AWS Lambda Trigger

The Lambda trigger provides your Flogo application the ability to start actions running as an AWS Lambda function.

How it works

In Lambda, functions can be triggered by a variety of event sources (like Amazon S3, or the Amazon API Gateway) and in Lambda terms, each of them would need a specific method to serve as starting point. To overcome that, and make it possible to create just one action that can be triggered by multiple events, the Lambda trigger abstracts the incoming event, making sure that no change is needed when you want to hook up other events to the same trigger. If needed you can also specify the event type to route specific events to specific actions.

Installation

Flogo CLI

flogo install github.com/project-flogo/aws-contrib/trigger/lambda

Configuration

Handler Settings:

Name	Type	Description
eventType	string	The type of event to handle, (e.g. aws:s3, aws:sns)

Output:

Name	Type	Description
context	object	The lambda context information
event	object	The event data
eventType	string	The event type, (e.g. aws:s3, aws:sns)

Reply:

Name	Type	Description
status	int	The status code to reply with
data	any	The data to reply with

Event Types

ID	Service
aws:apigw	AWS API Gateway
aws:autoscaling	AWS AutoScaling
aws:cloudfront	AWS CloudFront
aws:cloudwatch	AWS CloudWatch
aws:cloudwatch-logs	AWS CloudWatch Logs
aws:codecommit	AWS CodeCommit
aws:codepipeline	AWS CodePipeline
aws:cognito	AWS Cognito
aws:config	AWS Config
aws:dynamodb	AWS Dynamodb
aws:kinesis	AWS Kinesis
aws:kinesis-analytics	AWS Kinesis Analytics
aws:kinesis-firehose	AWS Kinesis Firehose
aws:s3	AWS S3
aws:ses	AWS SES
aws:sns	AWS SNS
aws:sqs	AWS SQS

Context

The context object contains details about the Flogo app and the runtime

{
    "awsRequestId":"6301513f-c5c5-11e8-9997-c9e96bfbdd33",
    "functionName":"TestApp",
    "functionVersion":"$LATEST",
    "logGroupName":"/aws/lambda/TestApp",
    "logStreamName":"2018/10/01/[$LATEST]ec9b2c81da4b4307ab50738bb1eeb28f",
    "memoryLimitInMB":128
}

Name	Description
awsRequestId	The request ID that AWS associated with the Lambda execution
functionName	The name of the function that is executed
functionVersion	The version of the function that is executed
logGroupName	The name of the log group in AWS CloudWatch where logs are sent to
logStreamName	The logstream to which events are sent
memoryLimitInMB	The amount of RAM your function has available

Example events

The events themselves are not changed by the Lambda trigger, though without changing your Lambda code a single app can handle multiple types of events. Each of the properties of the event are accessible using the dot notation in the mappings.

Amazon S3

When Amazon S3 emits a "PUT" event, the event details that are passed to the action will look like

{
    "Records": [
        {
            "awsRegion": "us-west-2",
            "eventName": "ObjectCreated:Put",
            "eventSource": "aws:s3",
            "eventTime": "1970-01-01T00:00:00.000Z",
            "eventVersion": "2.0",
            "requestParameters": {
                "sourceIPAddress": "127.0.0.1"
            },
            "responseElements": {
                "x-amz-id-2": "EXAMPLE123/5678abcdefghijklambdaisawesome/mnopqrstuvwxyzABCDEFGH",
                "x-amz-request-id": "EXAMPLE123456789"
            },
            "s3": {
                "bucket": {
                    "arn": "arn:aws:s3:::example-bucket",
                    "name": "example-bucket",
                    "ownerIdentity": {
                        "principalId": "EXAMPLE"
                    }
                },
                "configurationId": "testConfigRule",
                "object": {
                    "eTag": "0123456789abcdef0123456789abcdef",
                    "key": "test/key",
                    "sequencer": "0A1B2C3D4E5F678901",
                    "size": 1024
                },
                "s3SchemaVersion": "1.0"
            },
            "userIdentity": {
                "principalId": "EXAMPLE"
            }
        }
    ]
}

