Using IAM role to send SMS via SNS

sms_via_sns_using_iam_role.txt

1. create sns topic

2. Under Amazon SNS > Text messaging (SMS) 

Add your phone number and verify it with otp.

reason:
by default SMS is in sandbox mode: https://docs.aws.amazon.com/sns/latest/dg/sns-sms-sandbox.html
Need to create a support ticket to "Exit SMS Sandbox" :weird: which only allows us to send sms on verified number.

2.1 Create a SMS subscirption with thant number, use SMS protocol

3. Create iam role with policy:
```json
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": "sns:Publish",
            "Resource": "arn:aws:sns:us-east-1:xxx:SMS"
        }
    ]
}

```

4. create iam role and attach the policy above
5. Install awscli and test this policy in action
```
aws sts get-caller-identity > /tmp/id; aws sns publish --phone-number +97712345 --message "this is cool $(cat /tmp/id)" --region us-east-1
```