Comprehensive Guide to DNSControl

Table of Contents

1. Introduction to DNSControl
2. Key Features of DNSControl
3. How DNSControl Works
4. DNSControl Workflow
5. Understanding DNSControl Terminology
6. Step-by-Step Tutorial: Setting Up DNSControl

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1. Introduction to DNSControl

DNSControl is an open-source tool developed by Stack Exchange to manage DNS zones across multiple providers using a declarative, code-driven approach. It allows system administrators and DevOps teams to define DNS records in a high-level configuration file, which can then be pushed to various DNS providers. This approach brings version control, automation, and consistency to DNS management. (Bytebase, GitHub)

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2. Key Features of DNSControl

• Multi-Provider Support: DNSControl supports over 35 DNS providers, including AWS Route 53, Cloudflare, Google DNS, and BIND. (DNSControl)
• Declarative Configuration: DNS records are defined using a JavaScript-like Domain Specific Language (DSL), making configurations readable and maintainable.(SphericalKat)
• Version Control Integration: Configurations are stored in files compatible with Git, enabling history tracking, collaboration, and rollback capabilities.
• Automation and CI/CD: Supports automated deployments and testing, allowing DNS changes to be part of a continuous integration pipeline.(DNSControl)
• Extensibility: The provider model is extensible, allowing the addition of new DNS providers and registrars as needed.(SphericalKat)
• Cloudflare Integration: Direct control over Cloudflare settings, including enabling/disabling the “orange cloud” proxy feature.(DNSControl)

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3. How DNSControl Works

DNSControl operates through a two-step process:

1. Configuration: Users define their DNS records in a dnsconfig.js file using the DSL. This file specifies domains, record types, TTLs, and associated providers.(DigitalOcean)
2. Execution: The dnscontrol command-line tool processes the configuration file and applies the changes to the specified DNS providers. The tool supports commands like preview to simulate changes and push to apply them. (Server Fault Blog)

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4. DNSControl Workflow

A typical workflow with DNSControl involves:

• Define: Create or update the dnsconfig.js file to reflect desired DNS records.
• Preview: Run dnscontrol preview to see a simulation of the changes without applying them.
• Review: Examine the output for any errors or unintended changes.
• Push: Execute dnscontrol push to apply the changes to the live DNS providers.(DigitalOcean)
• Monitor: Verify the changes using DNS lookup tools like dig or through the provider’s dashboard.

This workflow ensures that DNS changes are deliberate, tested, and traceable.(DigitalOcean)

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5. Understanding DNSControl Terminology

• Registrar: An entity responsible for managing domain registrations. In DNSControl, registrars are defined using NewRegistrar().(Zeller.sh)
• DNS Provider: A service that hosts DNS records for domains. Defined using NewDnsProvider().(Zeller.sh)
• Domain: A specific DNS zone, such as example.com, managed within DNSControl.(DigitalOcean)
• Record Types: DNS entries like A, AAAA, MX, CNAME, TXT, etc., defined using functions like A(), AAAA(), MX(), etc.
• TTL (Time to Live): The duration for which a DNS record is cached, specified using TTL().
• Macros and Variables: Reusable values or functions that simplify configurations and ensure consistency.

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6. Step-by-Step Tutorial: Setting Up DNSControl

Prerequisites

• A domain registered with a supported registrar.(DigitalOcean)
• A DNS provider account (e.g., Cloudflare, AWS Route 53).(GitHub)
• A server or local machine with Go installed.(DigitalOcean)

Installation

1. Install Go: Ensure Go version 1.18 or higher is installed on your system.(GitHub)
2. Install DNSControl: Run the following command to install DNSControl: go install github.com/StackExchange/dnscontrol/v3@latest

3. Verify Installation: Check the installed version:(DigitalOcean) dnscontrol version

Configuration

# Configuration

## Create Configuration Directory:
mkdir ~/dnscontrol
cd ~/dnscontrol

## Define Providers: In dnsconfig.js, define the registrar and DNS provider:
var REG_NAMECOM = NewRegistrar('name.com');
var DNS_CLOUDFLARE = NewDnsProvider('cloudflare');

## Define Domain and Records:
D('example.com', REG_NAMECOM, DnsProvider(DNS_CLOUDFLARE),
  A('@', '192.0.2.1'),
  CNAME('www', '@'),
  MX('@', 10, 'mail.example.com.')
);

## Configure Credentials: Create a creds.json file with your provider credentials:
{
  "cloudflare": {
    "TYPE": "CLOUDFLAREAPI",
    "accountid": "<account-id>",
    "apitoken": "<api-token>"
  }
}

# Deployment

## Preview Changes: Simulate the changes without applying them:
dnscontrol preview

## Apply Changes: Push the changes to the DNS provider:
dnscontrol push

## Verify Changes: Check the DNS records using dig or through the provider's dashboard.

Deployment

1. Preview Changes: Simulate the changes without applying them:(etoews) dnscontrol preview

2. Apply Changes: Push the changes to the DNS provider:(Server Fault Blog) dnscontrol push

3. Verify Changes: Check the DNS records using dig or through the provider’s dashboard.

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Additional Resources

• Official Documentation: For detailed information and advanced configurations, refer to the DNSControl Documentation.
• GitHub Repository: Access the source code and contribute to the project on GitHub.(GitHub)
• Community Discussions: Engage with the community and seek support through Stack Overflow.

