Lambda Terraform 12-无法在outputs.tf中放置[count.index]

我对terraform模块化部署是个新手，我正在尝试在负载平衡器后面部署aws lambda。之前，我在尝试执行“terraform验证”时从目标组模块收到这些错误消息

是的，我按照建议的消息将[count.index]放在目标组模块中的依赖项资源上。然而，当我尝试执行“terraform validate”时，它现在给了我指令，让我也在目标组模块的输出文件上添加。传达这一信息：

Error: Missing resource instance key

  on ../modules/target-group/outputs.tf line 6, in output "target_arn":
   6:  value ="${aws_alb_target_group.lambda.arn}"

Because aws_alb_target_group.lambda has "count" set, its attributes must be
accessed on specific instances.


For example, to correlate with indices of a referring resource, use:
    aws_alb_target_group.lambda[count.index]

Error: Reference to "count" in non-counted context

  on ../modules/target-group/outputs.tf line 6, in output "target_arn":
   6:  value ="${aws_alb_target_group.lambda[count.index].arn}"

The "count" object can be used only in "resource" and "data" blocks, and only
when the "count" argument is set.

因此，正如建议的那样，我再次以这种格式修改了输出文件

output "target_arn" {
 value ="${aws_alb_target_group.lambda[count.index].arn}"
}

那么我现在得到的信息是：

Error: Missing resource instance key

  on ../modules/target-group/outputs.tf line 6, in output "target_arn":
   6:  value ="${aws_alb_target_group.lambda.arn}"

Because aws_alb_target_group.lambda has "count" set, its attributes must be
accessed on specific instances.


For example, to correlate with indices of a referring resource, use:
    aws_alb_target_group.lambda[count.index]

Error: Reference to "count" in non-counted context

  on ../modules/target-group/outputs.tf line 6, in output "target_arn":
   6:  value ="${aws_alb_target_group.lambda[count.index].arn}"

The "count" object can be used only in "resource" and "data" blocks, and only
when the "count" argument is set.

他们先前关于添加[count.index]的建议不适用于输出文件。

---

我再也不明白该调整什么，也看不到如何解决问题的在线解决方案。请建议此处需要什么。

使用outputs.tf中的格式修复问题

output "target_arn" {
 value =join("", aws_alb_target_group.lambda[*].arn)
}

另一种指定方法

output "event_bus_arn" {
    value = element(concat(aws_cloudwatch_event_bus.event_bus.*.arn, [""]), 0)
}