AWS Lambda python 获取 cloudwatch 警报信息以触发 MS 团队的警报答案

【问题标题】：AWS Lambda python to get cloudwatch alarm info to trigger an alert to MS teamsAWS Lambda python 获取 cloudwatch 警报信息以触发 MS 团队的警报
【发布时间】：2020-08-30 07:46:15
【问题描述】：

我设置了几个云手表警报，当警报响起时，它会触发 lambda 函数。在 lambda 中，我试图读取 json 并将其通知给 MS 团队。但我无法从基于 json 的警报名称中获取。

下面是json

{
  'Records': [
    {
      'EventSource': 'aws:sns',
      'EventVersion': '1.0',
      'EventSubscriptionArn': 'arn:aws:sns:ap-southeast-1:123:-teams-lambda-trigger:123-971d-4f70-927e-123',
      'Sns': {
        'Type': 'Notification',
        'MessageId': '12-d0b8-5a86-8b33-123',
        'TopicArn': 'arn:aws:sns:ap-southeast-1:123:vip-prestogo-teams-lambda-trigger',
        'Subject': 'ALARM: "AuthenticationFailedException-was101" in Asia Pacific (Singapore)',
        'Message': '{"AlarmName":"AuthenticationFailedException-was101","AlarmDescription":"Found \\"AuthenticationFailedException\\" in 123","AWSAccountId":"123","NewStateValue":"ALARM","NewStateReason":"Threshold Crossed: 1 out of the last 1 datapoints [1.0 (30/08/20 07:38:00)] was greater than or equal to the threshold (-1.0) (minimum 1 datapoint for OK -> ALARM transition).","StateChangeTime":"2020-08-30T07:39:22.330+0000","Region":"Asia Pacific (Singapore)","AlarmArn":"arn:aws:cloudwatch:ap-southeast-1:123:alarm:AuthenticationFailedException-was101","OldStateValue":"OK","Trigger":{"MetricName":"AuthenticationFailedException-was101","Namespace":"AuthenticationFailedException-was101","StatisticType":"Statistic","Statistic":"AVERAGE","Unit":null,"Dimensions":[],"Period":60,"EvaluationPeriods":1,"ComparisonOperator":"GreaterThanOrEqualToThreshold","Threshold":-1.0,"TreatMissingData":"- TreatMissingData:                    notBreaching","EvaluateLowSampleCountPercentile":""}}',
        'Timestamp': '2020-08-30T07:39:22.372Z',
        'SignatureVersion': '1',
        'Signature': '123/WJa6/3saRvSsz+eDW10LZaAlR7jMhnU4jE73UM/+123/123/123/123/123+j+pjE0nldGG+123/xouonYXLkBrfRQPtr1sv/RzrIJ/kTYr3EwSkGL032HNrOeWmdGZ9D4gIJ4ir/mbnbSZV7w==',
        'SigningCertUrl': 'https://sns.ap-southeast-1.amazonaws.com/SimpleNotificationService.pem',
        'UnsubscribeUrl': 'https://sns.ap-southeast-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:ap-southeast-1:123:-teams-lambda-trigger:46235663-971d-4f70-927e-0a420040a154',
        'MessageAttributes': {
          
        }
      }
    }
  ]
}

尝试如下但失败：

 message = event['Records'][0]['Sns']['Message']
alarm =message['AlarmName']

我收到如下错误：

字符串索引必须是整数：TypeError 回溯（最近一次通话最后）：文件“/var/task/lambda_function.py”，第 15 行，在 lambda_handler “文本”：事件['Records'][0]['Sns']['Message']['AlarmDescription'] TypeError: 字符串索引必须是整数

请帮忙

【问题讨论】：

标签： python json amazon-web-services aws-lambda

【解决方案1】：

这是“AlarmName”属性位于 json 字符串中的结果。您需要先对其进行解析，以便可以访问该属性。

使用json.parse 函数检索警报名称，如下面的示例 Lambda 函数。

import boto3
import json


def lambda_handler(event, context):
    message = event['Records'][0]['Sns']['Message']
    message = json.loads(message)
    alarm_name = message["AlarmName"]
    print(alarm_name)

