route53 and cloudformation

Problem and Audience

Managing route53 records with cloudformation is a good idea for the same reasons that tracking other resources with cloudformation (or terraform or whatever) is better than clicking around in the web console - namely:

• it is less work to manipulate route53 records by editing json files than clicking through the web console
• tracking the cloudformation template and parameters in git (or whatever code repository) gives an audit trail
• cloudformation makes automation easy

We setup the following cloudformation template to start managing our simple route53 zones with cloudformation. The template takes advantage of the nunjucks extensions to cloudformation templates supported by our little stack automation.

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Parameters": {
    "DomainName": {
      "Type": "String",
      "Description": "the domain name"
    }
  },
  "Resources": {
    "HostedZone": {
      "Type" : "AWS::Route53::HostedZone",
      "Properties" : {
          "HostedZoneTags" : [ 
            {{ stackTagsStr }}
          ],
          "Name" : { "Ref": "DomainName" }
        }
    }

    {% if stackVariables.aliasList.length %}
    ,
      {% for item in stackVariables.aliasList %}
      "AliasA{{ item.resourceName }}": {
        "Type" : "AWS::Route53::RecordSet",
        "Properties" : {
            "AliasTarget" : {
              "DNSName" : "{{ item.target }}",
              "HostedZoneId": "{{ item.hostedZoneId }}"
            },
            "Comment" : "{{ item.comment }}",
            "HostedZoneId" : { "Ref": "HostedZone" },
            "Name" : "{{ item.domainName }}",
            "Type" : "A"
          }
      },
      "AliasAaaa{{ item.resourceName }}": {
        "Type" : "AWS::Route53::RecordSet",
        "Properties" : {
            "AliasTarget" : {
              "DNSName" : "{{ item.target }}",
              "HostedZoneId": "{{ item.hostedZoneId }}"
            },
            "Comment" : "{{ item.comment }}",
            "HostedZoneId" : { "Ref": "HostedZone" },
            "Name" : "{{ item.domainName }}",
            "Type" : "AAAA"
          }
      }

      {% if not loop.last %} , {% endif %}
      {% endfor %}
    {% endif %}

    {% if stackVariables.mxConfig %}
    ,
    "MX": {
      "Type" : "AWS::Route53::RecordSet",
      "Properties" : {
          "Comment" : "mx mail config",
          "HostedZoneId" : { "Ref": "HostedZone" },
          "Name" : { "Ref": "DomainName" },
          "ResourceRecords" : {{ stackVariables.mxConfig.resourceRecords | dump }},
          "TTL" : "900",
          "Type" : "MX"
        }
    }
    {% endif %}

    {% if stackVariables.cnameList.length %}
    ,
    {% for item in stackVariables.cnameList %}
    "Cname{{item.resourceName}}": {
      "Type" : "AWS::Route53::RecordSet",
      "Properties" : {
          "Comment" : "{{ item.comment }}",
          "HostedZoneId" : { "Ref": "HostedZone" },
          "Name" : "{{ item.domainName }}",
          "ResourceRecords" : [ "{{ item.target }}" ],
          "TTL" : "900",
          "Type" : "CNAME"
        }
    }
    {% if not loop.last %} , {% endif %}
    {% endfor %}

    {% endif %}

    {% if stackVariables.txtList.length %}
    ,
    {% for item in stackVariables.txtList %}
    "Txt{{item.resourceName}}": {
      "Type" : "AWS::Route53::RecordSet",
      "Properties" : {
          "Comment" : "{{ item.comment }}",
          "HostedZoneId" : { "Ref": "HostedZone" },
          "Name" : { "Ref": "DomainName" },
          "ResourceRecords" : [ {{ item.txtValue | dump }} ],
          "TTL" : "900",
          "Type" : "TXT"
        }
    }
    {% if not loop.last %} , {% endif %}
    {% endfor %}

    {% endif %}

  },

  "Outputs": {
    "NameServers": {
      "Description": "hosted zone nameservers",
      "Value": { "Fn::Join": [",", { "Fn::GetAtt": [ "HostedZone", "NameServers" ] }] }
    }
  }
}

Summary

Managing route53 zones with cloudformation is the right thing to do.