README
¶
Amazon Lambda Destinations Library
This library provides constructs for adding destinations to a Lambda function.
Destinations can be added by specifying the onFailure
or onSuccess
props when creating a function or alias.
Destinations
The following destinations are supported
- Lambda function
- SQS queue - Only standard SQS queues are supported for failure destinations, FIFO queues are not supported.
- SNS topic
- EventBridge event bus
- S3 bucket
Example with a SNS topic for successful invocations:
// An sns topic for successful invocations of a lambda function
import sns "github.com/aws/aws-cdk-go/awscdk"
myTopic := sns.NewTopic(this, jsii.String("Topic"))
myFn := lambda.NewFunction(this, jsii.String("Fn"), &FunctionProps{
Runtime: lambda.Runtime_NODEJS_LATEST(),
Handler: jsii.String("index.handler"),
Code: lambda.Code_FromAsset(path.join(__dirname, jsii.String("lambda-handler"))),
// sns topic for successful invocations
OnSuccess: destinations.NewSnsDestination(myTopic),
})
Example with a SQS queue for unsuccessful invocations:
// An sqs queue for unsuccessful invocations of a lambda function
import sqs "github.com/aws/aws-cdk-go/awscdk"
deadLetterQueue := sqs.NewQueue(this, jsii.String("DeadLetterQueue"))
myFn := lambda.NewFunction(this, jsii.String("Fn"), &FunctionProps{
Runtime: lambda.Runtime_NODEJS_LATEST(),
Handler: jsii.String("index.handler"),
Code: lambda.Code_FromInline(jsii.String("// your code")),
// sqs queue for unsuccessful invocations
OnFailure: destinations.NewSqsDestination(deadLetterQueue),
})
See also Configuring Destinations for Asynchronous Invocation.
Invocation record
When a lambda function is configured with a destination, an invocation record is created by the Lambda service when the lambda function completes. The invocation record contains the details of the function, its context, and the request and response payloads.
The following example shows the format of the invocation record for a successful invocation:
{
"version": "1.0",
"timestamp": "2019-11-24T23:08:25.651Z",
"requestContext": {
"requestId": "c2a6f2ae-7dbb-4d22-8782-d0485c9877e2",
"functionArn": "arn:aws:lambda:sa-east-1:123456789123:function:event-destinations:$LATEST",
"condition": "Success",
"approximateInvokeCount": 1
},
"requestPayload": {
"Success": true
},
"responseContext": {
"statusCode": 200,
"executedVersion": "$LATEST"
},
"responsePayload": "<data returned by the function here>"
}
In case of failure, the record contains the reason and error object:
{
"version": "1.0",
"timestamp": "2019-11-24T21:52:47.333Z",
"requestContext": {
"requestId": "8ea123e4-1db7-4aca-ad10-d9ca1234c1fd",
"functionArn": "arn:aws:lambda:sa-east-1:123456678912:function:event-destinations:$LATEST",
"condition": "RetriesExhausted",
"approximateInvokeCount": 3
},
"requestPayload": {
"Success": false
},
"responseContext": {
"statusCode": 200,
"executedVersion": "$LATEST",
"functionError": "Handled"
},
"responsePayload": {
"errorMessage": "Failure from event, Success = false, I am failing!",
"errorType": "Error",
"stackTrace": [ "exports.handler (/var/task/index.js:18:18)" ]
}
}
Destination-specific JSON format
- For SNS/SQS (
SnsDestionation
/SqsDestination
), the invocation record JSON is passed as theMessage
to the destination. - For Lambda (
LambdaDestination
), the invocation record JSON is passed as the payload to the function. - For EventBridge (
EventBridgeDestination
), the invocation record JSON is passed as thedetail
in the PutEvents call. The value for the event fieldsource
islambda
, and the value for the event fielddetail-type
is either 'Lambda Function Invocation Result - Success' or 'Lambda Function Invocation Result – Failure', depending on whether the lambda function invocation succeeded or failed. The event fieldresource
contains the function and destination ARNs. See AWS Events for the different event fields. - For S3 (
S3Destination
), the invocation record json is stored as aFile
in the destination bucket. The path of a destination payload file in the configured bucket isaws/lambda/async/<function-name>/YYYY/MM/DD/YYYY-MM-DDTHH.MM.SS-<Random UUID>
.
