title: Call AWS Lambda from Aurora RDS Stored Procedure Permissions Issue
body: <p>I've created a few Lambdas in AWS, and an Aurora RDS (publicly available). I couldn't execute lambdas (via <code>call mysql.lambda_async</code>).</p>
  
  <p>When I tried that I got the error <code>ERROR 1873: 1873: Lambda API returned error: Missing Credentials: Cannot instantiate Lambda Client</code>.</p>
  
  <p>I tried attaching an IAM role called aurora-lambdas where I set full access to RDS and Lambdas and a trusted relationship between those services, but after trying various configurations I still get the issue.</p>
  
  <p>Do someone have successfully executed an AWS Lambda from RDS? Thanks :)</p>