C# Cloud AWS - Day Four

Commands to Set Up SQS, SNS, and EventBridge

Note in Every command and URL being called there are fields that need to be replaced.

Example replacements (make sure to replace the curly brackets as well: don't keep curly brackets)

{studentName} - example ajdewilzin - this can be your name, independent of your login details

{region} - example eu-north-1

Steps

1. Create an SNS Topic:

aws sns create-topic --name {studentName}OrderCreatedTopic

If successful, you will see in your terminal a JSON response that includes "TopicArn": "....

Replace _topicArn in your Controller code with the generated TopicArn value from above.

2. Create an SQS Queue:

aws sqs create-queue --queue-name {studentName}OrderQueue

If successful, you will see in your terminal a JSON response that includes "QueueUrl": "some_aws_url.

Replace _queueUrl in your Controller code with the generated QueueUrl from the above command.

aws sns subscribe --topic-arn arn:aws:sns:{region}:637423341661:{studentName}OrderCreatedTopic --protocol sqs --notification-endpoint arn:aws:sqs:{region}:637423341661:{studentName}OrderQueue

You don't need to save the generated SubscriptionArn.

3. Create an EventBridge Event Bus:

aws events create-event-bus --name {StudentName}CustomEventBus --region {region}

4. Create an EventBridge Rule:

aws events put-rule --name {StudentName}OrderProcessedRule --event-pattern '{\"source\": [\"order.service\"]}' --event-bus-name {StudentName}CustomEventBus

If your terminal complains about double quotes, you might need to remove the backslash \ from the command above (and commands later on).

5. Subscribe the SQS Queue to the SNS Topic

aws sqs get-queue-attributes --queue-url https://sqs.{region}.amazonaws.com/637423341661/{studentName}OrderQueue --attribute-name QueueArn --region {region}

aws sns subscribe --topic-arn arn:aws:sns:{region}:637423341661:{studentName}OrderCreatedTopic --protocol sqs --notification-endpoint arn:aws:sqs:{region}:637423341661:{studentName}OrderQueue --region {region}

6. Grant SNS Permissions to SQS

In Bash/Unix terminals you can run this command:

aws sqs set-queue-attributes --queue-url https://sqs.{region}.amazonaws.com/637423341661/{studentName}OrderQueue --attributes '{"Policy":"{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Principal\":{\"AWS\":\"*\"},\"Action\":\"SQS:SendMessage\",\"Resource\":\"arn:aws:sqs:{region}:637423341661:{studentName}OrderQueue\",\"Condition\":{\"ArnEquals\":{\"aws:SourceArn\":\"arn:aws:sns:{region}:637423341661:{studentName}OrderCreatedTopic\"}}}]}"}' --region {region}

Core Exercise

1. Create a few orders using a RDS database. Orders to be saved in Database.
2. Update Process flag to false
3. Process orders and update the Total amount from QTY * AMOUNT
4. Update Process flag to true

Extension Exercise