Non-Switchable Systems for Image-Based Appliances

nixos/doc/manual/development/non-switchable-systems.section.md

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# Non Switchable Systems {#sec-non-switchable-system}

In certain systems, most notably image based appliances, updates are handled
outside the system. This means that you do not need to rebuild your
configuration on the system itself anymore.

If you want to build such a system, you can use the `image-based-appliance`
profile:

```nix
{ modulesPath, ... }: {
  imports = [ "${modulesPath}/profiles/image-based-appliance.nix" ];
}
```

The most notable deviation of this profile from a standard NixOS configuration
is that after building it, you cannot switch *to* the configuration anymore.
The profile sets `config.system.switch.enable = false;`, which excludes
`switch-to-configuration`, the central script called by `nixos-rebuild`, from
your system. Removing this script makes the image lighter and slightly more
secure.

Chunks

b11b5137 (1st chunk of `nixos/doc/manual/development/non-switchable-systems.section.md`)

Title: Non-Switchable Systems for Image-Based Appliances

Summary

This section describes how to create a non-switchable NixOS system, typically used for image-based appliances where updates are handled externally. By using the `image-based-appliance` profile, you can build a system where switching to a new configuration is disabled, making the image lighter and more secure. This is achieved by setting `config.system.switch.enable = false`, which removes the `switch-to-configuration` script.