Allow to run the Server without TLS

[alexanderkiel]

Is your feature request related to a problem? Please describe.
I our deployment environment, we like to run services without TLS enabled, behind a central TLS terminating load balancer like HAProxy. The reason for this decision is, that we believe that reverse proxies like HAProxy are more secure and reliable in doing horizontal things like TLS termination. Outsourcing TLS to a reverse proxy also makes the service implementing vertical solutions simpler and so easier to maintain and to configure. I also like to refer to The Twelve Factor App here.

Describe the solution you'd like
I like to have a way to configure a binary version of the FHIR server to run without TLS termination enabled.

Describe alternatives you've considered
An alternative is to run TLS behind the central TLS terminating load balancer to connect to the FHIR server. Although that would be possible, managing those certificates would mean a maintenance overhead.

Additional context
I assume an environment of lightweight services which conform to the rules laid out in The Twelve Factor App referenced above. That apps usually bring standalone HTTP endpoints and don't need application servers capable of things like TLS termination. I also assume to have something like Kubernetes as deployment target, were it is even easy to deploy a TLS terminating reverse proxy inside a pod, not exposing any HTTP traffic over the network. So I would be fine if my feature request will be refused, because the intended deployment targets of the FHIR server are different.

[prb112]

Chatted with Alexander on Zulip, and this is the elaboration of the discussion/issue.

[prb112]

Added fhir-server-webapp/target/fhir-server-notls.war to the build
#552

[prb112]

Assigned Lee as Reviewer.

[prb112]

Team agreed to remove the constraint.
PR #559

[prb112]

Constraint is removed.