Auto-extract response payload with lambda destination
The responseOnly
option of LambdaDestination
allows to auto-extract the response payload from the
invocation record:
// Auto-extract response payload with a lambda destination
var destinationFn function
sourceFn := lambda.NewFunction(this, jsii.String("Source"), &FunctionProps{
Runtime: lambda.Runtime_NODEJS_LATEST(),
Handler: jsii.String("index.handler"),
Code: lambda.Code_FromAsset(path.join(__dirname, jsii.String("lambda-handler"))),
// auto-extract on success
OnSuccess: destinations.NewLambdaDestination(destinationFn, &LambdaDestinationOptions{
ResponseOnly: jsii.Boolean(true),
}),
})
In the above example, destinationFn
will be invoked with the payload returned by sourceFn
(responsePayload
in the invocation record, not the full record).
When used with onFailure
, the destination function is invoked with the error object returned
by the source function.
Using the responseOnly
option allows to easily chain asynchronous Lambda functions without
having to deal with data extraction in the runtime code.
Documentation
¶
Index ¶
- func NewEventBridgeDestination_Override(e EventBridgeDestination, eventBus awsevents.IEventBus)
- func NewLambdaDestination_Override(l LambdaDestination, fn awslambda.IFunction, options *LambdaDestinationOptions)
- func NewS3Destination_Override(s S3Destination, bucket awss3.IBucket)
- func NewSnsDestination_Override(s SnsDestination, topic awssns.ITopic)
- func NewSqsDestination_Override(s SqsDestination, queue awssqs.IQueue)
- type EventBridgeDestination
- type LambdaDestination
- type LambdaDestinationOptions
- type S3Destination
- type SnsDestination
- type SqsDestination
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func NewEventBridgeDestination_Override ¶
func NewEventBridgeDestination_Override(e EventBridgeDestination, eventBus awsevents.IEventBus)
Default: - use the default event bus.
func NewLambdaDestination_Override ¶
func NewLambdaDestination_Override(l LambdaDestination, fn awslambda.IFunction, options *LambdaDestinationOptions)
func NewS3Destination_Override ¶ added in v2.168.0
func NewS3Destination_Override(s S3Destination, bucket awss3.IBucket)
func NewSnsDestination_Override ¶
func NewSnsDestination_Override(s SnsDestination, topic awssns.ITopic)
func NewSqsDestination_Override ¶
func NewSqsDestination_Override(s SqsDestination, queue awssqs.IQueue)
Types ¶
type EventBridgeDestination ¶
type EventBridgeDestination interface { awslambda.IDestination // Returns a destination configuration. Bind(_scope constructs.Construct, fn awslambda.IFunction, _options *awslambda.DestinationOptions) *awslambda.DestinationConfig }
Use an Event Bridge event bus as a Lambda destination.
If no event bus is specified, the default event bus is used.
Example:
// The code below shows an example of how to instantiate this type. // The values are placeholders you should change. import "github.com/aws/aws-cdk-go/awscdk" import "github.com/aws/aws-cdk-go/awscdk" var eventBus eventBus eventBridgeDestination := awscdk.Aws_lambda_destinations.NewEventBridgeDestination(eventBus)
func NewEventBridgeDestination ¶
func NewEventBridgeDestination(eventBus awsevents.IEventBus) EventBridgeDestination
Default: - use the default event bus.
type LambdaDestination ¶
type LambdaDestination interface { awslambda.IDestination // Returns a destination configuration. Bind(scope constructs.Construct, fn awslambda.IFunction, options *awslambda.DestinationOptions) *awslambda.DestinationConfig }
Use a Lambda function as a Lambda destination.
