dnscontrol/docs/getting-started.md

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Getting Started

1. Install the software

You can either download the latest github release, or build from the go source:

go get github.com/StackExchange/dnscontrol

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

2. Create a place for the config files.

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

Note: Do not store your creds.json file in Git unencrypted. That is unsafe. In fact you should include creds.json in your .gitignore file. We recommend you encrypt the file using something like git-crypt or Blackbox.

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.

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-example.txt]({{ site.github.url }}/assets/dnsconfig.js-example.txt)) and renaming it.

The file looks like:

{% highlight js %}

// Providers:

var REG_NONE = NewRegistrar('none', 'NONE'); // No registrar. var DNS_BIND = NewDnsProvider('bind', 'BIND'); // ISC BIND.

// Domains:

D('example.com', REG_NONE, DnsProvider(DNS_BIND), A('@', '1.2.3.4') ); {%endhighlight%}

You may modify this file to match your particular providers and domains. See the javascript docs and the provider docs for more details. If you are using other providers, you will likely need to make a creds.json file with api tokens and other account information. For example, to use both name.com and Cloudflare, you would have:

{% highlight js %} { "cloudflare":{ //provider name to be used in dnsconfig.js "apikey": "key", //API key "apiuser": "username" //username for cloudflare }, "namecom":{ //provider name to be used in dnsconfig.js "apikey": "key", //API Key "apiuser": "username" //username for name.com } } {%endhighlight%}

There are 2 types of providers:

A "Registrar" is who you register the domain with. Start with REG_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.

The DnsProvider is the service that actually provides DNS service (port 53) and may be the same or different company. Even if both your Registrar and DnsProvider are the same company, two different defintions 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-example.txt]({{ site.github.url }}/assets/creds.json-example.txt)) and renaming it.

The file looks like:

{% highlight js %} { "bind": { }, "r53_ACCOUNTNAME": { "KeyId": "change_to_your_keyid", "SecretKey": "change_to_your_secretkey" } } {%endhighlight%}

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

5. Test the sample files.

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

First run dnscontrol preview and make sure that it completes with no errors. The preview command is the "dry run" mode that shows 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.

It should look something like this:

{% highlight js %}

$ 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. {%endhighlight%}

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.

{% highlight js %} $ 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. {%endhighlight%}

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:

{% highlight js %} $ 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. {%endhighlight%}

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 do 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:

{% highlight js %} $TTL 300 @ IN SOA DEFAULT_NOT_SET. DEFAULT_NOT_SET. 1 3600 600 604800 1440 IN A 10.10.10.10 {%endhighlight%}

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 feature 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 convertzone utility that is included in the DNSControl repo (it converts BIND-style zone files to DNSControl's language).

Now you can make change 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.
• Use a CI/CD tool like Jenkins to automatically push DNS changes.
• Join the DNSControl community. File issues and PRs.