🔗 AWS 119: Making the Connection - Attaching an IAM Policy to a User

🔑 Activating Permissions: Linking Policies to Identities

Hey Cloud Gatekeepers! 👋

Welcome to Day 19 of the #100DaysOfCloud Challenge: Attach IAM Policy to User! We are finishing the loop on our Identity and Access Management tasks with KodeKloud Engineer.

Over the last few days, we’ve built users and we’ve written custom policies. But right now, iamuser_jim has a "key" but no permissions to use it. Today, we are going to fix that by Attaching his specific policy to his account.

Our mission: Attach the existing policy iampolicy_jim to the user iamuser_jim.

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1. Introduction: The "Attachment" Principle 💡

In AWS, an IAM Policy is just a static document sitting in a library until it is associated with a "Principal" (a User, Group, or Role).

• In-line vs. Managed: While you can write policies directly inside a user (In-line), it is a best practice to use "Managed Policies" (like we are doing today) because they are reusable and easier to track.
• Immediate Effect: The moment you click "Attach," the permissions are live. There is no need for the user to log out and log back in.
• Why it Matters: This is how you delegate work. Jim might be our "S3 Admin" or "Database Auditor." By attaching the right policy, we give him the power to do his job without giving him the keys to the whole kingdom.

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2. Step-by-Step Guide: Attaching the Policy to Jim

We will use the IAM Dashboard to finalize this security link.

Step 2.1: Locate the User

1. Log in to the AWS Console.

1. Search for IAM and open the dashboard.

1. In the left sidebar, click on "Users".

1. Find and click on the name iamuser_jim.

Step 2.2: Add Permissions

1. Inside Jim's user summary page, look for the "Permissions" tab.

2. Click the "Add permissions" button on the right and select "Add permissions" from the dropdown.

Step 2.3: Attach Existing Policy Directly

1. Select the option "Attach policies directly".

1. In the Permissions policies search box, type iampolicy_jim.
2. Check the box next to the policy name when it appears.

Step 2.4: Review and Add

1. Click "Next" at the bottom.
2. Review the summary. You should see "Permissions boundary is not set" (which is normal for this task) and the policy name iampolicy_jim.
3. Click "Add permissions".

Success! iamuser_jim now has the specific powers defined in his custom policy. 🎉

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3. Key Takeaways 📝

• Granular Control: You can attach multiple policies to a single user if they have multiple responsibilities.
• Inheritance: Remember, if Jim were in a Group, he would also inherit all the policies attached to that group in addition to this direct policy.
• Global Visibility: You can see exactly which policies are affecting a user by looking at the "Permissions" tab at any time.

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4. Common Mistakes to Avoid 🚫

1. Direct Attachment Overload: In a large company, it's better to attach policies to Groups rather than individual users. Attaching directly to users (like we did today) is okay for specific exceptions, but can become a mess at scale.
2. Naming Confusion: Always ensure you are attaching iampolicy_jim to iamuser_jim. It’s easy to misclick when names are similar!
3. Policy Conflicts: If one policy says "Allow S3" and another says "Deny S3," Deny always wins in AWS.

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5. Conclusion + Call to Action! 🌟

Jim is now fully equipped to help the Nautilus team with their cloud migration! You've successfully managed the "Who" (User), the "What" (Policy), and the "How" (Attachment).

How are you finding the 100 Days of Cloud Challenge? 🛡️

• 💬 Let’s connect on LinkedIn: Have you ever accidentally "locked yourself out" by attaching a Deny policy? (We've all been there!) 👉 Hritik Raj
• ⭐ Support my journey on GitHub: Check out my full security and infrastructure logs. 👉 GitHub – 100 Days of Cloud