Lightpath as a Service

[ZLLentz]

Expected Behavior

Built-in mechanism for running a lightpath server process that loads a beamline and responds to requests from various clients about the state of the beam. This could have multiple interfaces that could be enabled/disabled in the server configuration, for example:

• json blob via http requests
• EPICS PVs via caproto
• PVA PVs via ???

Current Behavior

No such service, though an IOC has been proposed before in #99

Context

These could be used for smaller programs that don't have full knowledge of the beamline to get information about localized beam status. Consider typhos for example, which could display whether or not there is beam at a particular mirror, without having a giant screen open to cross-reference or needing to load a full lightpath on the client.