nixos-build-vms - Man Page

nixos-build-vms [--show-trace] [--no-out-link] [--help] [--option name value] network​.nix

This command builds a network of QEMU-KVM virtual machines of a Nix expression specifying a network of NixOS machines​. The virtual network can be started by executing the bin/run-vms shell script that is generated by this command​. By default, a result symlink is produced that points to the generated virtual network​.

A network Nix expression has the following structure:

{
  test1 = {pkgs, config, ​.​.​.}:
    {
      services​.openssh​.enable = true;
      nixpkgs​.localSystem​.system = "i686-linux";
      deployment​.targetHost = "test1​.example​.net";

      # Other NixOS options
    };

  test2 = {pkgs, config, ​.​.​.}:
    {
      services​.openssh​.enable = true;
      services​.httpd​.enable = true;
      environment​.systemPackages = [ pkgs​.lynx ];
      nixpkgs​.localSystem​.system = "x86_64-linux";
      deployment​.targetHost = "test2​.example​.net";

      # Other NixOS options
    };
}

Each attribute in the expression represents a machine in the network (e​.g​. test1 and test2) referring to a function defining a NixOS configuration​. In each NixOS configuration, two attributes have a special meaning​. The deployment​.targetHost specifies the address (domain name or IP address) of the system which is used by ssh to perform remote deployment operations​. The nixpkgs​.localSystem​.system attribute can be used to specify an architecture for the target machine, such as i686-linux which builds a 32-bit NixOS configuration​. Omitting this property will build the configuration for the same architecture as the host system​.

This command accepts the following options:

--show-trace

Shows a trace of the output​.

--no-out-link

Do not create a 'result' symlink​.

-h,  --help

Shows the usage of this command to the user​.

--option name value

Set the Nix configuration option name to value​. This overrides settings in the Nix configuration file (see nix.conf(5))​.

Eelco Dolstra

Copyright © 2007-2020 Eelco Dolstra