title: How to get access token to pull Azure Monitor metrics for a specific subscription?
body: <p>We need to generate an AAD access token which can be used for a client to query Azure Monitor metrics (though Fluent API) for a specific subscription. So the requirements are:
  1. the token can only be used to query metrics for a specific subscription, but no others
  2. only can query metrics from Azure Monitoring (through ARM I believe)</p>
  
  <p>How can we:
  1. obtain the access token?
  2. For Azure Management Fluent SDK, how to use the token directly?</p>
  
  <p>Thanks!</p>