How do I specify the port in my Linux container?
App Service has no control about which port your container listens on. What it does need is to know which port to forward requests to. If your container listens to port 80 or 8080, App Service is able to automatically detect it. If it listens to any other port, you need to set the WEBSITES_PORT app setting to the port number, and App Service forwards requests to that port in the container.