### Example Snapper Configuration

Source: https://nixos.org/manual/nixos/stable/release-notes

This snippet shows an example configuration for the Snapper service, demonstrating how to set subvolumes and allowed users.

```nix
{
  services.snapper.configs.example = {
    SUBVOLUME = "/example";
    ALLOW_USERS = [ "alice" ];
  };
}
```

--------------------------------

### Snapper Configuration Migration Example

Source: https://nixos.org/manual/nixos/stable/release-notes

Example of migrating Snapper configuration attributes from the old format to the new one.

```nix
{
  services.snapper.configs.example = {
    subvolume = "/example";

```

--------------------------------

### Install Azure CLI with Extensions

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this snippet to install the Azure CLI with specific extensions, such as `aks-preview`. The configuration files are moved into the derivation by default to ensure immutability.

```nix
{
  environment.systemPackages = [ (azure-cli.withExtensions [ azure-cli.extensions.aks-preview ]) ];
}
```

--------------------------------

### Gauge Plugin Installation with Nix

Source: https://nixos.org/manual/nixos/stable/release-notes

Install Gauge plugins directly using Nix. For imperative installation, use `gauge-unwrapped`.

```nix
gauge.fromManifest ./path/to/manifest.json
```

```nix
gauge.withPlugins (p: with p; [ js html-report xml-report ])
```

--------------------------------

### Install nixos-rebuild-ng alongside nixos-rebuild

Source: https://nixos.org/manual/nixos/stable/release-notes

Install `nixos-rebuild-ng` as a separate package by adding it to `environment.systemPackages`. It will be available as `nixos-rebuild-ng`.

```nix
environment.systemPackages = [ pkgs.nixos-rebuild-ng ];
```

--------------------------------

### Configure Nextcloud Package

Source: https://nixos.org/manual/nixos/stable/release-notes

Explicitly set the Nextcloud package to be installed. This is the recommended approach.

```nix
services.nextcloud.package = pkgs.nextcloud33;
```

--------------------------------

### Enable LXQt Desktop Environment with Qt 6 and Wayland Support

Source: https://nixos.org/manual/nixos/stable/release-notes

Install LXQt 2.0, which is based on Qt 6 and offers Wayland support for many applications.

```nix
services.desktopManager.lxqt.enable = true;
```

--------------------------------

### Configure MATE Extra Panel Applets

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this option to install panel applets for the MATE desktop environment, especially for those built with Wayland support.

```nix
services.xserver.desktopManager.mate.extraPanelApplets
```

--------------------------------

### Build Caddy with Plugins

Source: https://nixos.org/manual/nixos/stable/release-notes

Use `caddy.withPlugins` to build Caddy with custom plugins. Omit the `hash` argument to get the correct value if the build fails. Ensure all plugins have versions or tags.

```nix
let
  pkgs = import <nixpkgs> { };

in
pkgs.caddy.withPlugins {
  plugins = [
    # tagged upstream
    "github.com/caddy-dns/powerdns@v1.0.1"
    # pseudo-version number generated by Go
    "github.com/caddy-dns/cloudflare@v0.0.0-20240703190432-89f16b99c18e"
    "github.com/mholt/caddy-webdav@v0.0.0-20241008162340-42168ba04c9d"
  ];
  hash = "sha256-wqXSd1Ep9TVpQi570TTb96LwzNYvWL5EBJXMJfYWCAk=";
}

```

--------------------------------

### Install GNOME Session Path Extensions

Source: https://nixos.org/manual/nixos/stable/release-notes

Install the `gnome-shell-extensions` collection, which includes GNOME Classic extensions, Apps Menu, and User Themes, by setting `services.xserver.desktopManager.gnome.sessionPath`. These were not installed by default in this release.

```nix
services.xserver.desktopManager.gnome.sessionPath
```

