Python Cloudwatch发送给SNS的JSON负载中有什么？我如何读取这些数据？

当Cloudwatch中触发警报时，我尝试使用Lambda解析数据。我目前正在使用SNS触发lambda；但是，我想知道发送给该Lambda的是什么数据，以便正确解析它

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如何读取SNS传递到Lambda的JSON报警数据？

最简单、最准确的方法是打印（事件）并实际查看有效负载中的内容，官方AWS doco为SNS事件Amazon SNS示例事件提供了以下结构

此外，这个特定于CloudWatch的示例可能很有用

{
"Records": [
{
  "EventSource": "aws:sns",
  "EventVersion": "1.0",
  "EventSubscriptionArn": "arn:aws:sns:eu-west-1:000000000000:cloudwatch-alarms:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "Sns": {
    "Type": "Notification",
    "MessageId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "TopicArn": "arn:aws:sns:eu-west-1:000000000000:cloudwatch-alarms",
    "Subject": "ALARM: \"Example alarm name\" in EU - Ireland",
    "Message": "{\"AlarmName\":\"Example alarm name\",\"AlarmDescription\":\"Example alarm description.\",\"AWSAccountId\":\"000000000000\",\"NewStateValue\":\"ALARM\",\"NewStateReason\":\"Threshold Crossed: 1 datapoint (10.0) was greater than or equal to the threshold (1.0).\",\"StateChangeTime\":\"2017-01-12T16:30:42.236+0000\",\"Region\":\"EU - Ireland\",\"OldStateValue\":\"OK\",\"Trigger\":{\"MetricName\":\"DeliveryErrors\",\"Namespace\":\"ExampleNamespace\",\"Statistic\":\"SUM\",\"Unit\":null,\"Dimensions\":[],\"Period\":300,\"EvaluationPeriods\":1,\"ComparisonOperator\":\"GreaterThanOrEqualToThreshold\",\"Threshold\":1.0}}",
    "Timestamp": "2017-01-12T16:30:42.318Z",
    "SignatureVersion": "1",
    "Signature": "Cg==",
    "SigningCertUrl": "https://sns.eu-west-1.amazonaws.com/SimpleNotificationService-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.pem",
    "UnsubscribeUrl": "https://sns.eu-west-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:eu-west-1:000000000000:cloudwatch-alarms:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "MessageAttributes": {}
  }
}
]
}

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最简单的方法是使用电子邮件JSON协议为cloudwatch发送警报数据的SNS主题创建新订阅，然后输入您的电子邮件并创建订阅

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通过单击电子邮件中的验证链接确认订阅。当CloudWatch下次发送警报时，您将在电子邮件中获得JSON数据，然后您可以了解如何正确解析它。

CloudWatch发送给SNS的实际有效负载

{
  "AlarmName": "Example alarm name",
  "AlarmDescription": "Example alarm description.",
  "AWSAccountId": "000000000000",
  "NewStateValue": "ALARM",
  "NewStateReason": "Threshold Crossed: 1 datapoint (10.0) was greater than or equal to the threshold (1.0).",
  "StateChangeTime": "2017-01-12T16:30:42.236+0000",
  "Region": "EU - Ireland",
  "OldStateValue": "OK",
  "Trigger": {
    "MetricName": "DeliveryErrors",
    "Namespace": "ExampleNamespace",
    "Statistic": "SUM",
    "Unit": null,
    "Dimensions": [],
    "Period": 300,
    "EvaluationPeriods": 1,
    "ComparisonOperator": "GreaterThanOrEqualToThreshold",
    "Threshold": 1
  }
}

如果您想在Lambda中阅读此事件

import json

def lambda_handler(event, context):
    alert_message = json.loads(json.dumps(event))["Records"][0]["Sns"]["Message"]

    return {
        'statusCode': 200,
        'body': json.dumps(alert_message)
    }

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这是最明智的回答。非常感谢。

import json

def lambda_handler(event, context):
    alert_message = json.loads(json.dumps(event))["Records"][0]["Sns"]["Message"]

    return {
        'statusCode': 200,
        'body': json.dumps(alert_message)
    }