device-rest-go

EdgeX device service for REST protocol

This device service provides easy way for 3'rd party applications, such as Point of Sale, CV Analytics, etc., to push data into EdgeX via the REST protocol.

Runtime Requisite

• core-data
  • Mongo or Redis DB
• core-metadata

REST Endpoints

This device service creates the additional parametrized REST endpoint:

/ap1/vi/resource/{deviceName}/{resourceName}

• deviceName refers to the device defined in a device profile and the configuration.toml.
• resourceNamerefers to the device resource defined in the device profile that deviceName references.

The data, text or binary, posted to this endpoint is type validated and type casted (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 casted to the specific type of the specified device resource once it passes type validation.

Configuration

This device service use the standard configuration defined by the Device SDK.

The DeviceList configuration is standard except that the DeviceList.Protocols can be empty. The following is a sample DeviceList that works with the sample device profiles referenced below.

[[DeviceList]]
  Name = "sample-json"
  Profile = "sample-json"
  Description = "RESTful Device that sends in JSON data"
  Labels = [ "rest", "json" ]
  [DeviceList.Protocols]
    [DeviceList.Protocols.other]
[[DeviceList]]
  Name = "sample-binary"
  Profile = "sample-binary"
  Description = "RESTful Device that sends in binary data"
  Labels = [ "rest", "binary" ]
  [DeviceList.Protocols]
    [DeviceList.Protocols.other]    
[[DeviceList]]
  Name = "sample-numbers"
  Profile = "sample-numbers"
  Description = "RESTful Device that sends in number data"
  Labels = [ "rest", "float", "int" ]
  [DeviceList.Protocols]
    [DeviceList.Protocols.other]

Device Profile

As with all device services the device profile is where the Device Name, Device Resources and Device Commands are define. The parameterized REST endpoint described above references these definitions. Each Device has it's own device profile. There are three sample device profiles that define the devices referenced in the above sample configuration.

• sample-binary-device
• sample-json-device
• sample-numbers-device

Note: ThecoreCommands section is omitted since this device service does not support Commanding. See below for details.

Note: The deviceCommands section only requires the get operations.

Commanding

The current implementation is meant for one-way communication into EdgeX. If future use cases determine that commanding, i.e. two-communication, is desirable it can be added then.

AutoEvents

Since Commanding is not implemented, specifying AutoEvents in the configuration will result in errors. Thus AutoEvents should not be specified in the configuration.

Installation and Execution

make build
make run

Build docker image

make docker