EdgeX Source

Kuiper provides built-in support for EdgeX source stream, which can subscribe the message from EdgeX message bus (opens new window) and feed into the Kuiper streaming process pipeline.

Stream definition for EdgeX

EdgeX already defines data types in value descriptors (opens new window), so it’s recommeded to use schema-less stream definition in EdgeX source as in below.

# cd $kuiper_base
# bin/kuiper CREATE STREAM demo'() with(format="json", datasource="demo" type="edgex")'

EdgeX source will try to get the data type of a field,

• convert to releated data type if field of a type can be found in value descriptors service;
• or keep original value if field of a type can not be found in value descriptors service;
• or if failed to conver the value, then the value will be dropped, and a warning message print in the log;

The types defined in EdgeX value descriptors will be converted into related data types that supported in Kuiper.

Boolean

If Type value of ValueDescriptor is Bool, then Kuiper tries to convert to boolean type. Following values will be converted into true.

• “1”, “t”, “T”, “true”, “TRUE”, “True”

Following will be converted into false.

• “0”, “f”, “F”, “false”, “FALSE”, “False”

Bigint

If Type value of ValueDescriptor is INT8 , INT16, INT32, INT64,UINT , UINT8 , UINT16 , UINT32 , UINT64 then Kuiper tries to convert to Bigint type.

Float

If Type value of ValueDescriptor is FLOAT32, FLOAT64, then Kuiper tries to convert to Float type.

String

If Type value of ValueDescriptor is String, then Kuiper tries to convert to String type.

Boolean array

Bool array type in EdgeX will be converted to boolean array.

Bigint array

All of INT8 , INT16, INT32, INT64,UINT , UINT8 , UINT16 , UINT32 , UINT64 array types in EdgeX will be converted to Bigint array.

Float array

All of FLOAT32, FLOAT64 array types in EdgeX will be converted to Float array.

Global configurations

The configuration file of EdgeX source is at $kuiper/etc/sources/edgex.yaml. Below is the file format.

#Global Edgex configurations
default:
  protocol: tcp
  server: localhost
  port: 5573
  topic: events
  serviceServer: http://localhost:48080
#  optional:
#    ClientId: client1
#    Username: user1
#    Password: password

Use can specify the global EdgeX settings here. The configuration items specified in default section will be taken as default settings for all EdgeX source.

protocol

The protocol connect to EdgeX message bus, default value is tcp.

server

The server address of EdgeX message bus, default value is localhost.

port

The port of EdgeX message bus, default value is 5573.

topic

The topic name of EdgeX message bus, default value is events.

serviceServer

The base service address for getting value descriptors, the value of serviceServer will be concatenated to /api/v1/valuedescriptor to get all of value descriptors of EdgeX server.

type

The EdgeX message bus type, currently two types of message buses are supported. If specified other values, then will use the default zero value.

• zero: Use ZeroMQ as EdgeX message bus.
• mqtt: Use the MQTT broker as EdgeX message bus.

optional

If MQTT message bus is used, some other optional configurations can be specified. Please notice that all of values in optional are string type, so values for these configurations should be string - such as KeepAlive: "5000". Below optional configurations are supported, please check MQTT specification for the detailed information.

• ClientId

• Username

• Password

• Qos

• KeepAlive

• Retained

• ConnectionPayload

• CertFile

• KeyFile

• CertPEMBlock

• KeyPEMBlock

• SkipCertVerify

Override the default settings

In some cases, maybe you want to consume message from multiple topics from message bus. Kuiper supports to specify another configuration, and use the CONF_KEY to specify the newly created key when you create a stream.

#Override the global configurations
demo1: #Conf_key
  protocol: tcp
  server: 10.211.55.6
  port: 5571
  topic: events

If you have a specific connection that need to overwrite the default settings, you can create a customized section. In the previous sample, we create a specific setting named with demo1. Then you can specify the configuration with option CONF_KEY when creating the stream definition (see stream specs for more info).

Sample

create stream demo1() WITH (FORMAT="JSON", type="edgex", CONF_KEY="demo1");

The configuration keys used for these specific settings are the same as in default settings, any values specified in specific settings will overwrite the values in default section.