--- name: user-management description: Manage users, groups, and permissions on Linux systems. Configure sudo and access controls. Use when managing system access. license: MIT metadata: author: devops-skills version: "1.0" --- # User Management Manage users, groups, and permissions. ## User Operations ```bash # Create user useradd -m -s /bin/bash username passwd username # Delete user userdel -r username # Modify user usermod -aG sudo username usermod -s /bin/zsh username ``` ## Group Management ```bash # Create group groupadd developers # Add user to group usermod -aG developers username gpasswd -a username developers # Remove from group gpasswd -d username developers ``` ## Sudo Configuration ```bash # /etc/sudoers.d/developers %developers ALL=(ALL) NOPASSWD: /usr/bin/docker username ALL=(ALL) NOPASSWD: ALL ``` ## File Permissions ```bash chmod 755 file # rwxr-xr-x chmod u+x file # Add execute for user chown user:group file # Change ownership chown -R user:group dir/ # ACLs setfacl -m u:user:rx file getfacl file ``` ## Best Practices - Use groups for access control - Minimal sudo privileges - Regular access reviews - Strong password policies