--------------------------------

### Enable Plasma 6 Desktop Environment

Source: https://nixos.org/manual/nixos/stable/release-notes

Install Plasma 6, which runs as Wayland by default. The X11 session can be explicitly selected if needed. Plasma 5 is expected to be deprecated in the next release.

```nix
services.desktopManager.plasma6.enable = true;
```

--------------------------------

### Migrate Signald Database

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this command to migrate the Signald database before starting the Signald service. Ensure the paths are correct for your installation.

```bash
signald -d /var/lib/signald/db \
  --database sqlite:/var/lib/signald/db \
  --migrate-data

```

--------------------------------

### Configure sudo-rs with Extra Rules

Source: https://nixos.org/manual/nixos/stable/release-notes

When using the sudo-rs module, previously set rules are not automatically used. This example shows how to migrate existing sudo rules to sudo-rs.

```nix
security.sudo-rs.extraRules = security.sudo.extraRules;

```

--------------------------------

### Enable Lomiri Desktop Manager in NixOS

Source: https://nixos.org/manual/nixos/stable/release-notes

Install the Lomiri desktop environment, which uses Mir 2.x as a Wayland compositor. Note that some core applications and services may still be incomplete.

```nix
services.desktopManager.lomiri.enable = true;
```

--------------------------------

### Configure MATE Extra Caja Extensions

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this option to install Caja extensions for the MATE desktop environment.

```nix
services.xserver.desktopManager.mate.extraCajaExtensions
```

--------------------------------

### SSHFS Mount with Unsupported Option

Source: https://nixos.org/manual/nixos/stable/release-notes

Demonstrates an example of using `sshfs` with an unsupported mount option (`atime`). Previously, this would succeed silently; now, it results in an error and non-zero exit status due to stricter validation in `fuse3`.

```bash
$ sshfs 127.0.0.1:/home/test/testdir /home/test/sshfs_mnt -o atime
```

--------------------------------

### Stargazer Hardening and CGI Support

Source: https://nixos.org/manual/nixos/stable/release-notes

The `services.stargazer` service has been hardened for security. The new `services.stargazer.allowCgiUser` option enables traditional CGI setups.

```nix
services.stargazer.allowCgiUser
```

--------------------------------

### Configure GitHub Runner Service Overrides

Source: https://nixos.org/manual/nixos/stable/release-notes

Example of how to override systemd service configuration for GitHub runners using the `serviceOverrides` option. This is necessary if you were previously overriding `systemd.services.github-runner.serviceConfig`.

```nix
{ services.github-runner.serviceOverrides.SupplementaryGroups = [ "docker" ]; }

```

--------------------------------

### Configure Random Encryption for Swap Devices

Source: https://nixos.org/manual/nixos/stable/release-notes

Control sector size, cipher, and key size for NixOS swap partitions with random encryption. This allows for more granular control over the encryption setup compared to default cryptsetup behavior.

```nix
{ 
  swapDevices = [ 
    { 
      device = "/dev/disk/by-partlabel/swapspace";
      randomEncryption = { 
        enable = true;
        cipher = "aes-xts-plain64";
        keySize = 512;
        sectorSize = 4096;
      };
    }
  ];
}

```

--------------------------------

### Ensure Network Connectivity for System Services

Source: https://nixos.org/manual/nixos/stable/release-notes

System services that require network connectivity to start correctly must now explicitly declare their dependency on 'network-online.target'. This change prevents unnecessary delays in user logins.

```nix
{
  systemd.services.<name> = {
    wants = [ "network-online.target" ];
    after = [ "network-online.target" ];
  };
}
```

--------------------------------

### Disable Deferred Native Compilation in Emacs

Source: https://nixos.org/manual/nixos/stable/release-notes

If you do not want asynchronous deferred native compilation for Emacs packages installed outside of Nixpkgs, use `(setq native-comp-deferred-compilation nil)`.

```emacs-lisp
(setq native-comp-deferred-compilation nil)
```

