SNS topics and subscriptions in AWS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an SNS topic named 'MyTopic'.

AWS

resource "aws_sns_topic" "example" {
  name = "[1]"
}

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

ATopicName

BMyTopic

CSNSExample

DExampleTopic

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different topic name than requested.

Leaving the name blank.

The name attribute sets the SNS topic's name. Here, it should be 'MyTopic'.

2fill in blank

medium

Complete the code to subscribe an email endpoint to the SNS topic.

AWS

resource "aws_sns_topic_subscription" "example" {
  topic_arn = aws_sns_topic.example.arn
  protocol  = "[1]"
  endpoint  = "[e-mail]"
}

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

Aemail

Blambda

Csms

Dhttp

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'sms' or 'http' instead of 'email' for email endpoints.

Misspelling the protocol string.

The protocol for email subscriptions must be set to 'email'.

3fill in blank

hard

Fix the error in the subscription code by completing the missing attribute.

AWS

resource "aws_sns_topic_subscription" "example" {
  topic_arn = aws_sns_topic.example.arn
  protocol  = "email"
  [1] = "[e-mail]"
}

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

Atarget

Baddress

Curl

Dendpoint

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'url' or 'address' instead of 'endpoint'.

Omitting the endpoint attribute.

The correct attribute to specify the destination for the subscription is endpoint.

4fill in blank

hard

Fill both blanks to create an SNS topic with display name and subscribe an SMS endpoint.

AWS

resource "aws_sns_topic" "example" {
  name         = "[1]"
  display_name = "[2]"
}

resource "aws_sns_topic_subscription" "sms_sub" {
  topic_arn = aws_sns_topic.example.arn
  protocol  = "sms"
  endpoint  = "[phone]"
}

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

AAlertsTopic

BMyTopic

CAlerts

DNotification

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping name and display_name values.

Using incorrect names.

The name is 'AlertsTopic' and the display_name is 'Alerts'.

5fill in blank

hard

Fill all three blanks to create an SNS topic, subscribe an HTTP endpoint, and set the subscription's raw message delivery.

AWS

resource "aws_sns_topic" "example" {
  name = "[1]"
}

resource "aws_sns_topic_subscription" "http_sub" {
  topic_arn            = aws_sns_topic.example.arn
  protocol             = "[2]"
  endpoint             = "https://example.com/notify"
  raw_message_delivery = [3]
}

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

AWebhookTopic

Bhttp

Ctrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'false' for raw_message_delivery when true is needed.

Using wrong protocol like 'email' for HTTP endpoint.

The topic name is 'WebhookTopic', protocol is 'http', and raw_message_delivery is set to true to send the message as-is.

Practice

1. What is the main purpose of an SNS topic in AWS?

easy

A. To store files and documents securely

B. To act as a message hub where messages are sent and distributed

C. To run virtual servers in the cloud

D. To manage user permissions and access

Solution

1. Step 1: Understand SNS topic role

   An SNS topic is like a message board where messages are posted for others to receive.

2. Step 2: Compare options to SNS function

   Only To act as a message hub where messages are sent and distributed describes a message hub, which matches SNS topic's purpose.

3. Final Answer:

   To act as a message hub where messages are sent and distributed -> Option B

4. Quick Check:

   SNS topic = message hub [OK]

Hint: SNS topics distribute messages to subscribers [OK]

Common Mistakes:

• Confusing SNS topics with storage services
• Thinking SNS manages servers
• Mixing SNS with user access control

2. Which of the following is the correct way to subscribe an email endpoint to an SNS topic using AWS CLI?

easy

A. aws sns subscribe --subscription-arn arn:aws:sns:us-east-1:123456789012:MyTopic --protocol email --notification-endpoint [e-mail]

B. aws sns subscribe --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --notification-endpoint [e-mail]

C. aws sns subscribe --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --protocol email --notification-endpoint [e-mail]

D. aws sns subscribe --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --protocol email --endpoint [e-mail]

Solution

1. Step 1: Review AWS CLI subscribe syntax

   The correct command uses 'aws sns subscribe' with '--topic-arn', '--protocol', and '--endpoint' parameters.