Amazon DynamoDB

When Amazon DynamoDB emits an "Update" event, the event details that are passed to the action will look like

{
    "Records": [
        {
            "awsRegion": "us-west-2",
            "dynamodb": {
                "Keys": {
                    "Id": {
                        "N": "101"
                    }
                },
                "NewImage": {
                    "Id": {
                        "N": "101"
                    },
                    "Message": {
                        "S": "New item!"
                    }
                },
                "SequenceNumber": "111",
                "SizeBytes": 26,
                "StreamViewType": "NEW_AND_OLD_IMAGES"
            },
            "eventID": "1",
            "eventName": "INSERT",
            "eventSource": "aws:dynamodb",
            "eventSourceARN": "arn:aws:dynamodb:us-west-2:account-id:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899",
            "eventVersion": "1.0"
        }
    ]
}

AWS CloudWatch

When AWS CloudWatch emits a scheduled event, the event details that are passed to the action will look like

{
    "account": "123456789012",
    "detail": {},
    "detail-type": "Scheduled Event",
    "id": "cdc73f9d-aea9-11e3-9d5a-835b769c0d9c",
    "region": "us-east-1",
    "resources": [
        "arn:aws:events:us-east-1:123456789012:rule/my-schedule"
    ],
    "source": "aws.events",
    "time": "1970-01-01T00:00:00Z"
}

Amazon API Gateway

When Amazon API Gateway forwards an API call, the event details that are passed to the action will look like

{
    "body": "eyJ0ZXN0IjoiYm9keSJ9",
    "headers": {
        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
        "Accept-Encoding": "gzip, deflate, sdch",
        "Accept-Language": "en-US,en;q=0.8",
        "Cache-Control": "max-age=0",
        "CloudFront-Forwarded-Proto": "https",
        "CloudFront-Is-Desktop-Viewer": "true",
        "CloudFront-Is-Mobile-Viewer": "false",
        "CloudFront-Is-SmartTV-Viewer": "false",
        "CloudFront-Is-Tablet-Viewer": "false",
        "CloudFront-Viewer-Country": "US",
        "Host": "1234567890.execute-api.us-west-2.amazonaws.com",
        "Upgrade-Insecure-Requests": "1",
        "User-Agent": "Custom User Agent String",
        "Via": "1.1 08f323deadbeefa7af34d5feb414ce27.cloudfront.net (CloudFront)",
        "X-Amz-Cf-Id": "cDehVQoZnx43VYQb9j2-nvCh-9z396Uhbp027Y2JvkCPNLmGJHqlaA==",
        "X-Forwarded-For": "127.0.0.1, 127.0.0.2",
        "X-Forwarded-Port": "443",
        "X-Forwarded-Proto": "https"
    },
    "httpMethod": "POST",
    "isBase64Encoded": "false",
    "path": "/path/to/resource",
    "pathParameters": {
        "proxy": "/path/to/resource"
    },
    "queryStringParameters": {
        "foo": "bar"
    },
    "requestContext": {
        "accountId": "123456789012",
        "apiId": "1234567890",
        "httpMethod": "POST",
        "identity": {
            "accessKey": null,
            "accountId": null,
            "caller": null,
            "cognitoAuthenticationProvider": null,
            "cognitoAuthenticationType": null,
            "cognitoIdentityId": null,
            "cognitoIdentityPoolId": null,
            "sourceIp": "127.0.0.1",
            "user": null,
            "userAgent": "Custom User Agent String",
            "userArn": null
        },
        "path": "/prod/path/to/resource",
        "protocol": "HTTP/1.1",
        "requestId": "c6af9ac6-7b61-11e6-9a41-93e8deadbeef",
        "requestTime": "09/Apr/2015:12:34:56 +0000",
        "requestTimeEpoch": 1428582896000,
        "resourceId": "123456",
        "resourcePath": "/{proxy+}",
        "stage": "prod"
    },
    "resource": "/{proxy+}",
    "stageVariables": {
        "baz": "qux"
    }
}