IAM policies (JSON structure) in AWS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the version of the IAM policy.

AWS

{
  "Version": "[1]",
  "Statement": []
}

Drag options to blanks, or click blank then click option'

A2020-01-01

B2012-10-17

C2015-05-20

D2010-09-09

Attempts:

3 left

💡 Hint

Common Mistakes

Using an incorrect or unsupported version date.

Leaving the version field empty.

The correct version for IAM policies is 2012-10-17. This version supports all current features.

2fill in blank

medium

Complete the code to specify the effect of the IAM policy statement.

AWS

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "[1]",
      "Action": "s3:ListBucket",
      "Resource": "*"
    }
  ]
}

Drag options to blanks, or click blank then click option'

ABlock

BDeny

CPermit

DAllow

Attempts:

3 left

💡 Hint

Common Mistakes

Using words like 'Permit' or 'Block' which are not valid in IAM policies.

Leaving the Effect field blank.

The Effect field must be either Allow or Deny. Here, Allow grants permission.

3fill in blank

hard

Fix the error in the action name to correctly specify S3 bucket listing.

AWS

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "[1]",
      "Resource": "*"
    }
  ]
}

Drag options to blanks, or click blank then click option'

As3:ListAllBuckets

Bs3:ListBuckets

Cs3:ListBucket

Ds3:ListBucketObjects

Attempts:

3 left

💡 Hint

Common Mistakes

Using plural forms like 'ListBuckets' which do not exist.

Adding extra words to the action name.

The correct action to list objects in a bucket is s3:ListBucket. Other options are invalid.

4fill in blank

hard

Fill both blanks to specify a policy statement that denies deleting objects from a specific bucket.

AWS

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "[1]",
      "Action": "[2]",
      "Resource": "arn:aws:s3:::example-bucket/*"
    }
  ]
}

Drag options to blanks, or click blank then click option'

ADeny

BAllow

Cs3:DeleteObject

Ds3:PutObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Allow' instead of 'Deny' for blocking actions.

Choosing the wrong action like 's3:PutObject'.

To deny deleting objects, the Effect must be Deny and the Action must be s3:DeleteObject.

5fill in blank

hard

Fill all three blanks to create a policy statement that allows reading objects from a bucket only if the request comes from a specific IP address.

AWS

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "[1]",
      "Action": "[2]",
      "Resource": "arn:aws:s3:::my-bucket/*",
      "Condition": {
        "IpAddress": {
          "aws:SourceIp": "[3]"
        }
      }
    }
  ]
}

Drag options to blanks, or click blank then click option'

AAllow

Bs3:GetObject

C203.0.113.0/24

DDeny

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Deny' instead of 'Allow' for granting access.

Choosing the wrong action like 's3:PutObject'.

Incorrect IP address format.

The policy allows (Allow) the action s3:GetObject only if the request comes from the IP range 203.0.113.0/24.

Practice

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

easy

A. To create virtual machines

B. To define permissions for users and resources

C. To monitor network traffic

D. To store data in the cloud

Solution

1. Step 1: Understand IAM policy role

   An IAM policy is a JSON document that specifies permissions for AWS users, groups, or roles.

2. Step 2: Identify main function

   Its main function is to control what actions are allowed or denied on AWS resources.

3. Final Answer:

   To define permissions for users and resources -> Option B

4. Quick Check:

   IAM policy = permissions definition [OK]

Hint: IAM policies control access permissions in AWS [OK]

Common Mistakes:

• Confusing IAM policies with data storage
• Thinking IAM policies monitor network traffic
• Assuming IAM policies create virtual machines

2. Which of the following is the correct JSON key to specify the effect of a statement in an IAM policy?

easy

A. "Permission"

B. "Action"

C. "Resource"

D. "Effect"

Solution

1. Step 1: Recall IAM policy statement keys

   IAM policy statements include keys like Effect, Action, Resource, and optionally Condition.

2. Step 2: Identify key for permission type

   The key that specifies whether to allow or deny is "Effect".