2. Step 2: Check option correctness

   The correct command is 'aws sns subscribe --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --protocol email --endpoint [e-mail]'. Distractors use incorrect parameters like --notification-endpoint, miss --protocol, or use --subscription-arn.

3. Final Answer:

   aws sns subscribe --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --protocol email --endpoint [e-mail] -> Option D

4. Quick Check:

   Correct CLI syntax = aws sns subscribe --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --protocol email --endpoint [e-mail] [OK]

Hint: Use --protocol and --endpoint with aws sns subscribe [OK]

Common Mistakes:

• Using wrong parameter names like --notification-endpoint instead of --endpoint
• Missing the --protocol flag
• Confusing topic ARN with subscription ARN

3. Given this Python code using boto3, what will be the output if the subscription is successful?

import boto3
sns = boto3.client('sns')
response = sns.subscribe(
    TopicArn='arn:aws:sns:us-east-1:123456789012:MyTopic',
    Protocol='email',
    Endpoint='[e-mail]'
)
print(response['SubscriptionArn'])

medium

A. 'pending confirmation' string indicating subscription needs confirmation

B. An error message about missing permissions

C. The ARN of the SNS topic

D. The ARN of the new subscription if confirmed

Solution

1. Step 1: Understand SNS email subscription behavior

   Email subscriptions require the user to confirm by clicking a link. Until then, the SubscriptionArn is 'pending confirmation'.

2. Step 2: Analyze the printed output

   The code prints response['SubscriptionArn'], which will be 'pending confirmation' until user confirms.

3. Final Answer:

   'pending confirmation' string indicating subscription needs confirmation -> Option A

4. Quick Check:

   Email subscription = pending confirmation [OK]

Hint: Email subscriptions show 'pending confirmation' until user confirms [OK]

Common Mistakes:

• Expecting immediate subscription ARN without confirmation
• Confusing topic ARN with subscription ARN
• Assuming no confirmation needed for email protocol

4. You wrote this AWS CLI command to subscribe an HTTP endpoint but get an error:

aws sns subscribe --topic-arn arn:aws:sns:us-east-1:123456789012:MyTopic --protocol http --notification-endpoint http://example.com/notify

What is the most likely cause of the error?

medium

A. The HTTP endpoint URL must use HTTPS, not HTTP

B. The topic ARN is invalid

C. The protocol should be 'https' instead of 'http'

D. The notification endpoint URL is missing a trailing slash

Solution

1. Step 1: Check protocol requirements for HTTP endpoints

   AWS SNS requires HTTP endpoints to use HTTPS for security; HTTP URLs cause errors.

2. Step 2: Validate the given URL and protocol

   The URL uses 'http://' which is not allowed; it must be 'https://'.

3. Final Answer:

   The HTTP endpoint URL must use HTTPS, not HTTP -> Option A

4. Quick Check:

   HTTP endpoints require HTTPS URL [OK]

Hint: Use HTTPS URLs for HTTP/HTTPS SNS subscriptions [OK]

Common Mistakes:

• Assuming HTTP URLs are accepted
• Thinking trailing slash matters
• Confusing protocol parameter values

5. You want to send a notification to multiple endpoints: an email, an SMS number, and a Lambda function. How should you configure SNS to achieve this?

hard

A. Send messages directly to each endpoint without using SNS topics

B. Create separate SNS topics for each endpoint type and publish messages to all

C. Create one SNS topic and subscribe all three endpoints to it

D. Use only email and SMS subscriptions; Lambda cannot subscribe to SNS

Solution

1. Step 1: Understand SNS subscription flexibility

   An SNS topic can have multiple subscriptions of different protocols (email, SMS, Lambda).

2. Step 2: Choose the simplest and best practice approach

   Using one topic with multiple subscriptions is efficient and standard practice.

3. Final Answer:

   Create one SNS topic and subscribe all three endpoints to it -> Option C

4. Quick Check:

   One topic, multiple subscriptions = Create one SNS topic and subscribe all three endpoints to it [OK]

Hint: One SNS topic can have many different subscriptions [OK]

Common Mistakes:

• Thinking Lambda cannot subscribe to SNS
• Creating multiple topics unnecessarily
• Sending messages directly without SNS