Taxonomy of event- driven Lambda messages? - amazon-web-services

Question

I'm building event driven AWS stacks with Lambda+APIGateway+SQS+SNS+S3+DynamoDB.
One of my constant frustrations is that, if you bind any of the above to Lambda (either through event notifications or event source mappings), the formats of the event messages received by the Lambda are completely different - so a message sent by S3 is completely different to one sent by SQS which is completely different to one sent by DynamoDB etc.
Normally I have to set up a Cloudformation stack with an event source + event source mapping + Lambda, then push a message onto the event source to see what message actually results. What a giant pain.
Is there not a single combined resource out there which lists the different schema formats of different event messages ? Hoping someone can point me in the right direction.

Answer 1

Lambda console provides some example events in Configure test event. Here are the examples from the console for the services you mentioned.
APIGateway (aws proxy)
{
"body": "eyJ0ZXN0IjoiYm9keSJ9",
"resource": "/{proxy+}",
"path": "/path/to/resource",
"httpMethod": "POST",
"isBase64Encoded": true,
"queryStringParameters": {
"foo": "bar"
},
"multiValueQueryStringParameters": {
"foo": [
"bar"
]
},
"pathParameters": {
"proxy": "/path/to/resource"
},
"stageVariables": {
"baz": "qux"
},
"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-east-1.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"
},
"multiValueHeaders": {
"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": [
"0123456789.execute-api.us-east-1.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"
]
},
"requestContext": {
"accountId": "123456789012",
"resourceId": "123456",
"stage": "prod",
"requestId": "c6af9ac6-7b61-11e6-9a41-93e8deadbeef",
"requestTime": "09/Apr/2015:12:34:56 +0000",
"requestTimeEpoch": 1428582896000,
"identity": {
"cognitoIdentityPoolId": null,
"accountId": null,
"cognitoIdentityId": null,
"caller": null,
"accessKey": null,
"sourceIp": "127.0.0.1",
"cognitoAuthenticationType": null,
"cognitoAuthenticationProvider": null,
"userArn": null,
"userAgent": "Custom User Agent String",
"user": null
},
"path": "/prod/path/to/resource",
"resourcePath": "/{proxy+}",
"httpMethod": "POST",
"apiId": "1234567890",
"protocol": "HTTP/1.1"
}
}
SQS
{
"Records": [
{
"messageId": "19dd0b57-b21e-4ac1-bd88-01bbb068cb78",
"receiptHandle": "MessageReceiptHandle",
"body": "Hello from SQS!",
"attributes": {
"ApproximateReceiveCount": "1",
"SentTimestamp": "1523232000000",
"SenderId": "123456789012",
"ApproximateFirstReceiveTimestamp": "1523232000001"
},
"messageAttributes": {},
"md5OfBody": "7b270e59b47ff90a553787216d55d91d",
"eventSource": "aws:sqs",
"eventSourceARN": "arn:aws:sqs:us-east-1:123456789012:MyQueue",
"awsRegion": "us-east-1"
}
]
}
SNS
{
"Records": [
{
"EventSource": "aws:sns",
"EventVersion": "1.0",
"EventSubscriptionArn": "arn:aws:sns:us-east-1:{{{accountId}}}:ExampleTopic",
"Sns": {
"Type": "Notification",
"MessageId": "95df01b4-ee98-5cb9-9903-4c221d41eb5e",
"TopicArn": "arn:aws:sns:us-east-1:123456789012:ExampleTopic",
"Subject": "example subject",
"Message": "example message",
"Timestamp": "1970-01-01T00:00:00.000Z",
"SignatureVersion": "1",
"Signature": "EXAMPLE",
"SigningCertUrl": "EXAMPLE",
"UnsubscribeUrl": "EXAMPLE",
"MessageAttributes": {
"Test": {
"Type": "String",
"Value": "TestString"
},
"TestBinary": {
"Type": "Binary",
"Value": "TestBinary"
}
}
}
}
]
}
S3 (put)
{
"Records": [
{
"eventVersion": "2.0",
"eventSource": "aws:s3",
"awsRegion": "us-east-1",
"eventTime": "1970-01-01T00:00:00.000Z",
"eventName": "ObjectCreated:Put",
"userIdentity": {
"principalId": "EXAMPLE"
},
"requestParameters": {
"sourceIPAddress": "127.0.0.1"
},
"responseElements": {
"x-amz-request-id": "EXAMPLE123456789",
"x-amz-id-2": "EXAMPLE123/5678abcdefghijklambdaisawesome/mnopqrstuvwxyzABCDEFGH"
},
"s3": {
"s3SchemaVersion": "1.0",
"configurationId": "testConfigRule",
"bucket": {
"name": "example-bucket",
"ownerIdentity": {
"principalId": "EXAMPLE"
},
"arn": "arn:aws:s3:::example-bucket"
},
"object": {
"key": "test/key",
"size": 1024,
"eTag": "0123456789abcdef0123456789abcdef",
"sequencer": "0A1B2C3D4E5F678901"
}
}
}
]
}
DynamoDB
{
"Records": [
{
"eventID": "c4ca4238a0b923820dcc509a6f75849b",
"eventName": "INSERT",
"eventVersion": "1.1",
"eventSource": "aws:dynamodb",
"awsRegion": "us-east-1",
"dynamodb": {
"Keys": {
"Id": {
"N": "101"
}
},
"NewImage": {
"Message": {
"S": "New item!"
},
"Id": {
"N": "101"
}
},
"ApproximateCreationDateTime": 1428537600,
"SequenceNumber": "4421584500000000017450439091",
"SizeBytes": 26,
"StreamViewType": "NEW_AND_OLD_IMAGES"
},
"eventSourceARN": "arn:aws:dynamodb:us-east-1:123456789012:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899"
},
{
"eventID": "c81e728d9d4c2f636f067f89cc14862c",
"eventName": "MODIFY",
"eventVersion": "1.1",
"eventSource": "aws:dynamodb",
"awsRegion": "us-east-1",
"dynamodb": {
"Keys": {
"Id": {
"N": "101"
}
},
"NewImage": {
"Message": {
"S": "This item has changed"
},
"Id": {
"N": "101"
}
},
"OldImage": {
"Message": {
"S": "New item!"
},
"Id": {
"N": "101"
}
},
"ApproximateCreationDateTime": 1428537600,
"SequenceNumber": "4421584500000000017450439092",
"SizeBytes": 59,
"StreamViewType": "NEW_AND_OLD_IMAGES"
},
"eventSourceARN": "arn:aws:dynamodb:us-east-1:123456789012:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899"
},
{
"eventID": "eccbc87e4b5ce2fe28308fd9f2a7baf3",
"eventName": "REMOVE",
"eventVersion": "1.1",
"eventSource": "aws:dynamodb",
"awsRegion": "us-east-1",
"dynamodb": {
"Keys": {
"Id": {
"N": "101"
}
},
"OldImage": {
"Message": {
"S": "This item has changed"
},
"Id": {
"N": "101"
}
},
"ApproximateCreationDateTime": 1428537600,
"SequenceNumber": "4421584500000000017450439093",
"SizeBytes": 38,
"StreamViewType": "NEW_AND_OLD_IMAGES"
},
"eventSourceARN": "arn:aws:dynamodb:us-east-1:123456789012:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899"
}
]
}