Mapping MessageAttributes using SNS

[bryce-palmer]

We are attempting to publish messages to SNS via this API Gateway proxy plugin, but are running into issues mapping MessageAttributes, which is stopping us from filtering.

We are currently posting messages with a JSON body l like this:

{
  "Type":"Notification",
  "Message":{
     "entity_type":"node",
     "bundle":"article",
     "id":"20656",
     "uuid":"234653463463",
     "label":"How to be \u201cgreen\u201d at home",
     "langcode":"en",
     "isDefaultLanguage":true,
     "destinationURL":"https:\/\/google.com\/test",
     "source":"Source Here",
     "campaignId":"How to be \u201cgreen\u201d at home",
     "shortTitle":"How to be \u201cgreen\u201d at home",
     "audience":[
        "1018",
        "1019",
        "1020"
     ],
     "segment":[
        "4621"
     ],
     "jsonAPIRoute":"\/jsonapi\/node\/article\/057802183",
     "title":"How to be \u201cgreen\u201d at home",
     "status":false,
     "promote":false,
     "sticky":false,
     "path":{
        "alias":"\/test\/about-liberty\/test\/test\/how-to-be-green-at-home",
        "pid":"64871",
        "langcode":"en"
     },
     "publishedDate":"2038-01-19T03:14:07+0000"
  },
  "MessageAttributes":{
     "op":"UPDATE",
     "entity_type":"node",
     "bundle":"article"
  }
}

And this is all being injected into the Message field.

This then leads to the SNS message logging like this:

{
  Records: [
    {
      EventSource: 'aws:sns',
      EventVersion: '1.0',
      EventSubscriptionArn:
      'arn:aws:sns:us-east-1:23454324532:node-article-topic:2345432532',
      Sns: {
      Type: 'Notification',
      MessageId: '345243562',
      TopicArn: 'arn:aws:sns:us-east-1:32453253425:node-article-topic',
      Subject: null,
      Message: 'ABOVE JSON HERE IN FULL'
      MessageAttributes: {}
    }
  ]
}

We have experimented with requestParameters but have not yet been successful to map the message to the message and attributes accordingly for filtering. Is this not possible with SNS?