IAM users and groups in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an IAM user in AWS?

An IAM user is an identity that represents a person or service who interacts with AWS. It has credentials to access AWS resources securely.

beginner

What is the purpose of an IAM group?

An IAM group is a collection of IAM users. It helps manage permissions by assigning policies to the group instead of individual users.

intermediate

How do IAM groups simplify permission management?

By assigning permissions to a group, all users in that group inherit those permissions. This avoids setting permissions one by one for each user.

intermediate

Can IAM users belong to multiple groups?

Yes, an IAM user can be a member of multiple groups, inheriting permissions from all those groups combined.

advanced

What is the difference between IAM user permissions and group permissions?

User permissions are policies attached directly to a user. Group permissions come from policies attached to groups the user belongs to. Both combine to define effective permissions.

What does an IAM group in AWS primarily help with?

A Managing multiple users' permissions together

B Creating new AWS accounts

C Storing data securely

D Running applications

IAM groups help manage permissions for multiple users by grouping them and assigning policies to the group.

Can an IAM user exist without belonging to any group?

A Yes, users can exist alone with direct permissions

B Only if the user is an admin

C No, every user must be in a group

D Only if the user is temporary

IAM users can have permissions assigned directly without being in any group.

If a user belongs to two groups with different permissions, what happens?

A User loses all permissions

B User gets permissions from only one group

C User gets combined permissions from both groups

D User must choose which group to use

Permissions from all groups a user belongs to are combined to form the user's effective permissions.

What is NOT a feature of IAM users?

A They have credentials to access AWS

B They can belong to groups

C They can be assigned permissions directly

D They automatically have admin rights

IAM users do not automatically have admin rights; permissions must be explicitly assigned.

Why is it better to assign permissions to groups rather than individual users?

A Groups are faster to create

B Groups reduce repetitive permission assignments

C Users cannot have permissions directly

D Groups automatically secure data

Assigning permissions to groups reduces the need to assign permissions repeatedly to each user.

Explain how IAM users and groups work together to manage access in AWS.

Think about how a team shares access rights through group membership.

Describe the benefits of using IAM groups instead of assigning permissions directly to each user.

Imagine managing keys for a building by giving them to groups instead of individuals.

Practice

1. What is the main purpose of an IAM group in AWS?

easy

A. To organize multiple IAM users and assign permissions collectively

B. To store data securely in the cloud

C. To create virtual servers for applications

D. To monitor network traffic in AWS

Solution

1. Step 1: Understand IAM user and group roles

   IAM users represent individuals or services, while groups organize these users.

2. Step 2: Identify the purpose of groups

   Groups allow assigning permissions to many users at once, simplifying management.

3. Final Answer:

   To organize multiple IAM users and assign permissions collectively -> Option A

4. Quick Check:

   IAM groups = organize users + assign permissions [OK]

Hint: Groups bundle users for easy permission management [OK]

Common Mistakes:

• Confusing groups with storage or servers
• Thinking groups monitor network traffic
• Believing groups are individual user accounts

2. Which of the following is the correct way to add an IAM user named alice to a group named Developers using AWS CLI?

easy

A. aws iam add-group-to-user --group-name Developers --user-name alice

B. aws iam attach-user-policy --user-name alice --policy-name Developers

C. aws iam add-user-to-group --user-name alice --group-name Developers

D. aws iam create-group --group-name Developers --user alice

Solution

1. Step 1: Recall AWS CLI command for adding user to group

   The correct command is aws iam add-user-to-group with parameters --user-name and --group-name.

2. Step 2: Match command syntax with options

   aws iam add-user-to-group --user-name alice --group-name Developers matches the correct syntax exactly.

