As @uknth says, Docker will not scale magically by itself - it's merely the underlying container technology, so you would need something on top to manage scalability, whether it's your own code or something else. I'm not sure you would gain any instant benefits by moving away from Azure etc.

WAR files in Java can be seen as a "container" for Java applications, although that only works for Java, if you want to use the same process for Java and PHP applications, you need something that's standard between the two technologies, Docker gives you this - it allows you to package your application into a common format.

If you're just using .NET and Azure is taking care of everything, then not much benefits of using Docker. If you're mixing different versions of .NET and other technologies, then you might benefit from Docker. Also, if you want to run your workload on something like Kubernetes or Beanstalk, you'll be forced to package your applications in Docker containers.

• Rapid CI
• Rapid Development, as environment isn't a factor to consider, it will be same at all phases, i.e. from developer's machine to production server.
• Development effort is consistent and doesn't require you to add any additional libraries to run on various platforms.
• Check out Kubernetes or Core OS. It solves the problem of auto-scaling and HA.