3. Final Answer:

   "Effect" -> Option D

4. Quick Check:

   Effect key = permission type [OK]

Hint: Effect key sets allow or deny in IAM policy [OK]

Common Mistakes:

• Using "Permission" instead of "Effect"
• Confusing "Action" with permission type
• Mistaking "Resource" for effect

3. Given this IAM policy statement snippet:

{
  "Effect": "Allow",
  "Action": "s3:ListBucket",
  "Resource": "arn:aws:s3:::example-bucket"
}

What permission does this statement grant?

medium

A. Allows listing the bucket itself

B. Allows listing objects inside the bucket

C. Allows deleting the bucket

D. Allows uploading objects to the bucket

Solution

1. Step 1: Understand the Action "s3:ListBucket"

   This action allows listing the bucket itself and its metadata, not the objects inside.

2. Step 2: Match Resource and Action

   The resource is the bucket ARN, so permission is to list the bucket (its properties), not the objects inside the bucket.

3. Final Answer:

   Allows listing the bucket itself -> Option A

4. Quick Check:

   s3:ListBucket = list bucket (not objects) [OK]

Hint: s3:ListBucket lists the bucket, not objects inside [OK]

Common Mistakes:

• Confusing ListBucket with listing objects inside the bucket
• Assuming permission to delete or upload
• Ignoring the resource ARN level

4. Identify the error in this IAM policy statement:

{
  "Effect": "Allow",
  "Action": ["ec2:StartInstances", "ec2:StopInstances"],
  "Resource": "*",
  "Condition": {
    "StringEquals": {
      "ec2:Region": "us-west-2"
    }
  }
}

medium

A. The Condition key is not valid for EC2 actions

B. The Condition key should be inside the Action key

C. The policy is valid and has no errors

D. The Resource value "*" is not allowed for these actions

Solution

1. Step 1: Check Condition usage with EC2 actions

   EC2 supports conditions like StringEquals on ec2:Region to restrict actions by region.

2. Step 2: Verify Resource and structure

   Resource "*" is valid for EC2 start/stop actions because they apply to instances across resources.

3. Final Answer:

   The policy is valid and has no errors -> Option C

4. Quick Check:

   Condition on ec2:Region with Resource "*" is valid [OK]

Hint: Conditions can restrict actions by region or other keys [OK]

Common Mistakes:

• Thinking Condition is invalid for EC2
• Assuming Resource "*" is always wrong
• Misplacing Condition inside Action

5. You want to create an IAM policy that allows a user to read objects only from a specific S3 bucket named "my-data-bucket" but denies deleting any objects. Which policy statement correctly achieves this?

hard

A. {
"Effect": "Allow",
"Action": ["s3:GetObject"],
"Resource": "arn:aws:s3:::my-data-bucket/*"
}

B. {
"Effect": "Allow",
"Action": ["s3:GetObject", "s3:DeleteObject"],
"Resource": "arn:aws:s3:::my-data-bucket/*"
}

C. {
"Effect": "Deny",
"Action": "s3:DeleteObject",
"Resource": "arn:aws:s3:::my-data-bucket/*"
}

D. {
"Effect": "Allow",
"Action": "s3:*",
"Resource": "arn:aws:s3:::my-data-bucket"
}

Solution

1. Step 1: Identify required permissions

   The user needs permission to read objects only, which is "s3:GetObject" on the bucket's objects.

2. Step 2: Check for delete denial

   Not including "s3:DeleteObject" means no delete permission is granted. Explicit deny is not required if no allow exists.

3. Step 3: Validate resource ARN

   The resource must include "/*" to specify objects inside the bucket, not the bucket itself.

4. Final Answer:

   Allow s3:GetObject on objects in my-data-bucket only -> Option A

5. Quick Check:

   Allow read only, no delete = { "Effect": "Allow", "Action": ["s3:GetObject"], "Resource": "arn:aws:s3:::my-data-bucket/*" } [OK]

Hint: Allow only needed actions; omit delete to deny it [OK]

Common Mistakes:

• Allowing delete by mistake
• Using bucket ARN without /* for objects
• Using wildcard s3:* granting too many permissions