IAM users and groups in AWS - Step-by-Step Execution

Process Flow - IAM users and groups

Create IAM User

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Create IAM Group

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Attach Policies to Group

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Add User to Group

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User inherits Group Permissions

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User can access AWS resources based on permissions

This flow shows how you create users and groups, attach permissions to groups, add users to groups, and how users get permissions from groups.

Execution Sample

AWS

1. Create user 'Alice'
2. Create group 'Developers'
3. Attach 'AmazonS3ReadOnlyAccess' policy to 'Developers'
4. Add 'Alice' to 'Developers'

This example creates a user and a group, gives the group read-only access to S3, then adds the user to the group so she inherits that access.

Process Table

Step	Action	Resource Created/Modified	Permissions Assigned	Result
1	Create IAM user 'Alice'	User: Alice	No permissions yet	User 'Alice' exists with no permissions
2	Create IAM group 'Developers'	Group: Developers	No permissions yet	Group 'Developers' exists with no permissions
3	Attach 'AmazonS3ReadOnlyAccess' policy to 'Developers'	Group: Developers	S3 Read-Only Access	Group 'Developers' has S3 read-only permissions
4	Add user 'Alice' to group 'Developers'	User: Alice	Inherits S3 Read-Only Access from group	User 'Alice' can read S3 buckets
5	User 'Alice' tries to write to S3	User: Alice	S3 Read-Only Access	Access denied - write not allowed
6	User 'Alice' tries to read from S3	User: Alice	S3 Read-Only Access	Access granted - read allowed

💡 User 'Alice' inherits permissions from group 'Developers'; actions allowed or denied based on those permissions.

Status Tracker

Entity	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
User 'Alice' Permissions	None	None	None	None	S3 Read-Only Access (via group)	S3 Read-Only Access (via group)
Group 'Developers' Permissions	None	None	None	S3 Read-Only Access	S3 Read-Only Access	S3 Read-Only Access

Key Moments - 3 Insights

Why does user 'Alice' have permissions after being added to the group?

Because groups hold permissions, and when a user is added to a group, the user inherits all permissions assigned to that group, as shown in step 4 of the execution_table.

Can user 'Alice' write to S3 after inheriting read-only access?

No, the permissions are read-only, so write attempts are denied, as shown in step 5 of the execution_table.

What happens if a user is not added to any group?

The user has no permissions unless permissions are assigned directly to the user. In this example, before step 4, 'Alice' has no permissions.

Visual Quiz - 3 Questions

Look at the execution_table, what permissions does user 'Alice' have immediately after step 3?

A S3 Read-Only Access

B No permissions

C Full S3 Access

D Write access to S3

💡 Hint

Check the 'Permissions Assigned' column for user 'Alice' at step 3 in the execution_table.

At which step does user 'Alice' gain S3 read-only permissions?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Look for when 'Alice' is added to the group that has the permissions in the execution_table.

If the 'AmazonS3ReadOnlyAccess' policy was attached directly to user 'Alice' instead of the group, how would the execution_table change?

A Step 3 would show policy attached to user, and step 4 would be adding user to group with no permissions

B Step 4 would be skipped

C User 'Alice' would have permissions after step 1

D No change in execution_table

💡 Hint

Consider where the policy is attached and how that affects the steps in the execution_table.

Concept Snapshot

IAM Users and Groups:
- Users represent individual people or services.
- Groups hold permissions (policies).
- Attach policies to groups, not users directly.
- Add users to groups to grant permissions.
- Users inherit all group permissions.
- Permissions control access to AWS resources.

Full Transcript

This visual execution shows how IAM users and groups work in AWS. First, you create a user named 'Alice' with no permissions. Then, you create a group called 'Developers' which also starts with no permissions. Next, you attach a policy called 'AmazonS3ReadOnlyAccess' to the group, giving it permission to read S3 buckets. After that, you add 'Alice' to the 'Developers' group. Because of this, 'Alice' inherits the group's permissions and can read from S3. Attempts to write to S3 are denied because the permission is read-only. This demonstrates how users gain permissions through group membership, simplifying permission management.