Support running HotROD as multiple processes

[yurishkuro]

Requirement - what kind of business use case are you trying to solve?

As was raised in #939 (comment), when one of the ports used by HotROD is already taken on the host, there's no real way to run HotROD from executables (only from Docker image).

Problem - what in Jaeger blocks you from solving the requirement?

While the HotROD allows running each of the microservices separately, it does not provide the ability to configure their ports so that each component can find the other components.

Proposal - what do you suggest to solve the problem or improve the existing situation?

Add command line flags for port number for each of the microservices in HotROD.

[cboornaz17]

I'd like to give this one a go. Could you give a little more insight into how exactly you'd like the flags to function?

[yurishkuro]

@cboornaz17 I think the simplest way is to register 4 new flags for each of the microservices that can specify the port number for their servers. That would still mean they have to run on the same host, or we'd need 4 more flags to specify the host:port for each service.