aws-cdk.aws-iotevents 1.174.0

The CDK Construct Library for AWS::IoTEvents

AWS::IoTEvents Construct Library

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All classes with the Cfn prefix in this module (CFN Resources) are always stable and safe to use.

The APIs of higher level constructs in this module are experimental and under active development. They are subject to non-backward compatible changes or removal in any future version. These are not subject to the Semantic Versioning model and breaking changes will be announced in the release notes. This means that while you may use them, you may need to update your source code when upgrading to a newer version of this package.

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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 aws_cdk.aws_iotevents as 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 aws_cdk.aws_iotevents as iotevents
import aws_cdk.aws_iotevents_actions as actions
import aws_cdk.aws_lambda as lambda_

# func: lambda.IFunction


input = iotevents.Input(self, "MyInput",
    input_name="my_input",  # optional
    attribute_json_paths=["payload.deviceId", "payload.temperature"]
)

warm_state = iotevents.State(
    state_name="warm",
    on_enter=[iotevents.Event(
        event_name="test-enter-event",
        condition=iotevents.Expression.current_input(input),
        actions=[actions.LambdaInvokeAction(func)]
    )],
    on_input=[iotevents.Event( # optional
        event_name="test-input-event",
        actions=[actions.LambdaInvokeAction(func)])],
    on_exit=[iotevents.Event( # optional
        event_name="test-exit-event",
        actions=[actions.LambdaInvokeAction(func)])]
)
cold_state = iotevents.State(
    state_name="cold"
)

# transit to coldState when temperature is less than 15
warm_state.transition_to(cold_state,
    event_name="to_coldState",  # optional property, default by combining the names of the States
    when=iotevents.Expression.lt(
        iotevents.Expression.input_attribute(input, "payload.temperature"),
        iotevents.Expression.from_string("15")),
    executing=[actions.LambdaInvokeAction(func)]
)
# transit to warmState when temperature is greater than or equal to 15
cold_state.transition_to(warm_state,
    when=iotevents.Expression.gte(
        iotevents.Expression.input_attribute(input, "payload.temperature"),
        iotevents.Expression.from_string("15"))
)

iotevents.DetectorModel(self, "MyDetectorModel",
    detector_model_name="test-detector-model",  # optional
    description="test-detector-model-description",  # optional property, default is none
    evaluation_method=iotevents.EventEvaluation.SERIAL,  # optional property, default is iotevents.EventEvaluation.BATCH
    detector_key="payload.deviceId",  # optional property, default is none and single detector instance will be created and all inputs will be routed to it
    initial_state=warm_state
)

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

import aws_cdk.aws_iam as iam
import aws_cdk.aws_iotevents as iotevents

# grantable: iam.IGrantable

input = iotevents.Input.from_input_name(self, "MyInput", "my_input")

input.grant_write(grantable)