尝试读取AWS SNS消息时出错 [英] Error when trying to read AWS SNS message

问题描述

我需要将Rekognition发送的消息返回给SNS，但是我在CloudWatch中收到此错误：

I need to return the message sent by Rekognition to SNS but I get this error in CloudWatch:

'Records'：KeyError Traceback （最近一次通话最近一次）：文件
/var/task/AnalyzeVideo/lambda_function.py，第34行，在
中lambda_handler message = event [ Records] [0] [ Sns] [消息]
KeyError：'记录'

'Records': KeyError Traceback (most recent call last): File "/var/task/AnalyzeVideo/lambda_function.py", line 34, in lambda_handler message = event["Records"][0]["Sns"]["Message"] KeyError: 'Records'

代码：

def detect_labels(bucket, key):
    response = rekognition.start_label_detection(
        Video = {
            "S3Object": {
                "Bucket": BUCKET,
                "Name": KEY
            }
        },
        NotificationChannel = {
            "SNSTopicArn": TOPIC_ARN,
            "RoleArn": ROLE_ARN
        }
    )

    return response

def lambda_handler(event, context):
    reko_response = detect_labels(BUCKET, KEY)
    message = event["Records"][0]["Sns"]["Message"]
    return message

这是在AWS中实现Rekognition存储视频的正确方法吗带有python的Lambda我没有找到任何示例。

And is this the correct way of implementing Rekognition stored video in AWS Lambda with python I didn't find any examples on it.

更新：

我的应用所需的步骤

1. 在前端，用户使用API​​网关触发lambda函数，其中
   将文件发送到s3


2. 文件到达时触发相同的lambda函数，以应用视频
   识别并将jobId发送到SNS


3. 当SNS收到消息时，触发相同的lambda函数来获取
   标签数据并将数据通过API网关返回给用户

推荐答案

您的函数正在调用 rekognition。）（大概您已经创建了 rekognition 客户端

Your function is calling rekognition.start_label_detection() (and presumably you have created the rekognition client in code not shown).

此API调用开始对视频进行标签检测。完成后，它将向指定的SNS主题发布消息。您可以将Lambda函数连接到SNS，以在完成时检索标签检测的详细信息。

This API call starts label detection on a video. When it is finished, it will publish a message to the given SNS topic. You can connect a Lambda function to SNS to retrieve the details of the label detection when it is finished.

但是，您的代码混淆了操作的顺序。相反，您应该执行以下操作：

However, your code is getting the order of operations mixed up. Instead, you should be doing the following:

• 某些事情（可能不是Lambda函数）应调用 start_label_detection（） 开始扫描视频。这可能需要几分钟。


• 应该配置Lambda函数以在SNS主题收到消息时触发。


• 然后传递Lambda函数邮件的副本，可用于调用 get_label_detection（）来检索扫描的详细信息。

• Something (probably not a Lambda function) should call start_label_detection() to begin the process of scanning the video. This can take several minutes.
• A Lambda function should be configured to trigger when the SNS topic receives a message.
• The Lambda function is then passed a copy of the message, which can be used to call get_label_detection() to retrieve the details of the scan.

因此，第一步是将初始 start_label_detection（）请求与检索结果的代码分开。然后，修改Lambda函数以通过 get_label_detection（）检索结果并处理结果。

So, your first step is to separate the initial start_label_detection() request from the code that retrieves the results. Then, modify the Lambda function to retrieve the results via get_label_detection() and process the results.

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