如何忽略 Terraform 中的嵌套字段？

Posted 2023-03-04

【中文标题】如何忽略 Terraform 中的嵌套字段？

【英文标题】：How do you ignore a nested field in Terraform?

【发布时间】：2020-08-14 00:21:45

【问题描述】：

Terraform 新手在这里。我这里有一个 ECS 计划任务的代码。每当我对此进行更改并应用更改时，都会在 ECS 任务中设置任务定义的第一个版本。所以我尝试向它添加生命周期方法。

resource "aws_cloudwatch_event_target" "sqs" 
  rule      = aws_cloudwatch_event_rule.sqs.name
  target_id = local.namespace
  arn       = aws_ecs_cluster.app.arn
  role_arn  = aws_iam_role.ecsRole.arn
  input     = ""

  ecs_target 
    task_count          = 1
    task_definition_arn = aws_ecs_task_definition.sqs.arn
    launch_type         = "FARGATE"
    platform_version    = "LATEST"

    network_configuration 
      security_groups = [aws_security_group.nsg_task.id]
      subnets         = split(",", var.private_subnets)
    
  

试过了：

    resource "aws_cloudwatch_event_target" "sqs" 
      rule      = aws_cloudwatch_event_rule.sqs.name
      target_id = local.namespace
      arn       = aws_ecs_cluster.app.arn
      role_arn  = aws_iam_role.ecsRole.arn
      input     = ""

      ecs_target 
        task_count          = 1
        task_definition_arn = aws_ecs_task_definition.sqs.arn
        launch_type         = "FARGATE"
        platform_version    = "LATEST"

        network_configuration 
          security_groups = [aws_security_group.nsg_task.id]
          subnets         = split(",", var.private_subnets)
        

        lifecycle 
          ignore_changes = [task_definition_arn]
        
      
    

和

resource "aws_cloudwatch_event_target" "sqs" 
  rule      = aws_cloudwatch_event_rule.sqs.name
  target_id = local.namespace
  arn       = aws_ecs_cluster.app.arn
  role_arn  = aws_iam_role.ecsRole.arn
  input     = ""

  ecs_target 
    task_count          = 1
    task_definition_arn = aws_ecs_task_definition.sqs.arn
    launch_type         = "FARGATE"
    platform_version    = "LATEST"

    network_configuration 
      security_groups = [aws_security_group.nsg_task.id]
      subnets         = split(",", var.private_subnets)
    
  

  lifecycle 
    ignore_changes = [ecs_target.task_definition_arn]
  

如何通过生命周期忽略嵌套字段？

【参考方案1】：

找到了解决办法。这行得通

resource "aws_cloudwatch_event_target" "sqs" 
  rule      = aws_cloudwatch_event_rule.sqs.name
  target_id = local.namespace
  arn       = aws_ecs_cluster.app.arn
  role_arn  = aws_iam_role.ecsRole.arn
  input     = ""

  ecs_target 
    task_count          = 1
    task_definition_arn = aws_ecs_task_definition.sqs.arn
    launch_type         = "FARGATE"
    platform_version    = "LATEST"

    network_configuration 
      security_groups = [aws_security_group.nsg_task.id]
      subnets         = split(",", var.private_subnets)
    
  

  lifecycle 
    ignore_changes = [ecs_target.0.task_definition_arn]
  

对我来说不寻常的语法，但就是这样:)。

【讨论】：

这是 0.11 样式的语法，它仍然支持一些向后兼容性。如果新式索引语法感觉不那么不寻常，您也可以写ignore_changes = [ecs_target[0].task_definition_arn]。 :D