nixpkgs/nixos/doc/manual/development/building-nixos.xml

<chapter xmlns="http://docbook.org/ns/docbook"
        xmlns:xlink="http://www.w3.org/1999/xlink"
        xmlns:xi="http://www.w3.org/2001/XInclude"
        version="5.0"
        xml:id="sec-building-cd">
 <title>Building Your Own NixOS CD</title>
 <para>
  Building a NixOS CD is as easy as configuring your own computer. The idea is to use another module which will replace your <filename>configuration.nix</filename> to configure the system that would be installed on the CD.
 </para>
 <para>
  Default CD/DVD configurations are available inside <filename>nixos/modules/installer/cd-dvd</filename>.
<screen>
<prompt>$ </prompt>git clone https://github.com/NixOS/nixpkgs.git
<prompt>$ </prompt>cd nixpkgs/nixos
<prompt>$ </prompt>nix-build -A config.system.build.isoImage -I nixos-config=modules/installer/cd-dvd/installation-cd-minimal.nix default.nix</screen>
 </para>
 <para>
  Before burning your CD/DVD, you can check the content of the image by mounting anywhere like suggested by the following command:
<screen>
<prompt># </prompt>mount -o loop -t iso9660 ./result/iso/cd.iso /mnt/iso</screen>
 </para>
</chapter>