AWS::IoTEvents Construct Library

AWS CDK v1 has reached End-of-Support on 2023-06-01. This package is no longer being updated, and users should migrate to AWS CDK v2.

For more information on how to migrate, see the Migrating to AWS CDK v2 guide.

AWS IoT Events enables you to monitor your equipment or device fleets for failures or changes in operation, and to trigger actions when such events occur.

Installation

Install the module:

$ npm i @aws-cdk/aws-iotevents

Import it into your code:

import * as iotevents from '@aws-cdk/aws-iotevents';

DetectorModel

The following example creates an AWS IoT Events detector model to your stack. The detector model need a reference to at least one AWS IoT Events input. AWS IoT Events inputs enable the detector to get MQTT payload values from IoT Core rules.

You can define built-in actions to use a timer or set a variable, or send data to other AWS resources. See also @aws-cdk/aws-iotevents-actions for other actions.

import * as iotevents from '@aws-cdk/aws-iotevents';
import * as actions from '@aws-cdk/aws-iotevents-actions';
import * as lambda from '@aws-cdk/aws-lambda';

declare const func: lambda.IFunction;

const input = new iotevents.Input(this, 'MyInput', {
  inputName: 'my_input', // optional
  attributeJsonPaths: ['payload.deviceId', 'payload.temperature'],
});

const warmState = new iotevents.State({
  stateName: 'warm',
  onEnter: [{
    eventName: 'test-enter-event',
    condition: iotevents.Expression.currentInput(input),
    actions: [new actions.LambdaInvokeAction(func)], // optional
  }],
  onInput: [{ // optional
    eventName: 'test-input-event',
    actions: [new actions.LambdaInvokeAction(func)],
  }],
  onExit: [{ // optional
    eventName: 'test-exit-event',
    actions: [new actions.LambdaInvokeAction(func)],
  }],
});
const coldState = new iotevents.State({
  stateName: 'cold',
});

// transit to coldState when temperature is less than 15
warmState.transitionTo(coldState, {
  eventName: 'to_coldState', // optional property, default by combining the names of the States
  when: iotevents.Expression.lt(
    iotevents.Expression.inputAttribute(input, 'payload.temperature'),
    iotevents.Expression.fromString('15'),
  ),
  executing: [new actions.LambdaInvokeAction(func)], // optional
});
// transit to warmState when temperature is greater than or equal to 15
coldState.transitionTo(warmState, {
  when: iotevents.Expression.gte(
    iotevents.Expression.inputAttribute(input, 'payload.temperature'),
    iotevents.Expression.fromString('15'),
  ),
});

new iotevents.DetectorModel(this, 'MyDetectorModel', {
  detectorModelName: 'test-detector-model', // optional
  description: 'test-detector-model-description', // optional property, default is none
  evaluationMethod: iotevents.EventEvaluation.SERIAL, // optional property, default is iotevents.EventEvaluation.BATCH
  detectorKey: 'payload.deviceId', // optional property, default is none and single detector instance will be created and all inputs will be routed to it
  initialState: warmState,
});

To grant permissions to put messages in the input, you can use the grantWrite() method:

import * as iam from '@aws-cdk/aws-iam';
import * as iotevents from '@aws-cdk/aws-iotevents';

declare const grantable: iam.IGrantable;
const input = iotevents.Input.fromInputName(this, 'MyInput', 'my_input');

input.grantWrite(grantable);