Accessing cross-account resources using AWS IoT rules

Configure AWS CLI using account A’s IAM user.

Create an IAM role that trusts AWS IoT rules engine, and attaches a policy that allows access to account B's Amazon SQS queue. See example commands and policy documents in Granting AWS IoT the required access.

To create a rule that is attached to a topic, run the create-topic-rule command.

aws iot create-topic-rule --rule-name myRule --topic-rule-payload file://./my-rule.json

The following is an example payload file with a rule that inserts all messages sent to the iot/test topic into the specified Amazon SQS queue. The SQL statement filters the messages and the role ARN grants AWS IoT permissions to add the message to the Amazon SQS queue.

{
	"sql": "SELECT * FROM 'iot/test'",
	"ruleDisabled": false,
	"awsIotSqlVersion": "2016-03-23",
	"actions": [
		{
			"sqs": {
				"queueUrl": "https://sqs.region.amazonaws.com/2222-2222-2222/ExampleQueue",
				"roleArn": "arn:aws:iam::1111-1111-1111:role/my-iot-role",
				"useBase64": false
			}
		}
	]
}

For more information about how to define an Amazon SQS action in an AWS IoT rule, see AWS IoT rule actions - Amazon SQS.

Configure AWS CLI using account B’s IAM user.

To give permissions for the Amazon SQS queue resource to account A, run the add-permission command.

aws sqs add-permission --queue-url https://sqs.region.amazonaws.com/2222-2222-2222/ExampleQueue --label SendMessagesToMyQueue --aws-account-ids 1111-1111-1111 --actions SendMessage

Configure AWS CLI using account A’s IAM user.

Create an IAM role that trusts AWS IoT rules engine, and attaches a policy that allows access to account B's Amazon SNS topic. For example commands and policy documents, see Granting AWS IoT the required access.

To create a rule that is attached to a topic, run the create-topic-rule command.

aws iot create-topic-rule --rule-name myRule --topic-rule-payload file://./my-rule.json

The following is an example payload file with a rule that inserts all messages sent to the iot/test topic into the specified Amazon SNS topic. The SQL statement filters the messages, and the role ARN grants AWS IoT permissions to send the message to the Amazon SNS topic.

{
	"sql": "SELECT * FROM 'iot/test'",
	"ruleDisabled": false,
	"awsIotSqlVersion": "2016-03-23",
	"actions": [
		{
			"sns": {
				"targetArn": "arn:aws:sns:region:2222-2222-2222:ExampleTopic",
				"roleArn": "arn:aws:iam::1111-1111-1111:role/my-iot-role"
			}
		}
	]
}

For more information about how to define an Amazon SNS action in an AWS IoT rule, see AWS IoT rule actions - Amazon SNS.

Configure AWS CLI using account B’s IAM user.

To give permission on the Amazon SNS topic resource to account A, run the add-permission command.

aws sns add-permission --topic-arn arn:aws:sns:region:2222-2222-2222:ExampleTopic --label Publish-Permission --aws-account-id 1111-1111-1111 --action-name Publish

Configure AWS CLI using account A’s IAM user.

Create an IAM role that trusts AWS IoT rules engine and attaches a policy that allows access to account B's Amazon S3 bucket. For example commands and policy documents, see Granting AWS IoT the required access.

To create a rule that is attached to your target S3 bucket, run the create-topic-rule command.

aws iot create-topic-rule --rule-name my-rule --topic-rule-payload file://./my-rule.json

The following is an example payload file with a rule that inserts all messages sent to the iot/test topic into the specified Amazon S3 bucket. The SQL statement filters the messages, and the role ARN grants AWS IoT permissions to add the message to the Amazon S3 bucket.

{
	"sql": "SELECT * FROM 'iot/test'",
	"ruleDisabled": false,
	"awsIotSqlVersion": "2016-03-23",
	"actions": [
		{
			"s3": {
				"bucketName": "amzn-s3-demo-bucket",
				"key": "${topic()}/${timestamp()}",
				"roleArn": "arn:aws:iam::1111-1111-1111:role/my-iot-role"
			}
		}
	]
}

For more information about how to define an Amazon S3 action in an AWS IoT rule, see AWS IoT rule actions - Amazon S3.

Configure AWS CLI using account B’s IAM user.

Create a bucket policy that trusts account A's principal.

The following is an example payload file that defines a bucket policy that trusts the principal of another account.

{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Sid": "AddCannedAcl",
			"Effect": "Allow",
			"Principal": {
				"AWS": [
					"arn:aws:iam::1111-1111-1111:root"
				]
			},
			"Action": "s3:PutObject",
			"Resource": "arn:aws:s3:::amzn-s3-demo-bucket/*"
		}
	]
}

For more information, see bucket policy examples.

To attach the bucket policy to the specified bucket, run the put-bucket-policy command.

aws s3api put-bucket-policy --bucket amzn-s3-demo-bucket --policy file://./amzn-s3-demo-bucket-policy.json

To make the cross-account access work, make sure you have the correct Block all public access settings. For more information, see Security Best Practices for Amazon S3.

Configure AWS CLI using account A’s IAM user.

Run the create-topic-rule command to create a rule that defines cross-account access to account B's Lambda function.

aws iot create-topic-rule --rule-name my-rule --topic-rule-payload file://./my-rule.json

The following is an example payload file with a rule that inserts all messages sent to the iot/test topic into the specified Lambda function. The SQL statement filters the messages and the role ARN grants AWS IoT permission to pass in the data to the Lambda function.

{
	"sql": "SELECT * FROM 'iot/test'",
	"ruleDisabled": false,
	"awsIotSqlVersion": "2016-03-23",
	"actions": [
		{
			"lambda": {
				"functionArn": "arn:aws:lambda:region:2222-2222-2222:function:example-function"
			}
		}
	]
}

For more information about how to define an AWS Lambda action in an AWS IoT rule, read AWS IoT rule actions - Lambda.

Configure AWS CLI using account B’s IAM user.

Run Lambda's add-permission command to give AWS IoT rules permission to activate the Lambda function. To run the following command, your IAM user should have permission to lambda:AddPermission action.

aws lambda add-permission --function-name example-function --region us-east-1 --principal iot.amazonaws.com --source-arn arn:aws:iot:region:1111-1111-1111:rule/example-rule --source-account 1111-1111-1111 --statement-id "unique_id" --action "lambda:InvokeFunction"

Options:

--principal

This field gives permission to AWS IoT (represented by iot.amazonaws.com) to call the Lambda function.

--source-arn

This field confirms that only arn:aws:iot:region:1111-1111-1111:rule/example-rule in AWS IoT triggers this Lambda function and no other rule in the same or different account can activate this Lambda function.

--source-account

This field confirms that AWS IoT activates this Lambda function only on behalf of the 1111-1111-1111 account.