Azure Service Discovery Can't find MSI endpoint

[mac m]

I am trying to setup Azure Service Discovery, but have hit an issue.  Trying to use a managed identity i keep getting the following error: StatusCode=0 -- Original Error: the MSI endpoint is not available. Failed HTTP request to MSI endpoint.  

My config: 

scrape_configs:

- job_name: service-azure

  azure_sd_configs:

    - environment: AzurePublicCloud

      authentication_method: ManagedIdentity

      subscription_id: xxxx

      port: 9101

I have tried using both user created and system assigned identity, with Reader role over the subscription with no luck.  I'm not sure if a different role is needed or if i am missing some sort of configuration.