Learning CoreDNS

Chapter 4. Managing Zone Data

With traditional DNS servers, such as BIND, administrators usually manage primary zone data as files. More recently, DNS servers have begun to support loading primary zone data from other sources, such as databases.

CoreDNS supports a variety of methods to manage zone data. Some will be very familiar to DNS administrators, like zone data files; others are more modern, such as using Git; whereas some are downright retro (host tables, anyone?). In this chapter, we cover all of them.

Together, these options provide administrators with flexibility and, in some cases, advanced functionality in the mechanism they use to manage zone data. Host tables, for example, provide a simple way to add name-to-address and address-to-name mappings without the overhead of creating and maintaining an entire zone data file. Git, on the other hand, provides distributed version-control capabilities.

Let’s begin with the file plug-in, which supports zone data files. We actually covered this in Chapter 3, but we go through it in more detail here.

The file Plug-in

For an administrator with experience managing zone data files, the file plug-in is probably the most familiar mechanism CoreDNS offers. file configures CoreDNS as the primary DNS server for one or more zones. In its simplest form, the file plug-in takes the syntax shown in Example 4-1.

Example 4-1. Simple file plug-in syntax

file DBFILE [ZONES...]

DBFILE is a zone data file containing resource records. You can ...