--------------------------------

### Using system.nix as an Alternative Entry Point

Source: https://nixos.org/manual/nixos/stable/release-notes

This snippet demonstrates how to use `system.nix` as an alternative entry point to NixOS configuration without relying on `nix-channel`. It shows how to fetch a specific Nixpkgs archive and import it for building NixOS.

```nix
let
  # Pinned Nixpkgs archive
  #
  # Use `curl -I https://channels.nixos.org/nixos-26.05` to get the
  # latest commit of the stable channel and `nix --extra-experimental-features nix-command store prefetch-file --unpack`
  # to compute its hash.
  nixpkgs = builtins.fetchTarball {
    url = "https://github.com/NixOS/nixpkgs/archive/c217913993d6.tar.gz";
    hash = "sha256-D1PA3xQv/s4W3lnR9yJFSld8UOLr0a/cBWMQMXS+1Qg=";
  };
in
import "${nixpkgs}/nixos" {
  # Build NixOS using an external configuration.nix file,
  # or directly set your options here
  configuration = ./configuration.nix;
}

```

--------------------------------

### Import Linode Cloud Image Module

Source: https://nixos.org/manual/nixos/stable/release-notes

To support Linode cloud images, import `${modulesPath}/virtualisation/linode-image.nix` and access `system.build.linodeImage`.

```nix
${modulesPath}/virtualisation/linode-image.nix
```

```nix
system.build.linodeImage
```

--------------------------------

### Enable COSMIC DE Greeter

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable the COSMIC DE greeter by setting `services.displayManager.cosmic-greeter.enable`. This is part of the experimental support for COSMIC DE.

```nix
services.displayManager.cosmic-greeter.enable
```

--------------------------------

### Enable Saleae Logic Hardware Support

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable hardware support for the Saleae Logic device family using `hardware.saleae-logic.enable` and specify the package with `hardware.saleae-logic.package`.

```nix
hardware.saleae-logic.enable
```

```nix
hardware.saleae-logic.package
```

--------------------------------

### Configure Media Key Bindings with actkbd

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this snippet to configure media key bindings for volume control and mute using the `actkbd` service. Ensure `alsa-utils` is available in your environment.

```nix
{
  services.actkbd =
    let
      volumeStep = "1%";
    in
    {
      enable = true;
      bindings = [
        # "Mute" media key
        {
          keys = [ 113 ];
          events = [ "key" ];
          command = "${alsa-utils}/bin/amixer -q set Master toggle";
        }

        # "Lower Volume" media key
        {
          keys = [ 114 ];
          events = [
            "key"
            "rep"
          ];
          command = "${alsa-utils}/bin/amixer -q set Master ${volumeStep}- unmute";
        }

        # "Raise Volume" media key
        {
          keys = [ 115 ];
          events = [
            "key"
            "rep"
          ];
          command = "${alsa-utils}/bin/amixer -q set Master ${volumeStep}+ unmute";
        }

        # "Mic Mute" media key
        {
          keys = [ 190 ];
          events = [ "key" ];
          command = "${alsa-utils}/bin/amixer -q set Capture toggle";
        }
      ];
    };
}

```

--------------------------------

### Configure Single GitHub Runner

Source: https://nixos.org/manual/nixos/stable/release-notes

Options under `services.github-runner` remain available for configuring a single GitHub runner.

```nix
services.github-runner
```

--------------------------------

### Copying Over Module Definitions

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this snippet to move definitions for properties, modules, objects, SPA libraries, commands, rules, or PulseAudio commands into a drop-in configuration.

```json
{
  "context.properties": {
    "your.property.name": "your.property.value"
  },
  "context.modules": [
    { "name": "libpipewire-module-my-cool-thing" }
  ],
  "context.objects": [
    { "factory": { ... } }
  ],
  "alsa.rules": [
    { "matches: { ... }, "actions": { ... } }
  ]
}
```

--------------------------------

### Enable nixos-rebuild-ng

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable the new `nixos-rebuild-ng` tool by setting `system.rebuild.enableNg`. This will replace the old `nixos-rebuild`.

```nix
system.rebuild.enableNg
```

