AWS Directory Services allows you to join AWS resources to Microsoft Active Directory. This includes Amazon Relational Database Service (RDS), Amazon FSx, Amazon Workspaces, Amazon Appstream 2.0, Amazon Connect, Amazon QuickSight, Amazon WorkDocs, Amazon WorkMail, and of course Amazon Elastic Compute Cloud (EC2) Windows instances. In addition, AWS recently announced the ability to Seamlessly Domain Join Linux EC2 Instances.

As I modernize .NET applications by moving to .NET 5 and Linux, I can continue to leverage Active Directory for credential management. Seamless domain join for EC2 Linux greatly simplifies the undifferentiated heavy lifting of configuring these architectures. This post will explore how to connect to RDS for SQL Server from a .NET 5 application running on EC2 Linux, using domain credentials.

When doing a customer demo, I often need a simple app. Generally I am discussing the infrastructure – Elastic Load Balancer, API Gateway, etc – and the application is unimportant. I have found that phpinfo is a great sample application because it shows the headers received by the server. This allows me to see x-forwarded-for headers, etc. On Windows, ASP.NET Tracing provides similar results. Keep in mind that these utilities expose a lot of info about your environment so use them wisely.

In the post, I will show you how to build a Linux container in Visual Studio running on a EC2 Windows Instance.

The AWS Toolkit for Visual Studio allows you to deploy your project to Elastic Container Service (ECS) Fargate and recently as a container image to AWS Lambda among other options. In both of these cases, you must build a Linux container from Visual Studio or the dotnet command line. If you are working in Visual Studio on Windows, Docker Desktop uses a Linux container running in Hyper-V to build the container. Unfortunately, Hyper-V does not run on EC2 Instances (though it will run on EC2 bare metal).

Cloud-Init is a set of Python scripts used to configure Linux instances when they boot in AWS. Cloud-Init is included on Ubuntu and Amazon Linux AMIs.

You can think of a Cloud Init script as a bare-bones Configuration Management solution like Chef or Puppet. A Cloud-Init script is passed as user data. If you have ever passed a shell script as user data, it was Cloud-Init that queried the meta-data service and executed the script. But, Cloud-Init offers a higher level syntax known as cloud-config.