title: AWS SNS ought to trigger my lambda, but does not
body: <p>I have an AWS lambda function that I created via apex. I've also created a SNS topic and a subscription through terraform.</p>
  
  <p>My topic is: <code>arn:aws:sns:ap-southeast-1:178284945954:fetch_realm_auctions</code></p>
  
  <p>I have a subscription: <code>arn:aws:sns:ap-southeast-1:178284945954:fetch_realm_auctions:2da1d182-946d-4afd-91cb-1ed3453c5d86</code> with a <code>lambda</code> type and the endpoint is: <code>arn:aws:lambda:ap-southeast-1:178284945954:function:wowauctions_get_auction_data</code></p>
  
  <p>I've confirmed this is the correct function ARN. Everything seems wired up correctly:</p>
  
  <p><a href="https://i.stack.imgur.com/ivuzn.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ivuzn.png" alt="SNS picture"></a></p>
  
  <p>I trigger SNS manually:</p>
  
  <pre><code>aws sns publish 
    --topic-arn arn:aws:sns:ap-southeast-1:178284945954:fetch_realm_auctions 
    --message '{"endpoint": "https://us.api.battle.net", "realm": "spinebreaker"}'
  </code></pre>
  
  <p>It returns the message ID but no invocation happens. Why?</p>