--------------------------------

### Enable JIT Compilation for PostgreSQL

Source: https://nixos.org/manual/nixos/stable/release-notes

Opt-in support for Just-In-Time (JIT) compilation in PostgreSQL. Enable this option to potentially improve query performance.

```nix
{ services.postgresql.enableJIT = true; }

```

--------------------------------

### Enable MATE Wayland Session

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable the Wayland session for the MATE desktop environment. This is an opt-in feature that requires Wayfire closures and suggests using SDDM as the display manager due to known issues with LightDM.

```nix
services.xserver.desktopManager.mate.enableWaylandSession = true;
```

--------------------------------

### Enable COSMIC DE

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable the COSMIC DE itself by setting `services.desktopManager.cosmic.enable`. This support is stable but considered experimental.

```nix
services.desktopManager.cosmic.enable
```

--------------------------------

### Configure User Passwords with yescrypt Hash

Source: https://nixos.org/manual/nixos/stable/release-notes

When using `users.users.<name>.hashedPassword` to configure user passwords, run `mkpasswd` and use the provided yescrypt hash.

```nix
users.users.<name>.hashedPassword
```

--------------------------------

### Using minio_legacy_fs for Data Migration

Source: https://nixos.org/manual/nixos/stable/release-notes

To migrate Minio storage from the legacy filesystem backend, use the `minio_legacy_fs` package to export data before switching to the new version.

```nix
services.minio.package = minio_legacy_fs;

```

--------------------------------

### Configuring Nextcloud Upgrade Path

Source: https://nixos.org/manual/nixos/stable/release-notes

To upgrade Nextcloud, declare `services.nextcloud.package = pkgs.nextcloud28;` to first upgrade to an intermediate version before moving to v29. Direct upgrades between major versions are not supported.

```nix
services.nextcloud.package = pkgs.nextcloud28;
```

--------------------------------

### Julia Environment Package Addition

Source: https://nixos.org/manual/nixos/stable/release-notes

Use the `.withPackages` function to build Julia environments with arbitrary ecosystem packages.

```nix
julia.withPackages ["Plots"]
```

--------------------------------

### Configure Asusd with Text Configuration

Source: https://nixos.org/manual/nixos/stable/release-notes

When upgrading asusd to version 6, existing configurations need to be updated to use the `text` attribute for specifying configuration file contents.

```nix
-services.asusd.asusdConfig = '''file contents'''
+services.asusd.asusdConfig.text = '''file contents'''
```

--------------------------------

### Configure CoreDNS with External Plugins

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable CoreDNS and override its package to include external plugins. This requires specifying the plugin's name, repository, version, and a vendor hash.

```nix
{
  services.coredns = {
    enable = true;
    package = pkgs.coredns.override {
      externalPlugins = [
        {
          name = "fanout";
          repo = "github.com/networkservicemesh/fanout";
          version = "v1.9.1";
        }
      ];
      vendorHash = "<SRI hash>";
    };
  };
}

```

--------------------------------

### Override indi-full for Non-Free Drivers

Source: https://nixos.org/manual/nixos/stable/release-notes

Demonstrates how to create a custom collection of INDI drivers by overriding the `indi-full` package to include non-free drivers. This is an alternative to using the `indi-full-nonfree` package.

```nix
pkgs.indi-with-drivers.override {extraDrivers = with pkgs.indi-3rdparty; [indi-gphoto];}
```

--------------------------------

### Enable Automatic Root Device Formatting in Systemd Initrd

Source: https://nixos.org/manual/nixos/stable/release-notes

To automatically format the root device when using the systemd initrd, set `virtualisation.fileSystems."/".autoFormat = true;`. This is a workaround for changes in the `qemu-vm.nix` module.

```nix
virtualisation.fileSystems."/".autoFormat = true;
```

--------------------------------

### Import Test Utility for Auto-Formatting Root Device

Source: https://nixos.org/manual/nixos/stable/release-notes

For NixOS tests that relied on the removed functionality of automatically formatting the root device in the initrd, import the test utility `nixos/tests/common/auto-format-root-device.nix`.

```nix
imports = [ ./common/auto-format-root-device.nix ];
```

