SRJahirTech

AWS + Linux Combo — Part 10
IAM & Linux Permissions

This part explains one of the most misunderstood areas in cloud engineering: permissions. Most breaches happen because of bad permission design.

AWS IAM vs Linux Users

• AWS IAM controls cloud access
• Linux users control server access
• Both must follow least privilege

Linux Permission Model

Every file has:

• Owner
• Group
• Others

ls -l

chmod Explained Simply

chmod 640 config.env

• Owner: read + write
• Group: read
• Others: no access

chown for Ownership

chown appuser:www-data app/

Ownership mistakes cause most deployment failures.

Least Privilege Principle

Give only what is needed — nothing more. This applies to:

• IAM roles
• Linux users
• Services

Common Beginner Mistakes

• chmod 777 everywhere
• Running everything as root
• Sharing AWS root account

Professional Mindset

If permissions are boring to you, you are not ready for production systems yet.