App Service Environment Detection for Production Mode

[seantleonard]

Why make this change?

• Closes Authentication Enhancement -> App Service Environment Check #596
  • Check to prevent users from accidentally hosting the engine in Production mode with AppService set as the authentication provider when the environment is NOT AppService.
• In a real App Service environment, the following environment variables will be present:
  • WEBSITE_AUTH_ENABLED with value true
  • APPSERVICESAUTH_IDENTITYPROVIDER_ENVVAR with value such as AzureActiveDirectory

What is this change?

• Add environment variable checks using abridged version of Microsoft.Identity.Web code: https://github.com/AzureAD/microsoft-identity-web/blob/4085a499afb8be6e02c5d24182cbdbc5a35a4031/src/Microsoft.Identity.Web/AppServicesAuth/AppServicesAuthenticationInformation.cs

How was this tested?

• Integration Tests
• Unit Tests

[Aniruddh25]

LGTM!

[Aniruddh25]

While this is good to merge, I think the issue that this is closing has a misleading heading: SWA Environment Check. As far as I understand, we are NOT doing any environment checks for SWA but this is for AppService in a self hosted scenario.

[ayush3797]

LGTM!