--------------------------------

### Configure Declarative Trusted Substitute Servers for Guix

Source: https://nixos.org/manual/nixos/stable/release-notes

Declaratively manages trusted substitute servers for Guix. Instead of using `guix archive --authorize`, list authorized keys and default substitute server URLs.

```nix
services.guix.substituters.authorizedKeys
```

```nix
services.guix.substituters.urls
```

--------------------------------

### Configure Cross-Compilation Build Platform

Source: https://nixos.org/manual/nixos/stable/release-notes

To cross compile, set `nixpkgs.buildPlatform` to a different value than `nixpkgs.hostPlatform`. These options cover and override `nixpkgs.{system,localSystem,crossSystem}`.

```nix
nixpkgs.hostPlatform
```

```nix
nixpkgs.buildPlatform
```

--------------------------------

### Configure Portunus with Legacy libxcrypt

Source: https://nixos.org/manual/nixos/stable/release-notes

If upgrading to NixOS 24.05 without completing the Portunus user migration to strong password hashes, use this configuration to maintain support for weak password hashes. This involves overriding the package to use `libxcrypt-legacy`.

```nix
{
  services.portunus.package = pkgs.portunus.override { libxcrypt = pkgs.libxcrypt-legacy; };
  services.portunus.ldap.package = pkgs.openldap.override { libxcrypt = pkgs.libxcrypt-legacy; };
}
```

--------------------------------

### Configure Qt Adwaita Style

Source: https://nixos.org/manual/nixos/stable/release-notes

If you still want Adwaita style for Qt applications, you can add these options to your configuration. Be aware that this may be removed in the future.

```nix
{
  qt = {
    enable = true;
    platformTheme = "gnome";
    style = "adwaita";
  };
}

```

--------------------------------

### Configure Multiple GitHub Runners

Source: https://nixos.org/manual/nixos/stable/release-notes

Use `services.github-runners.<name>` to configure multiple GitHub runners. The options under `services.github-runner` are for configuring a single runner.

```nix
services.github-runners.<name>
```

--------------------------------

### Build Platform-Specific Images

Source: https://nixos.org/manual/nixos/stable/release-notes

Use the `nixos-rebuild build-image` sub-command to build platform-specific disk images from NixOS configurations. This functionality is also available for `nixos-rebuild-ng`.

```bash
nixos-rebuild build-image
```

--------------------------------

### Migrate from LSH to OpenSSH

Source: https://nixos.org/manual/nixos/stable/release-notes

Recommends migrating from the removed `lsh` and `services.lshd` packages to `openssh` and `services.openssh`. This is due to lack of maintenance and upstream releases for `lsh`.

```nix
services.openssh
```

--------------------------------

### FetchNextcloudApp Rewrite

Source: https://nixos.org/manual/nixos/stable/release-notes

The `fetchNextcloudApp` function was rewritten to use `fetchurl` instead of `fetchzip`. Existing hashes are invalidated. To restore old behavior, pass `unpack = true`.

```nix
fetchNextcloudApp
```

--------------------------------

### Configure Kanidm Unix Module with SSH Integration

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable SSH key integration for the Kanidm Unix module. This moves options under dedicated namespaces.

```nix
services.kanidm.unix.sshIntegration = true;
```

--------------------------------

### Accessing Option Declaration Positions

Source: https://nixos.org/manual/nixos/stable/release-notes

Demonstrates how to access the declaration positions of an option in Nixpkgs. This shows the file and line number where an option was declared.

```nix
$ nix-repl -f '<nixpkgs/nixos>' [..]
nix-repl> :p options.environment.systemPackages.declarationPositions
[ {
  column = 7;
  file = "/nix/store/vm9zf9wvfd628cchj0hdij1g4hzjrcz9-source/nixos/modules/config/system-path.nix";
  line = 62;
} ]

