to integrate OPA into Express middleware.

Linux

How to Configure sudo and the sudoers File on Linux: Safe Permission Management for Each User

By IT From Zero March 15, 2026

A comparison of 3 approaches to granting sudo access on Linux: adding users to the wheel/sudo group, editing /etc/sudoers directly, or using /etc/sudoers.d/. Covers the pros and cons of each approach along with practical configuration guides using visudo, Command Aliases, and NOPASSWD for team-based production environments.

MySQL

MySQL User Management and Access Control: Tips & Tricks from Real-World Experience

By IT From Zero March 3, 2026

A practical guide to MySQL user management and access control following the Principle of Least Privilege — creating users, managing GRANT/REVOKE permissions, and setting up a solid foundation for production projects. Real-world tips and tricks to protect your database from unnecessary risk.