Terraform配置EventBridge调度RDS Data Execute Statement的负载格式问题

问题场景 #

尝试通过Terraform配置AWS EventBridge Scheduler，以通用目标调用RDS Data Execute Statement API，实现每日自动执行SQL脚本的定时任务。初始简化脚本如下：

resource "aws_scheduler_schedule" "some_sql_script" {
  name = "..."
  description = "..."
  schedule_expression = "cron(30 0 * * ? *)"
  schedule_expression_timezone = "Europe/Berlin"
  state = "ENABLED"
  flexible_time_window {
    mode = "OFF"
  }
  target {
    arn = "arn:aws:scheduler:::aws-sdk:rdsdata:executeStatement"
    role_arn =  ...
    input = jsonencode({
        "resourceArn": "...",
        "secretArn": "...",
        "sql": "..."
  })
  }
}

执行terraform apply时触发错误：

creating Amazon EventBridge Scheduler Schedule (...): operation error Scheduler: CreateSchedule, https response error StatusCode: 400, RequestID: ..., ValidationException: Invalid RequestJson provided. Reason Request payload is missing the following field(s): ResourceArn, SecretArn, Sql.

去掉jsonencode直接传入对象配置时，又出现新错误：

Inappropriate value for attribute "input": string required.

解决方法 #

问题核心在于AWS EventBridge Scheduler调用AWS SDK目标时，要求请求参数的键名采用首字母大写的驼峰格式（而非Terraform常用的小驼峰）。修正后的配置需要保留jsonencode（因为input字段强制要求字符串类型），同时调整参数键名的大小写：

resource "aws_scheduler_schedule" "some_sql_script" {
  name = "..."
  description = "..."
  schedule_expression = "cron(30 0 * * ? *)"
  schedule_expression_timezone = "Europe/Berlin"
  state = "ENABLED"
  flexible_time_window {
    mode = "OFF"
  }
  target {
    arn = "arn:aws:scheduler:::aws-sdk:rdsdata:executeStatement"
    role_arn =  ...
    input = jsonencode({
        "ResourceArn": "...", # 首字母大写匹配API要求
        "SecretArn": "...",   # 首字母大写匹配API要求
        "Sql": "..."          # 首字母大写匹配API要求
    })
  }
}

关键说明 #

• input字段必须是JSON字符串，因此必须用jsonencode将Terraform对象转换为字符串格式，否则会触发"string required"错误。
• AWS SDK的executeStatement接口要求参数名首字母大写，和Terraform常规的小驼峰命名规则不同，这是导致字段缺失错误的根本原因。

内容的提问来源于stack exchange，提问作者Leonard Buhl