“for_each”值取决于无法确定的资源属性（Terraform）

我有一个 terraform 配置，需要：

1. 创建一个 lambda
2. 调用 lambda
3. 迭代 lambda 的 json 结果，返回一个数组并为数组中的每个条目创建一个 CloudWatch 事件规则

相关代码如下：

Create lambda code...

data "aws_lambda_invocation" "run_lambda" {
  function_name = "${aws_lambda_function.deployed_lambda.function_name}"

  input = <<JSON
  {}
  JSON
  depends_on = [aws_lambda_function.deployed_lambda]
}

resource "aws_cloudwatch_event_rule" "aws_my_cloudwatch_rule" {
  for_each = {for record in jsondecode(data.aws_lambda_invocation.run_lambda.result).entities : record.entityName => record} 
    name = "${each.value.entityName}-event"
    description = "Cloudwatch rule for ${each.value.entityName}"
    schedule_expression = "cron(${each.value.cronExpression})"
}

问题是当我运行它时，我得到：

Error: Invalid for_each argument

  on lambda.tf line 131, in resource "aws_cloudwatch_event_rule" "aws_my_cloudwatch_rule":
 131:   for_each = {for record in jsondecode(data.aws_lambda_invocation.aws_lambda_invocation.result).entities : record.entityName => record}

The "for_each" value depends on resource attributes that cannot be determined
until apply, so Terraform cannot predict how many instances will be created.
To work around this, use the -target argument to first apply only the
resources that the for_each depends on.

我已经阅读了很多有关该问题的帖子，但找不到解决方法。
问题在于，Terraform 需要在创建 lambda 之前的规划阶段知道 lambda 返回的数组的大小。
解决此类任务的最佳方法是什么？
由于它作为 CI/CD 管道的一部分运行，我更喜欢不包含“-target”标志的解决方案。

一种可能性是重新考虑for_each并使用count相反，如果合适的话。for_each有一些主要的限制。我遇到了类似的事情（对我来说似乎是一个主要错误，但他们说这是一个功能） 假设我正在部署三个虚拟机，并希望将它们绑定到负载均衡器：

resource "aws_instance" "xxx-IIS-004" {

  ami               = var.ami["Windows Server 2019"]
  instance_type     = var.depoy_lowcost ? var.default_instance_type : "m5.2xlarge"
  count             = "3"
  ...

当我尝试使用时for_each, I get “for_each”值取决于无法确定的资源属性...或元组错误。

Fails:

resource "aws_elb_attachment" "attachments_004" {
  depends_on = [ aws_instance.xxx-IIS-004 ]
  elb        = data.aws_elb.loadBalancer.id
  for_each   = aws_instance.xxx-IIS-004[*]
  instance   = each.value.id
}

Works*

locals {
  att_004 = join("_", aws_instance.xxx-IIS-004[*].id )
}

resource "aws_elb_attachment" "attachments_004" {
  depends_on = [ aws_instance.xxx-IIS-004 ]
  elb        = data.aws_elb.loadBalancer.id
  count      = length( aws_instance.xxx-IIS-004 )
  instance   = split("_", local.att_004)[count.index]
}