Alexa Custom Skill Device Discovery

I am new to Alexa skill set, I have a device which needs to be discovered by alexa. I'm confused by the device discovery functionality of Alexa SMART HOME SKILL API. I need some detailed information about how to connect a device which built by you (using raspberry pie) to let Alexa discover through Custom skill.

sample code or good guidelines is needed.

I understand the payload should be returned from device cloud (product manufacturer owns this). How do you ensure which device is with customer and the device is of correct customer?

Example payload is below..

"discoveredAppliances": [{
    "applianceId": "sample-1",
    "manufacturerName": "Sample Manufacturer",
    "modelName": "Sample Thermostat",
    "version": "1",
    "friendlyName": "Sample Thermostat",
    "friendlyDescription": "Thermostat by Sample Manufacturer",
    "isReachable": true,
     "actions": [
        "setTargetTemperature",
        "incrementTargetTemperature",
        "decrementTargetTemperature"
     ],
     "additionalApplianceDetails": {
     "extraDetail1": "This is a thermostat that is reachable"
    }
 }]

Can you explain the discoveredAppliances json object in detail? the logic behind generating these details for customer in device cloud?

via prasa_Andi