title: Inaccessible DynamoDB host when running amplify mock
body: <p>I am using AWS Amplify to set up an AppSync GraphQL API. I have a schema with an @model annotation and I am trying to write a lambda resolver that will read/write to the DynamoDB table that @model generates. However, when I attempt to test locally using <code>amplify mock</code> my JS function throws</p>
  
  <pre><code>error { UnknownEndpoint: Inaccessible host: `dynamodb.us-east-1-fake.amazonaws.com'. This service may not be available in the `us-east-1-fake' region.
  </code></pre>
  
  <p>I can't seem to find much documentation around this use case at all (most examples of lambda resolvers read from other tables / APIs that are not part of the amplify app) so any pointers are appreciated. Is running this type of setup even supported or do I have to push to AWS in order to test?</p>