AWS Route53子域名alb.skhole.club无DNS记录问题求助

问题背景 #

在AWS Route53中购买域名skhole.club，系统自动生成对应托管区域；随后为子域名alb.skhole.club创建了独立托管区域，通过Terraform配置添加DNS记录。执行dig命令查询skhole.club可正常返回记录，但查询alb.skhole.club无任何结果。首次使用自定义域名，寻求排查思路及解决方案。

Terraform配置文件(route53.tf) #

版本声明 #

required_providers {
  aws = {
    source  = "hashicorp/aws"
    version = "4.59.0"
  }
}

资源配置 #

data "aws_route53_zone" "host_domain" {
  name = local.host_domain
}

data "aws_route53_zone" "alb" {
  name = "alb.${local.host_domain}"
}

resource "aws_route53_record" "cert_validation" {
  for_each = {
    for dvo in aws_acm_certificate.cert.domain_validation_options : dvo.domain_name => {
      name   = dvo.resource_record_name
      record = dvo.resource_record_value
      type   = dvo.resource_record_type
    }
  }

  allow_overwrite = true
  name            = each.value.name
  records         = [each.value.record]
  ttl             = 60
  type            = each.value.type
  zone_id         = data.aws_route53_zone.host_domain.zone_id
}

resource "aws_route53_record" "cert_alb" {
  for_each = {
    for dvo in aws_acm_certificate.cert.domain_validation_options : dvo.domain_name => {
      name   = dvo.resource_record_name
      record = dvo.resource_record_value
      type   = dvo.resource_record_type
    } if length(regexall("^\\*\\.", dvo.domain_name)) == 0
  }

  allow_overwrite = true
  name            = each.value.name
  records         = [each.value.record]
  ttl             = 60
  type            = each.value.type
  zone_id         = data.aws_route53_zone.alb.zone_id
}

resource "aws_acm_certificate" "cert" {
  domain_name               = local.host_domain
  subject_alternative_names = ["alb.${local.host_domain}"]
  validation_method         = "DNS"

  tags = {
    Environment = var.app_environment
  }

  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_acm_certificate_validation" "cert" {
  certificate_arn         = aws_acm_certificate.cert.arn
  validation_record_fqdns = [for record in aws_route53_record.cert_validation : record.fqdn]
}

resource "aws_acm_certificate_validation" "alb" {
  certificate_arn         = aws_acm_certificate.cert.arn
  validation_record_fqdns = [for dvo in aws_acm_certificate.cert.domain_validation_options : dvo.resource_record_name]
}

resource "aws_route53_record" "site" {
  zone_id = data.aws_route53_zone.host_domain.zone_id
  name    = local.host_domain
  type    = "A"

  alias {
    name                   = aws_cloudfront_distribution.static-skhole.domain_name
    zone_id                = aws_cloudfront_distribution.static-skhole.hosted_zone_id
    evaluate_target_health = false
  }
}

resource "aws_route53_record" "alb" {
  zone_id = data.aws_route53_zone.alb.zone_id
  name    = "alb.${local.host_domain}"
  type    = "A"

  alias {
    name                   = aws_lb.application_load_balancer.dns_name
    zone_id                = aws_lb.application_load_balancer.zone_id
    evaluate_target_health = false
  }
}

Route53控制台状态 #

• skhole.club托管区域：
• alb.skhole.club独立托管区域：

dig命令执行结果 #

查询主域名skhole.club #

> dig skhole.club ns +short
ns-306.awsdns-38.com.
ns-1898.awsdns-45.co.uk.
ns-1111.awsdns-10.org.
ns-526.awsdns-01.net.

查询子域名alb.skhole.club（无返回结果） #

> dig alb.skhole.club ns +short

问题根源与解决方案 #

问题根源 #

为子域名alb.skhole.club创建独立托管区域后，未在主域名skhole.club的托管区域中添加NS记录指向子区域的DNS服务器，导致全球DNS系统无法定位到子域名的解析入口。

解决方案 #

无需为子域名创建独立托管区域，直接将alb.skhole.club的DNS记录添加至主域名skhole.club的托管区域中即可。

内容的提问来源于stack exchange，提问作者Asuha