Example:
// Auto-extract response payload with a lambda destination var destinationFn function sourceFn := lambda.NewFunction(this, jsii.String("Source"), &FunctionProps{ Runtime: lambda.Runtime_NODEJS_LATEST(), Handler: jsii.String("index.handler"), Code: lambda.Code_FromAsset(path.join(__dirname, jsii.String("lambda-handler"))), // auto-extract on success OnSuccess: destinations.NewLambdaDestination(destinationFn, &LambdaDestinationOptions{ ResponseOnly: jsii.Boolean(true), }), })
func NewLambdaDestination ¶
func NewLambdaDestination(fn awslambda.IFunction, options *LambdaDestinationOptions) LambdaDestination
type LambdaDestinationOptions ¶
type LambdaDestinationOptions struct { // Whether the destination function receives only the `responsePayload` of the source function. // // When set to `true` and used as `onSuccess` destination, the destination // function will be invoked with the payload returned by the source function. // // When set to `true` and used as `onFailure` destination, the destination // function will be invoked with the error object returned by source function. // // See the README of this module to see a full explanation of this option. // Default: false The destination function receives the full invocation record. // ResponseOnly *bool `field:"optional" json:"responseOnly" yaml:"responseOnly"` }
Options for a Lambda destination.
Example:
// Auto-extract response payload with a lambda destination var destinationFn function sourceFn := lambda.NewFunction(this, jsii.String("Source"), &FunctionProps{ Runtime: lambda.Runtime_NODEJS_LATEST(), Handler: jsii.String("index.handler"), Code: lambda.Code_FromAsset(path.join(__dirname, jsii.String("lambda-handler"))), // auto-extract on success OnSuccess: destinations.NewLambdaDestination(destinationFn, &LambdaDestinationOptions{ ResponseOnly: jsii.Boolean(true), }), })
type S3Destination ¶ added in v2.168.0
type S3Destination interface { awslambda.IDestination // Returns a destination configuration. Bind(_scope constructs.Construct, fn awslambda.IFunction, _options *awslambda.DestinationOptions) *awslambda.DestinationConfig }
Use a S3 bucket as a Lambda destination.
Example:
// The code below shows an example of how to instantiate this type. // The values are placeholders you should change. import "github.com/aws/aws-cdk-go/awscdk" import "github.com/aws/aws-cdk-go/awscdk" var bucket bucket s3Destination := awscdk.Aws_lambda_destinations.NewS3Destination(bucket)
func NewS3Destination ¶ added in v2.168.0
func NewS3Destination(bucket awss3.IBucket) S3Destination
type SnsDestination ¶
type SnsDestination interface { awslambda.IDestination // Returns a destination configuration. Bind(_scope constructs.Construct, fn awslambda.IFunction, _options *awslambda.DestinationOptions) *awslambda.DestinationConfig }
Use a SNS topic as a Lambda destination.
Example:
// An sns topic for successful invocations of a lambda function import sns "github.com/aws/aws-cdk-go/awscdk" myTopic := sns.NewTopic(this, jsii.String("Topic")) myFn := lambda.NewFunction(this, jsii.String("Fn"), &FunctionProps{ Runtime: lambda.Runtime_NODEJS_LATEST(), Handler: jsii.String("index.handler"), Code: lambda.Code_FromAsset(path.join(__dirname, jsii.String("lambda-handler"))), // sns topic for successful invocations OnSuccess: destinations.NewSnsDestination(myTopic), })
func NewSnsDestination ¶
func NewSnsDestination(topic awssns.ITopic) SnsDestination
type SqsDestination ¶
type SqsDestination interface { awslambda.IDestination // Returns a destination configuration. Bind(_scope constructs.Construct, fn awslambda.IFunction, _options *awslambda.DestinationOptions) *awslambda.DestinationConfig }
Use a SQS queue as a Lambda destination.
Example:
// An sqs queue for unsuccessful invocations of a lambda function import sqs "github.com/aws/aws-cdk-go/awscdk" deadLetterQueue := sqs.NewQueue(this, jsii.String("DeadLetterQueue")) myFn := lambda.NewFunction(this, jsii.String("Fn"), &FunctionProps{ Runtime: lambda.Runtime_NODEJS_LATEST(), Handler: jsii.String("index.handler"), Code: lambda.Code_FromInline(jsii.String("// your code")), // sqs queue for unsuccessful invocations OnFailure: destinations.NewSqsDestination(deadLetterQueue), })
func NewSqsDestination ¶
func NewSqsDestination(queue awssqs.IQueue) SqsDestination