我在 Lambda 中使用以下事件对此进行了测试

{
  "Records": [
    {
      "EventSource": "aws:sns",
      "EventVersion": "1.0",
      "EventSubscriptionArn": "arn:aws:sns:ap-southeast-1:123:-teams-lambda-trigger:123-971d-4f70-927e-123",
      "Sns": {
        "Type": "Notification",
        "MessageId": "12-d0b8-5a86-8b33-123",
        "TopicArn": "arn:aws:sns:ap-southeast-1:123:vip-prestogo-teams-lambda-trigger",
        "Subject": "ALARM: \"AuthenticationFailedException-was101\" in Asia Pacific (Singapore)",
        "Message": "{\"AlarmName\":\"AuthenticationFailedException-was101\",\"AlarmDescription\":\"Found \\\"AuthenticationFailedException\\\" in 123\",\"AWSAccountId\":\"123\",\"NewStateValue\":\"ALARM\",\"NewStateReason\":\"Threshold Crossed: 1 out of the last 1 datapoints [1.0 (30/08/20 07:38:00)] was greater than or equal to the threshold (-1.0) (minimum 1 datapoint for OK -> ALARM transition).\",\"StateChangeTime\":\"2020-08-30T07:39:22.330+0000\",\"Region\":\"Asia Pacific (Singapore)\",\"AlarmArn\":\"arn:aws:cloudwatch:ap-southeast-1:123:alarm:AuthenticationFailedException-was101\",\"OldStateValue\":\"OK\",\"Trigger\":{\"MetricName\":\"AuthenticationFailedException-was101\",\"Namespace\":\"AuthenticationFailedException-was101\",\"StatisticType\":\"Statistic\",\"Statistic\":\"AVERAGE\",\"Unit\":null,\"Dimensions\":[],\"Period\":60,\"EvaluationPeriods\":1,\"ComparisonOperator\":\"GreaterThanOrEqualToThreshold\",\"Threshold\":-1.0,\"TreatMissingData\":\"- TreatMissingData:                    notBreaching\",\"EvaluateLowSampleCountPercentile\":\"\"}}",
        "Timestamp": "2020-08-30T07:39:22.372Z",
        "SignatureVersion": "1",
        "Signature": "123/WJa6/3saRvSsz+eDW10LZaAlR7jMhnU4jE73UM/+123/123/123/123/123+j+pjE0nldGG+123/xouonYXLkBrfRQPtr1sv/RzrIJ/kTYr3EwSkGL032HNrOeWmdGZ9D4gIJ4ir/mbnbSZV7w==",
        "SigningCertUrl": "https://sns.ap-southeast-1.amazonaws.com/SimpleNotificationService.pem",
        "UnsubscribeUrl": "https://sns.ap-southeast-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:ap-southeast-1:123:-teams-lambda-trigger:46235663-971d-4f70-927e-0a420040a154",
        "MessageAttributes": {
          
        }
      }
    }
  ]
}

这个 Lambda 函数输出字符串AuthenticationFailedException-was101

【讨论】：

【解决方案2】：

您的event['Records'][0]['Sns']['Message'] 是json 字符串，而不是python 字典。您必须使用 json.loads 将其解析到字典中：

import json # if not already present

message = json.loads(event['Records'][0]['Sns']['Message'])

alarm_name = message['AlarmName']

【讨论】：

【解决方案3】：

message = event['Records'][0]['Sns']['Message']，您的消息是一个字符串，您需要将其转换为字典。每当你有这样的疑问时，你可以使用 print(type(variable_name))。您的 message 值可能有也可能没有那个特定的键，因此您可以使用 get() 函数来检索该值。

import json 
message = json.loads(event['Records'][0]['Sns']['Message'])
alarm_name = message.get('AlarmName', None)
if alarm_name not None:
   {your action}
else:
    {some default action when key not present}

【讨论】：