In this article, I am going to show you how to use Terraform to create and configure an SNS topic that delivers SMS messages to a mobile phone number. In the second part, I will use the SnsPublishOperator to send messages from Airflow.
Define an SNS topic and subscription
First, we have to define a new aws_sns_topic resource in Terraform:
resource "aws_sns_topic" "send-sms" {
name = "send-sms"
}
After that, we have to add each recipient as a new SNS topic subscription:
resource "aws_sns_topic_subscription" "send-sms-recipient" {
topic_arn = aws_sns_topic.send-sms.arn
protocol = "sms"
endpoint = "phone number with country code"
}
In the end, we have to define an access policy that allows publishing messages:
data "aws_iam_policy_document" "sns_topic_policy" {
policy_id = "__default_policy_ID"
statement {
actions = [
"SNS:Publish"
]
effect = "Allow"
principals {
type = "AWS"
identifiers = ["aws_identifier_of_the_AWS_user_used_by_Airflow"]
}
resources = [
aws_sns_topic.send-sms.arn,
]
sid = "__default_statement_ID"
}
}
Sending SMS message from Airflow
To send a text message, we have to call the SnsPublishOperator inside an Airflow DAG. Of course, we can use templates to pass values to the message:
from airflow.contrib.operators.sns_publish_operator import SnsPublishOperator
send_sms = SnsPublishOperator(
task_id='send_sms',
target_arn='sns_topic_arn',
message='Here is the message. You can use the template variables to get values from XCom or DAG parameters.',
aws_conn_id='aws_connection_id'
)