如何知道Lambda函数本身的事件来源 [英] How to know event souce of lambda function in itself

问题描述

我想知道该函数中lambda函数的事件源.

I want to know the event source of lambda function in the function.

我想做的是使用某些AWS服务中的一个lambda函数(CloudWatch，S3，Step函数等)，并根据服务更改其行为.

What I want to do is to use one lambda function from some AWS service(CloudWatch, S3, Step functions, etc...) and to change its behavior depending on the service.

上下文对象(函数的参数之一)具有有关lambda函数的信息，但不具有有关事件源的信息.

A context object (one of arguments of the function) has information about the lambda function but not about event source.

有办法知道吗?

推荐答案

如果您已将Kinesis或DynamoDB流标识为使用API​​的Lambda函数的事件源

If you have identified a Kinesis or DynamoDB stream as an event source for a Lambda function with the API

aws lambda create-event-source-mapping

，那么您可以通过

aws lambda list-event-source-mappings

如果不这样做，则可以使用以下函数进行最佳猜测:

If you don't, then you can make a best guess with a function like the following:

function getLambdaEventSource(event) {
    if (event.Records && event.Records[0].cf) return 'isCloudfront';

    if (event.configRuleId && event.configRuleName && event.configRuleArn) return 'isAwsConfig';

    if (event.Records && (event.Records[0].eventSource === 'aws:codecommit')) return 'isCodeCommit';

    if (event.authorizationToken === "incoming-client-token") return 'isApiGatewayAuthorizer';

    if (event.StackId && event.RequestType && event.ResourceType) return 'isCloudFormation';

    if (event.Records && (event.Records[0].eventSource === 'aws:ses')) return 'isSes';

    if (event.pathParameters && event.pathParameters.proxy) return 'isApiGatewayAwsProxy';

    if (event.source === 'aws.events') return 'isScheduledEvent';

    if (event.awslogs && event.awslogs.data) return 'isCloudWatchLogs';

    if (event.Records && (event.Records[0].EventSource === 'aws:sns')) return 'isSns';

    if (event.Records && (event.Records[0].eventSource === 'aws:dynamodb')) return 'isDynamoDb';

    if (event.records && event.records[0].approximateArrivalTimestamp) return 'isKinesisFirehose';

    if (event.records && event.deliveryStreamArn && event.deliveryStreamArn.startsWith('arn:aws:kinesis:')) return 'isKinesisFirehose';

    if (event.eventType === 'SyncTrigger' && event.identityId && event.identityPoolId) return 'isCognitoSyncTrigger';

    if (event.Records && event.Records[0].eventSource === 'aws:kinesis') return 'isKinesis';

    if (event.Records && event.Records[0].eventSource === 'aws:s3') return 'isS3';

    if (event.operation && event.message) return 'isMobileBackend';

}

我说这是最佳猜测，因为诸如API网关请求之类的事件源可能正在发送任何内容.如果您确定不会遇到这种情况，则上面的功能可以解决问题.

I say that it's a best guess because an event source like an API gateway request can potentially be sending anything. If you're sure that you won't have such a case, then the function above can do the trick.

这篇关于如何知道Lambda函数本身的事件来源的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！