dnscontrol/documentation/getting-started.md
Tom Whitwell b91bcf373f
Add Shell Completion script generation
`dnsutils shell-completion <shell>` will generate a shell completion
script for the specified shell (bash or zsh). If no shell is specified,
the script will be generated for the current shell, using `$SHELL`.
2023-10-15 11:12:28 +01:00

10 KiB

Getting Started

1. Install the software

Choose one of the following installation methods:

Homebrew

On macOS (or Linux) you can install it using Homebrew.

brew install dnscontrol

MacPorts

Alternatively on macOS you can install it using MacPorts.

sudo port install dnscontrol

Docker

You can use DNSControl locally using the Docker image from Docker hub or GitHub Container Registry and the command below.

docker run --rm -it -v "$(pwd):/dns"  ghcr.io/stackexchange/dnscontrol preview

Binaries

Download binaries from GitHub for Linux (binary, tar, RPM, DEB), FreeBSD (tar), Windows (exec, ZIP) for 32-bit, 64-bit, and ARM.

Source

DNSControl can be built from source with Go version 1.18 or higher.

The go install command will download the source, compile it, and install dnscontrol in your $GOBIN directory.

To install, simply run

go install github.com/StackExchange/dnscontrol/v4@latest

To download the source

git clone https://github.com/StackExchange/dnscontrol

If these don't work, more info is in #805.

1.1. Shell Completion

Shell completion is available for zsh and bash.

zsh

Add eval "$(dnscontrol shell-completion zsh)" to your ~/.zshrc file.

This requires completion to be enabled in zsh. A good tutorial for this is available at The Valuable Dev [archived].

bash

Add eval "$(dnscontrol shell-completion bash)" to your ~/.bashrc file.

This requires the bash-completion package to be installed. See scop/bash-completion for instructions.

2. Create a place for the config files

Create a directory where you'll store your configuration files. We highly recommend storing these files in a Git repo, but for simple tests anything will do.

Create a subdirectory called zones in the same directory as the configuration files. (mkdir zones). zones is where the BIND provider writes the zonefiles it creates. Even if you don't use BIND for DNS service, it is useful for testing.

3. Create the initial dnsconfig.js

dnsconfig.js is the main configuration and defines providers, DNS domains, and so on.

Start your dnsconfig.js file by downloading dnsconfig.js and renaming it.

The file looks like:

{% code title="dnsconfig.js" %}

var REG_NONE = NewRegistrar("none");
var DNS_BIND = NewDnsProvider("bind");

D("example.com", REG_NONE, DnsProvider(DNS_BIND),
    A("@", "1.2.3.4")
);

{% endcode %}

Modify this file to match your particular providers and domains. See the DNSConfig docs and the provider docs for more details.

Create a file called creds.json for storing provider configurations (API tokens and other account information). For example, to use both name.com and Cloudflare, you would have:

{% code title="creds.json" %}

{
  "cloudflare": {                               // The provider name used in dnsconfig.js
    "TYPE": "CLOUDFLAREAPI",                    // The provider type identifier
    "accountid": "your-cloudflare-account-id",  // credentials
    "apitoken": "your-cloudflare-api-token"     // credentials
  },
  "namecom": {                                  // The provider name used in dnsconfig.js
    "TYPE": "NAMEDOTCOM",                       // The provider type identifier
    "apikey": "key",                            // credentials
    "apiuser": "username"                       // credentials
  },
  "none": { "TYPE": "NONE" }                    // The no-op provider
}

{% endcode %}

Note: Do not store your creds.json file in Git unencrypted. That is unsafe. Add creds.json to your .gitignore file as a precaution. This file should be encrypted using something like git-crypt or Blackbox.

There are 2 types of providers:

A "Registrar" is with whom you register the domain. Start with NONE, which is a provider that never talks to or updates the registrar. You can define your registrar later when you want to use advanced features.

A "DnsProvider" is the service that actually provides DNS service (port 53) and may be the same or a different registrar. Even if both your Registrar and DnsProvider are the same company, two different definitions must be included in dnsconfig.js.

4. Create the initial creds.json

creds.json stores credentials and a few global settings. It is only needed if any providers require credentials (API keys, usernames, passwords, etc.).

Start your creds.json file by downloading creds.json and renaming it.

