循环遍历列表映射以在一个资源块中为多个域创建 DNS 记录

Posted 2023-03-24

【中文标题】循环遍历列表映射以在一个资源块中为多个域创建 DNS 记录

【英文标题】：Loop through map of lists to create DNS records for multiple domains in one resource block

【发布时间】：2021-12-23 19:13:49

【问题描述】：

我有几个域，我想创建尽可能多的 DRY 子域。这是原始结构：

variable "domain1" 
  type = list(string)
  default = ["www", "www2"]


variable "domain2" 
  type = list(string)
  default = ["www3", "www1"]


resource "aws_route53_record" "domain1" 
  for_each = toset(var.domain1)
  
  type = "A"
  name = "$each.key.domain1.com"
  zone_id = ""


resource "aws_route53_record" "domain2" 
  for_each = toset(var.domain2)
  
  type = "A"
  name = "$each.key.domain2.com"
  zone_id = ""

我想组合成一个变量和一个资源块：

variable "subdomains" 
  type = map(list(string))
  default = 
    "domain1.com" = ["www", "www2"]
    "domain2.com" = ["www3", "www1"]
  


resource "aws_route53_record" "domain1" 
  for_each = var.subdomains // make magic happen here...
  
  type = "A"
  name = "$each.subdomain_part.$each.domain_part" // ...and here
  zone_id = ""

有没有办法做到这一点？

【问题讨论】：

如果您有两个不同的域domain1.com 和domain2.com，我假设它们也有两个不同的zone_id，对吧？因此，我认为要概括这一点，您需要某种方式来了解或动态生成区域 ID，以实现完整的工作解决方案。 ??????

不过，这很容易。只是使用相同变量循环通过 aws_route53_zone 数据资源

【参考方案1】：

您可以按如下方式展平您的var.subdomains：

locals 
    subdomains_flat = flatten([for domain, subdomains in var.subdomains:
                        [ for subdomain in subdomains:
                            
                                domain_part = domain
                                subdomain_part = subdomain
                            
                        ]
                      ])

然后：

resource "aws_route53_record" "domain1" 
  for_each = for idx, val in local.subdomains_flat: idx => val 
  
  type = "A"
  name = "$each.value.subdomain_part.$each.value.domain_part" 
  zone_id = ""

【讨论】：

这行得通，但会造成相当混乱的状态，因为索引用于资源名称。是否可以对其进行调整，以便在资源名称中使用子域？

@aardbol 索引必须是唯一的，不能保证子域将是唯一的，而不是 subdomains_flat 数组，您可以构建适合您需要的自定义地图以获得更好看的索引

【参考方案2】：

跟进the comment关于混乱状态的信息，我不会说混乱......但肯定有一些缺点，该答案中的索引是数字，计划显示资源结束：

  # aws_route53_record.domain1["0"] will be created
  + resource "aws_route53_record" "domain1" 

  # aws_route53_record.domain1["1"] will be created
  + resource "aws_route53_record" "domain1" 

当我们在列表中添加或删除子域时，这可能会产生问题，顺序可能会发生变化，这将导致资源被破坏和重新创建，这对 route53 记录不理想...

---

这是另一种在资源名称中创建不同索引的方法。 我们仍然使用 flatten 来提取子域，但在这种情况下，我会立即连接，该局部变量已准备好供 aws_route53_record 资源使用。

provider "aws" 
  region = "us-east-2"


variable "subdomains" 
  type = map(list(string))
  default = 
    "domain1.com" = ["www", "www2"]
    "domain2.com" = ["www3", "www1"]
  


locals 
  records = flatten([for d, subs in var.subdomains: [for s in subs: "$s.$d"]])


resource "aws_route53_record" "domain1" 
  for_each = toset(local.records)

  type    = "A"
  name    = each.value
  zone_id = "us-east-1"

一个 terraform 计划如下所示：

Terraform will perform the following actions:

  # aws_route53_record.domain1["www.domain1.com"] will be created
  + resource "aws_route53_record" "domain1" 
      + allow_overwrite = (known after apply)
      + fqdn            = (known after apply)
      + id              = (known after apply)
      + name            = "www.domain1.com"
      + type            = "A"
      + zone_id         = "us-east-1"
    

  # aws_route53_record.domain1["www1.domain2.com"] will be created
  + resource "aws_route53_record" "domain1" 
      + allow_overwrite = (known after apply)
      + fqdn            = (known after apply)
      + id              = (known after apply)
      + name            = "www1.domain2.com"
      + type            = "A"
      + zone_id         = "us-east-1"
    
    ...