Cloudwatch 发送到 SNS 的 JSON 负载中有什么？我怎样才能读取这些数据？

Question

我正在尝试在 Cloudwatch 中触发警报时使用 Lambda 解析数据。我目前正在使用 SNS 来触发 lambda；但是，我想知道哪些数据被发送到 Lambda，以便我可以正确解析它。

如何读取通过 SNS 传递到 Lambda 的 JSON 警报数据？

Answer 1

最简单和最准确的方法是print(event)并实际查看有效负载中的内容，官方AWS doco为SNS事件提供了以下结构Amazon SNS Sample Event, reference

{
"Records": [
{
  "EventVersion": "1.0",
  "EventSubscriptionArn": eventsubscriptionarn,
  "EventSource": "aws:sns",
  "Sns": {
    "SignatureVersion": "1",
    "Timestamp": "1970-01-01T00:00:00.000Z",
    "Signature": "EXAMPLE",
    "SigningCertUrl": "EXAMPLE",
    "MessageId": "95df01b4-ee98-5cb9-9903-4c221d41eb5e",
    "Message": "Hello from SNS!",
    "MessageAttributes": {
      "Test": {
        "Type": "String",
        "Value": "TestString"
      },
      "TestBinary": {
        "Type": "Binary",
        "Value": "TestBinary"
      }
    },
    "Type": "Notification",
    "UnsubscribeUrl": "EXAMPLE",
    "TopicArn": topicarn,
    "Subject": "TestInvoke"
  }
}
]
}

此外，这个 CloudWatch 特定示例可能很有用

{
"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": {}
  }
}
]
}

Answer 2

最简单的方法是使用Email-JSON协议为cloudwatch发送报警数据的SNS Topic创建一个新的订阅，然后输入您的电子邮件并创建订阅。

点击电子邮件中的验证 link 确认订阅。当 CloudWatch 下次发送警报时，您将在电子邮件中收到 JSON 数据，然后您可以找出如何正确解析它。

Answer 3

Cloudwatch 发送到 SNS 的实际负载，

{
  "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)
    }

Cloudwatch 发送到 SNS 的 JSON 负载中有什么？我怎样才能读取这些数据？

What is in the JSON payload Cloudwatch sends to SNS? How can I read that data?

python

amazon-web-services

amazon-sns

amazon-cloudwatch

aws-lambda