我可以在 IoT 規則 SQL 中動態設置條件嗎？

Question

在 yaml 文件的這一部分，我需要更新 sql 語句中的條件。

例如，用戶可以將條件重置為等於 20 而不是 30。

NotifyTemperatureAlarm:
Type: 'AWS::Serverless::Function'
DependsOn: AlertSNSTopic
Properties:
  CodeUri: src/notify_temperature_alarm/
  Handler: app.lambda_handler
  Runtime: python3.9
  Architectures:
    - x86_64
  Events:
    PutImageEvent:
      Type: IoTRule
      Properties:
        Sql: Select * FROM 'device/temperature/alarms' where value > 30
  Policies:
    Version: "2012-10-17"
    Statement:
      - Effect: Allow
        Action: "sns:*"
        Resource: "*"
  Environment:
    Variables:
      alert_sns: !Ref AlertSNSTopic

Answer 1

在參數部分設置您的條件，例如

Parameters:
TemperatureThreshold:
  Type: Number
  Default: '20'

然后更新 NotifyTemperatureAlarm 例如

NotifyTemperatureAlarm:
Type: 'AWS::Serverless::Function'
DependsOn: AlertSNSTopic
Properties:
  CodeUri: src/notify_temperature_alarm/
  Handler: app.lambda_handler
  Runtime: python3.9
  Architectures:
    - x86_64
  Events:
    PutImageEvent:
      Type: IoTRule
      Properties:
        Sql: !Sub "SELECT * FROM 'device/temperature/alarms' where value > ${TemperatureThreshold}"
  Policies:
    Version: "2012-10-17"
    Statement:
      - Effect: Allow
        Action: "sns:*"
        Resource: "*"
  Environment:
    Variables:
      alert_sns: !Ref AlertSNSTopic

要使 TemperatureThreshold 可調，您可以從 cloudformation 更新它，例如

client = boto3.client('cloudformation')  

response = client.update_stack(
    StackName = "your_stack_name",
    UsePreviousTemplate = True,
    Capabilities = ['CAPABILITY_IAM'],
    Parameters=[
        {
            'ParameterKey': 'TemperatureThreshold',
            'ParameterValue': str(new_threshold),
        }
    ]
)