Device REST - Getting Started

Running Service

The simplest way to run all the required services is to use the Compose Builder tool from a terminal window

Clone https://github.com/edgexfoundry/edgex-compose/tree/main
Change to the compose-builder folder
Run the services
```
make run no-secty ds-rest
```

This runs, in non-secure mode, all the standard EdgeX services along with the Device Rest service.

Sample Device Profiles

The service contains the following sample Device Profiles as examples. This is where Device Resources and Device Commands are defined.

Name	Description
sample-numeric-device.yaml	Example of device type which can POST values for numeric resources
sample-json-device.yaml	Example of device type which can POST values for object resources
sample-image-device.yaml	Example of device type which can POST values for image resources
sample-2way-rest-device.yaml	Example of device type which supports commanding to read and set resources

Use these samples to determine the best way to module your REST device with a new Device Profile. Also see the Device Profiles section for more details about Device Profiles.

Sample Devices

The service contains the sample-devices.yaml devices as examples of device instances for the above Device Profiles.

This is where device instances are statically defined. Use these samples to determine the best way to define your REST Device instances. Also see the Device Definitions section for more details about Device Definitions.

REST Endpoints

Async

This device service creates the additional parametrized REST endpoint to receive async data. See API Reference for additional details. End devices will push async data to this endpoint.

The data, text or binary, posted to this endpoint is type validated and type cast (text data only) to the type defined by the specified device resource. The resulting value is then sent into EdgeX via the Device SDK's async values channel.

Note

When binary data is used the EdgeX event/reading is CBOR encoded by the Device SDK and the binary value in the reading isNOT be stored in the database by Core Data. The CBOR encoded event/reading, with the binary value, is published to the Message Bus for Application Services to consume.

Note

All non-binary data is consumed as text. The text is cast to the specific type of the specified device resource once it passes type validation.

See the Async Testing section for example on sending async data to this service

Device Commands

Device Commands received by this service are forwarded to the end device for processing. See the Device Commands section for details on Device Commands.

This device service reads the end device protocol parameters from the device's protocol properties to construct the URI in which to call on the end device.

Example REST protocol parameters found in definition

    protocols:
      REST:
        Host: 127.0.0.1
        Port: '5000'
        Path: api

The commandName is appended to the Path parameter (in example above) to construct the desired endpoint on the end device.

A GET command sends a new http GET request to the end device. The response received from end device is type validated and sent as the response to the GET command.

A SET command sends a new http PUT request to the end device containing the body from the received SET command. The end device response status code is sent in response to the SET command.

AutoEvents

Auto events are supported for resources on end devices that support commanding. See AutoEvents section for more details on enabling and using AutoEvents.