3. Final Answer:

   aws iam add-user-to-group --user-name alice --group-name Developers -> Option C

4. Quick Check:

   Correct CLI command = aws iam add-user-to-group --user-name alice --group-name Developers [OK]

Hint: Use 'add-user-to-group' command with user and group names [OK]

Common Mistakes:

• Using 'attach-user-policy' instead of adding to group
• Confusing 'create-group' with adding users
• Reversing user and group parameters

3. Given the following IAM group policy attached to group Admins:

{
  "Version": "2012-10-17",
  "Statement": [{
    "Effect": "Allow",
    "Action": "s3:*",
    "Resource": "*"
  }]
}

If user bob is added to the Admins group, what permissions does bob have on S3?

medium

A. Full access to all S3 actions and resources

B. Read-only access to S3 buckets

C. No access to S3 unless user policy allows it

D. Access only to S3 buckets created by bob

Solution

1. Step 1: Analyze the group policy permissions

   The policy allows all S3 actions (s3:*) on all resources (*), meaning full access.

2. Step 2: Understand group membership effect

   User bob inherits all permissions from the Admins group.

3. Final Answer:

   Full access to all S3 actions and resources -> Option A

4. Quick Check:

   Group policy allows s3:* on * = full access [OK]

Hint: s3:* on * means full S3 access [OK]

Common Mistakes:

• Assuming user needs separate policy for access
• Thinking group policies restrict to created buckets
• Confusing read-only with full access

4. You tried to add user carol to group Managers using this command:

aws iam add-user-to-group --group-name Managers --user carol

But it failed. What is the error in this command?

medium

A. The command should be 'aws iam add-group-to-user' instead

B. The parameter should be --user-name, not --user

C. The group name should be specified after --user-name

D. The user name must be in quotes

Solution

1. Step 1: Check AWS CLI command syntax

   The correct parameter for specifying the user is --user-name, not --user.

2. Step 2: Identify the error in the command

   Using --user causes the command to fail because it is invalid.

3. Final Answer:

   The parameter should be --user-name, not --user -> Option B

4. Quick Check:

   Correct parameter = --user-name [OK]

Hint: Use --user-name, not --user, for specifying IAM user [OK]

Common Mistakes:

• Using incorrect parameter names
• Swapping user and group parameters
• Adding unnecessary quotes around names

5. You want to create a secure setup where users in the Developers group can only start and stop EC2 instances, but not terminate them. Which IAM policy snippet attached to the group achieves this?

hard

A. {
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": ["ec2:StartInstances", "ec2:StopInstances", "ec2:TerminateInstances"],
"Resource": "*"
}]
}

B. {
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "ec2:*",
"Resource": "*"
}]
}

C. {
"Version": "2012-10-17",
"Statement": [{
"Effect": "Deny",
"Action": "ec2:TerminateInstances",
"Resource": "*"
}]
}

D. {
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": ["ec2:StartInstances", "ec2:StopInstances"],
"Resource": "*"
}]
}

Solution

1. Step 1: Understand required permissions

   Users should only start and stop instances, so allow only those actions.

2. Step 2: Evaluate policy options

   { "Version": "2012-10-17", "Statement": [{ "Effect": "Allow", "Action": ["ec2:StartInstances", "ec2:StopInstances"], "Resource": "*" }] } allows only StartInstances and StopInstances. { "Version": "2012-10-17", "Statement": [{ "Effect": "Allow", "Action": "ec2:*", "Resource": "*" }] } allows all EC2 actions, including terminate. { "Version": "2012-10-17", "Statement": [{ "Effect": "Deny", "Action": "ec2:TerminateInstances", "Resource": "*" }] } denies terminate but does not allow start/stop explicitly. { "Version": "2012-10-17", "Statement": [{ "Effect": "Allow", "Action": ["ec2:StartInstances", "ec2:StopInstances", "ec2:TerminateInstances"], "Resource": "*" }] } allows terminate, which is not desired.

3. Final Answer:

   Policy allowing only start and stop EC2 instances -> Option D

4. Quick Check:

   Allow only start/stop, no terminate = { "Version": "2012-10-17", "Statement": [{ "Effect": "Allow", "Action": ["ec2:StartInstances", "ec2:StopInstances"], "Resource": "*" }] } [OK]

Hint: Allow only needed actions, avoid wildcard ec2:* [OK]

Common Mistakes:

• Using ec2:* allows unwanted terminate action
• Only denying terminate without allowing start/stop
• Including terminate in allowed actions