software.amazon.lambda.powertools.cloudformation

Class AbstractCustomResourceHandler

java.lang.Object

software.amazon.lambda.powertools.cloudformation.AbstractCustomResourceHandler

All Implemented Interfaces:

com.amazonaws.services.lambda.runtime.RequestHandler<com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent,Response>

public abstract class AbstractCustomResourceHandler
extends java.lang.Object
implements com.amazonaws.services.lambda.runtime.RequestHandler<com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent,Response>

Handler base class providing core functionality for sending responses to custom CloudFormation resources after receiving some event. Depending on the type of event, this class either invokes the crete, update, or delete method and sends the returned Response object to the custom resource.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractCustomResourceHandler() Creates a new Handler that uses the default HTTP client for communicating with custom CloudFormation resources.
protected	AbstractCustomResourceHandler(software.amazon.awssdk.http.SdkHttpClient client) Creates a new Handler that uses the provided HTTP client for communicating with custom CloudFormation resources.

Method Summary

Modifier and Type	Method and Description
protected abstract Response	create(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event, com.amazonaws.services.lambda.runtime.Context context) Returns the response object to send to the custom CloudFormation resource upon its creation.
protected abstract Response	delete(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event, com.amazonaws.services.lambda.runtime.Context context) Returns the response object to send to the custom CloudFormation resource upon its deletion.
Response	handleRequest(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event, com.amazonaws.services.lambda.runtime.Context context) Generates the appropriate response object based on the event type and sends it as a response to the custom cloud formation resource using the URL provided within the event.
protected void	onSendFailure(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event, com.amazonaws.services.lambda.runtime.Context context, Response response, java.lang.Exception exception) Invoked when there is an error sending a response to the custom cloud formation resource.
protected abstract Response	update(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event, com.amazonaws.services.lambda.runtime.Context context) Returns the response object to send to the custom CloudFormation resource upon its modification.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractCustomResourceHandler

protected AbstractCustomResourceHandler()

Creates a new Handler that uses the default HTTP client for communicating with custom CloudFormation resources.

AbstractCustomResourceHandler

protected AbstractCustomResourceHandler(software.amazon.awssdk.http.SdkHttpClient client)

Creates a new Handler that uses the provided HTTP client for communicating with custom CloudFormation resources.

Parameters:

client - cannot be null

Method Detail

handleRequest

public final Response handleRequest(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event,
                                    com.amazonaws.services.lambda.runtime.Context context)

Generates the appropriate response object based on the event type and sends it as a response to the custom cloud formation resource using the URL provided within the event.

Specified by:

handleRequest in interface com.amazonaws.services.lambda.runtime.RequestHandler<com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent,Response>

Parameters:

event - custom resources create/update/delete event

context - lambda execution context

Returns:

potentially null response object sent to the custom resource

onSendFailure

protected void onSendFailure(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event,
                             com.amazonaws.services.lambda.runtime.Context context,
                             Response response,
                             java.lang.Exception exception)

Invoked when there is an error sending a response to the custom cloud formation resource. This method does not get called if there are errors constructing the response itself, which instead is handled by sending an empty FAILED response to the custom resource. This method will be invoked, however, if there is an error while sending the FAILED response.

The method itself does nothing but subclasses may override to provide additional logging or handling logic. All arguments provided are for contextual purposes.

Exceptions should not be thrown by this method.

Parameters:

event - the event

context - execution context

response - the response object that was attempted to be sent to the custom resource

exception - the exception caught when attempting to call the custom resource URL

create

protected abstract Response create(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event,
                                   com.amazonaws.services.lambda.runtime.Context context)

Returns the response object to send to the custom CloudFormation resource upon its creation. If this method returns null, then the handler will send a successful but empty response to the CloudFormation resource. If this method throws a RuntimeException, the handler will send an empty failed response to the resource.

Parameters:

event - an event of request type Create

context - execution context

Returns:

the response object or null

update

protected abstract Response update(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event,
                                   com.amazonaws.services.lambda.runtime.Context context)

Returns the response object to send to the custom CloudFormation resource upon its modification. If the method returns null, then the handler will send a successful but empty response to the CloudFormation resource. If this method throws a RuntimeException, the handler will send an empty failed response to the resource.

Parameters:

event - an event of request type Update

context - execution context

Returns:

the response object or null

delete

protected abstract Response delete(com.amazonaws.services.lambda.runtime.events.CloudFormationCustomResourceEvent event,
                                   com.amazonaws.services.lambda.runtime.Context context)

Returns the response object to send to the custom CloudFormation resource upon its deletion. If this method returns null, then the handler will send a successful but empty response to the CloudFormation resource. If this method throws a RuntimeException, the handler will send an empty failed response to the resource.

Parameters:

event - an event of request type Delete

context - execution context

Returns:

the response object or null