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By adopting DNSControl, organizations can streamline their DNS management processes, reduce errors, and enhance collaboration through version-controlled configurations. Its extensibility and automation capabilities make it a valuable tool for modern infrastructure management.

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DNSControl dnsconfig.js Tutorial

🧩 What is dnsconfig.js?

dnsconfig.js is the configuration file used by DNSControl, an infrastructure-as-code tool for managing DNS records in code, across multiple DNS providers like Google Cloud DNS, AWS Route 53, Cloudflare, and more.

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📑 Core Block Types

Block / Function	Purpose
NewRegistrar()	Defines your domain registrar (e.g., Namecheap, GoDaddy)
NewDnsProvider()	Defines your DNS provider (e.g., Cloudflare, GCP, AWS)
D()	Declares a DNS zone (domain) and its records
TTL()	Sets TTL (Time To Live) in seconds
Record functions	Add DNS records like A, CNAME, MX, TXT, NS, SRV, CAA, PTR

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📑 Example DNS Records in Code

Record Type	Example JS Code
A	A("www", "192.0.2.1")
CNAME	CNAME("blog", "gh-pages.github.com.")
MX	MX("@", 10, "mail1.example.com.")
TXT	TXT("@", "v=spf1 include:_spf.google.com ~all")
NS	NS("staging", ["ns1.example.com.", "ns2.example.com."])
CAA	CAA("@", "issue", "letsencrypt.org")

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✅ Setup DNS Providers and Registrar

var REG_NONE = NewRegistrar("none", "NONE"); // No registrar automation
var GCLOUD = NewDnsProvider("gcp", "GCP"); // Google Cloud DNS
var CLOUDFLARE = NewDnsProvider("cf", "CLOUDFLAREAPI"); // Cloudflare

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🧠 Full dnsconfig.js with Multi-Zone Example

// Define DNS providers
var REG_NONE = NewRegistrar("none", "NONE");
var GCLOUD = NewDnsProvider("gcp", "GCP");
var CLOUDFLARE = NewDnsProvider("cf", "CLOUDFLAREAPI");

// -------------------------------------
// DevOpsSchool.com - Root domain on Google Cloud DNS
// -------------------------------------
D("DevOpsSchool.com", REG_NONE, DnsProvider(GCLOUD),
  A("@", "192.0.2.1"),                         // Root domain
  A("api", "192.0.2.2"),                       // api.DevOpsSchool.com
  CNAME("www", "DevOpsSchool.com."),          // www -> root
  TXT("@", "v=spf1 include:_spf.google.com ~all"), // SPF
  MX("@", 10, "aspmx.l.google.com."),         // Mail
  MX("@", 20, "alt1.aspmx.l.google.com."),
  CAA("@", "issue", "letsencrypt.org"),       // SSL CAA
  NS("staging", ["ns1.stagingdns.com.", "ns2.stagingdns.com."]) // Delegate staging
);

// -------------------------------------
// evp.DevOpsSchool.com - Separate subdomain zone on Cloudflare
// -------------------------------------
D("evp.DevOpsSchool.com", REG_NONE, DnsProvider(CLOUDFLARE),
  A("@", "198.51.100.1"),
  CNAME("app", "evp.DevOpsSchool.com."),
  TXT("_acme-challenge", "xyz123-challenge-value"),
  NS("uat", ["ns1.uat-zone.net.", "ns2.uat-zone.net."]), // Delegate uat
  NS("stg.aws", [
    "ns-123.awsdns-45.com.",
    "ns-456.awsdns-78.net.",
    "ns-789.awsdns-12.co.uk.",
    "ns-321.awsdns-34.org."
  ])
);

// -------------------------------------
// uat.evp.DevOpsSchool.com - Separate zone on Google Cloud DNS
// -------------------------------------
D("uat.evp.DevOpsSchool.com", REG_NONE, DnsProvider(GCLOUD),
  A("@", "198.51.100.100"),
  A("api", "198.51.100.101"),
  TXT("@", "uat-verification=token-uat-abc")
);

// -------------------------------------
// RajeshKumar.xyz - Production zone
// -------------------------------------
D("RajeshKumar.xyz", REG_NONE, DnsProvider(GCLOUD),
  A("@", "203.0.113.5"),
  MX("@", 10, "mail.RajeshKumar.xyz."),
  TXT("@", "google-site-verification=abc123"),
  CNAME("support", "zendesk.example.com.")
);

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🧪 Practical Use

Command	Purpose
dnscontrol preview	Shows what changes will be made
dnscontrol push	Applies DNS changes

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🔍 Key Concepts Demonstrated

Concept	Present in Example?	Notes
Multiple providers	✅ Yes	Google Cloud DNS, Cloudflare
Multiple zones/domains	✅ Yes	DevOpsSchool.com, RajeshKumar.xyz
Subdomain delegation via NS	✅ Yes	staging, uat, stg.aws subdomain zones
A/CNAME/MX/TXT/CAA records	✅ Yes	All record types demonstrated
Real-world structure	✅ Yes	Mimics staging/uat/production setup