Context

A couple of days ago I was helping a friend to deploy an AspNet Core application on Heroku and to be able to do it we knew that Docker was necessary. Create the image and start the application locally wasn’t a big issue but, some cloud platforms for running containers require your application to listen to a PORT environment variable so, when they create the container, all their internal bindings are done properly. Some providers I tested that have this requirement are Heroku and GCP Cloud Run.