The file looks like:

{% code title="creds.json" %}

{
  "bind": {
    "TYPE": "BIND"
  },
  "r53_accountname": {
    "TYPE": "ROUTE53",
    "KeyId": "change_to_your_keyid",
    "SecretKey": "change_to_your_secretkey"
  }
}

{% endcode %}

Ignore the r53_accountname section. It is a placeholder and will be ignored. You can use it later when you define your first set of API credentials.

Note that creds.json is a JSON file. JSON is very strict about commas and other formatting. There are a few different ways to check for typos:

Python:

python -m json.tool creds.json

jq:

jq . < creds.json

FYI: creds.json fields can be read from an environment variable. The field must begin with a $ followed by the variable name. No other text. For example:

{% code title="creds.json" %}

{
  "apikey": "$GANDI_V5_APIKEY"
}

{% endcode %}

5. Test the sample files

Before you edit the sample files, verify that the system is working.

First run dnscontrol preview and ensure it completes without error(s). The preview command is the "dry run" mode that shows only what changes need to be made and never makes any actual changes. It will use APIs if needed to find out what DNS entries currently exist.

(All output assumes the --full flag)

It should look something like this:

dnscontrol preview
Initialized 1 registrars and 1 dns service providers.
******************** Domain: example.com
----- Getting nameservers from: bind
----- DNS Provider: bind... 1 correction
#1: GENERATE_ZONEFILE: example.com
 (2 records)

----- Registrar: none
Done. 1 corrections.

Next, run dnscontrol push to actually make the changes. In this case, the change will be to create a zone file where one didn't previously exist.

dnscontrol push
Initialized 1 registrars and 1 dns service providers.
******************** Domain: example.com
----- Getting nameservers from: bind
----- DNS Provider: bind... 1 correction
#1: GENERATE_ZONEFILE: example.com
 (2 records)

CREATING ZONEFILE: zones/example.com.zone
SUCCESS!
----- Registrar: none
Done. 1 corrections.

6. Make a change

Try making a change to dnsconfig.js. For example, change the IP address of in A("@", "1.2.3.4") or add an additional A record.

In our case, we changed the IP address to 10.10.10.10. Previewing our change looks like this:

dnscontrol preview
Initialized 1 registrars and 1 dns service providers.
******************** Domain: example.com
----- Getting nameservers from: bind
----- DNS Provider: bind... 1 correction
#1: GENERATE_ZONEFILE: example.com
MODIFY A example.com: (1.2.3.4 300) -> (10.10.10.10 300)

----- Registrar: none
Done. 1 corrections.

Notice that it read the old zone file and was able to produce a "diff" between the old A record and the new one. If the zonefile didn't exist, the output would look different because the zone file was being created from scratch.

Run dnscontrol push to see the system generate a new zone file.

Other providers use an API to do updates. In those cases the individual changes will translate into API calls that update the specific records.

Take a look at the zones/example.com.zone file. It should look like:

$TTL 300
@                IN SOA   DEFAULT_NOT_SET. DEFAULT_NOT_SET. 1 3600 600 604800 1440
                 IN A     10.10.10.10

You can change the "DEFAULT_NOT_SET" text by following the documentation for the BIND provider to set the "master" and "mbox" settings. Try that now.

7. Use your own domains

Now that we know the system is working for test data, try controlling a real domain (or a test domain if you have one).

Set up the provider: Add the providers's definition to dnsconfig.js and list any credentials in creds.json. Each provider is different. See the provider docs for specifics.

Edit the domain: Add the D() entry for the domain, or repurpose the example.com domain. Add individual A(), MX() and other records as needed. Remember that the first parameter to D() is always a Registrar.

Run dnscontrol preview to test your work. It may take a few tries to list all the DNS records that make up the domain. When preview shows no changes required, then you know you are at record parity.

The Migrating doc has advice about converting from other systems. You can manually create the D() statements, or you can generate them automatically using the dnscontrol get-zones command to import the zone from (most) providers and output it as code that can be added to dnsconfig.js and used with very little modification.

Now you can make changes to the domain(s) and run dnscontrol preview

8. Production Advice

If you are going to use this in production, we highly recommend the following:

  • Store the configuration files in Git.
  • Encrypt the creds.json file before storing it in Git. Do NOT store API keys or other credentials without encrypting them.
  • Use a CI/CD tool like GitLab, Jenkins, CircleCI, GitHub Actions, etc. to automatically push DNS changes.
  • Join the DNSControl community. File issues and PRs.