CLI: service and loadbalancer UX relationship is awkward

[diemonster]

Throughout Layer0's lifecycle, we've had discussions on how to improve the relationship between loadbalancers (ELBs) and services from the CLI. The workflow is currently:

• create a deploy (that has most of the ports you need already defined in it)
• create a loadbalancer with all ports again supplied on command line
• create a service that has to be tied specifically to the loadbalancer you just created

This workflow must be completed in order, as a service must have a loadbalancer already available at creation time.

While it would be better UX to simply derive the ELB configuration from a deploy, the problem is that an ELB's ports have a relationship that can't be obtained solely from a deploy / task definition. The relationship works out to be public elb port -> hostPort -> containerPort, and only the later two ports are defined in a deploy. As such, we have to force the user to supply that final mapping of public elb port -> hostPort.