Filtering AWS SNS messages by attribute value but only if attribute is present

Question

I would like to know how I can create a filtering policy for AWS SNS subscription that would check a message attribute value but only if that attribute is present. By default if I check an attribute value but attribute is not present message is ignored e.g:

"customer_interests": ["paintball"]

I also found this for attribute presence checking:

"customer_interests": [{"exists": true}]

But I'm not sure how to combine this two checks into a single policy.

I've tried the obvious thing:

{
   "customer_interests": [{"exists": false}, "paintball"]
}

but it doesn't work.

Answer 1

i have tried the following thing ( your obvious thing ) and it worked for me, i didn't have to even wait for 15 minutes (clearly eventual consistency is not the issue )

Used the following policy

{
  "customer_interests": [
    {
      "exists": false
    },
    "paintball"
  ]
}

• Created a sns topic with email-based subscription
• added filter policy to subscriber

tried with three use case

Case 1

• message hello
• attribute type string
• atrribute name customer_interests
• atrribute value paintball
• status recieved

Case 3

• message hello
• attribute type string
• atrribute name customer_interests
• atrribute value xyz
• status not recieved

Case 3

• message hello
• attribute type string
• atrribute name jatin
• atrribute value test
• status recieved