Creating a NixOS live CD: Difference between revisions

Revision as of 18:35, 21 August 2017

motivation

creating a modified NIXOS live CD out of a working nixos installation gives you the benefits:

verify what is included
no need to download it
it is easy to add your own programs to the image

how to build your own image

Create a file "iso.nix":

# This module defines a small NixOS installation CD.  It does not
# contain any graphical stuff.
{config, pkgs, ...}:
{
  imports = [
     <nixpkgs/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix>
     <nixpkgs/nixos/modules/installer/cd-dvd/channel.nix>
  ];
}

Build the image via:

 nix-build -A config.system.build.isoImage -I nixos-config=iso.nix  /path/to/nixpkgs/nixos

=== Start SSH with your SSH key

In your iso.nix:

 services.openssh = {
   enable = true;
   hostKeys = [
     { bits = 8192; type = "ed25519"; path = "/etc/ssh/ssh_host_ed25519_key"; }
   ];
 };
 # enable ssh in the iso boot process
 systemd.services.sshd.wantedBy = lib.mkForce [ "multi-user.target" ];
 users.users.root.openssh.authorizedKeys.keys [
   "ssh-rsa AAAAB3NzaC1y...== me@my-laptop"
 ];

software installation inside the 'once' deployed and booted image

in case you have booted from your image you can add software as described here:

install/remove software

references

See also section "Building your own NixOS CD" of the NixOS manual.

@@ Line 6: / Line 6: @@
 * it is easy to add your own programs to the image
-== how to build such an image ==
+== how to build your own image ==
-we will use the NIXREPOS variable, which points to the nixpkgs/nixos checkouts, see [[Create and debug nix packages]]
-just run this command (for 64 bit):
+Create a file "iso.nix":
- export NIX_PATH=$NIXREPOS
- nix-build -A iso_graphical.x86_64-linux $NIXREPOS/nixos/release.nix
-for 32 bit:
- export NIX_PATH=$NIXREPOS
- nix-build -A iso_graphical.i686-linux $NIXREPOS/nixos/release.nix
-once the building process is over, you should see multiple nix distributions built (for multiple archs). See contents to find iso image path:
- $ cat /nix/store/2y4bivmrzg4d2dgby2b7prvfj7445088-nixos-iso-0.1pre1234/nix-support/hydra-build-products
- file iso /nix/store/94rrfklbk2hcqhkr4627vsrlprlyva50-iso9660-image/iso/nixos-minimal-0.1pre1234-i686-linux-test.iso
-and copy the new image from there to your USB drive (or use unetbootin).
-== adding additional software to the image ==
-the basic script '''/etc/nixos/nixos/release.nix''' contains several entry points for custom images. as we are using '''-A iso_minimal''' have a look at: iso_minimal which will redirect us to:
-* ./modules/installer/cd-dvd/installation-cd-minimal.nix -> /etc/nixos/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix
   # This module defines a small NixOS installation CD.  It does not
   # contain any graphical stuff.
   {config, pkgs, ...}:
   {
-    require = [
+    imports = [
-     ./installation-cd-base.nix
+      <nixpkgs/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix>
-     ../../profiles/minimal.nix
+      <nixpkgs/nixos/modules/installer/cd-dvd/channel.nix>
     ];
   }
+Build the image via:
+  nix-build -A config.system.build.isoImage -I nixos-config=iso.nix  /path/to/nixpkgs/nixos
 === Start SSH with your SSH key
-In your configuration.nix:
+In your iso.nix:
 <code>