```

--------------------------------

### SSH into VMs via AF_VSOCK

Source: https://nixos.org/manual/nixos/stable/release-notes

Connect to virtual machines using SSH over AF_VSOCK. Requires hypervisor support and an SSH key for the root user.

```bash
ssh root@.host

```

--------------------------------

### Configure MySQL Galera Cluster

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable and configure a MySQL Galera Cluster with specified node details. Ensure services.mysql.enable is also set to true.

```nix
{
  services.mysql = {
    enable = true;
    galeraCluster = {
      enable = true;
      localName = "Node 1";
      localAddress = "galera_01";
      nodeAddresses = [
        "galera_01"
        "galera_02"
        "galera_03"
      ];
    };
  };
}

```

--------------------------------

### GitLab Registry Configuration

Source: https://nixos.org/manual/nixos/stable/release-notes

This snippet demonstrates how to switch to GitLab's recommended container registry package (`pkgs.gitlab-container-registry`) when the external registry (`pkgs.docker-distribution`) is deprecated in GitLab 16.

```nix
services.gitlab.registry.package = pkgs.gitlab-container-registry;
```

--------------------------------

### Use Nixpkgs Tarball as Flake Input

Source: https://nixos.org/manual/nixos/stable/release-notes

Use the Nixpkgs tarball from channels.nixos.org as a Nix Flake input by specifying the URL. This allows for reproducible builds using specific channel archives.

```nix
inputs.nixpkgs.url = "https://channels.nixos.org/nixos-25.05/nixexprs.tar.xz";
```

--------------------------------

### Configure Prometheus Exporter for PGBouncer using Environment File

Source: https://nixos.org/manual/nixos/stable/release-notes

Replaces the removed `connectionStringFile` option for the Prometheus PGBouncer exporter. Use `connectionEnvFile` to specify a file containing environment variables for the connection, avoiding password exposure in process command lines.

```nix
services.prometheus.exporters.pgbouncer.connectionEnvFile
```

--------------------------------

### Configure InvoicePlane with Caddy for HTTP

Source: https://nixos.org/manual/nixos/stable/release-notes

Maintain the old behavior for an InvoicePlane site served by Caddy to use HTTP only, instead of Caddy's automatic HTTPS.

```nix
services.caddy.virtualHosts."example.com".hostName = "http://example.com";
```

--------------------------------

### Configure sudo-rs Module

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable the experimental sudo-rs module for a Rust reimplementation of sudo. Note that terminfo-related environment variables are not preserved for root and wheel, and they cannot set arbitrary environment variables.

```nix
security.sudo-rs.enable = true;

```

--------------------------------

### Enable GNOME Core Developer Tools

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable GNOME core developer tools, including `sysprof` and `d-spy`, by setting `services.gnome.core-developer-tools.enable`. This option provides access to system profiling and debugging tools.

```nix
services.gnome.core-developer-tools.enable
```

--------------------------------

### Replace Prisma Package

Source: https://nixos.org/manual/nixos/stable/release-notes

The `nodePackages.prisma` package has been replaced by `prisma`.

```nix
nodePackages.prisma
```

--------------------------------

### Enable NVIDIA Open-Source Driver

Source: https://nixos.org/manual/nixos/stable/release-notes

Use the new `hardware.nvidia.open` option to enable the usage of NVIDIA’s open-source kernel driver. Note that support for GeForce and Workstation GPUs is still in alpha.

```nix
hardware.nvidia.open
```

--------------------------------

### Enable nsncd Service

Source: https://nixos.org/manual/nixos/stable/release-notes

Help test the new `nsncd` implementation by setting `services.nscd.enableNsncd` to `true`. This service replaces `nscd` for resolving hostnames and users.

```nix
services.nscd.enableNsncd = true;
```

--------------------------------

### Enable Initrd Backdoor for NixOS Tests

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable the backdoor service in the initrd for NixOS tests. This requires boot.initrd.systemd to be enabled and allows commands to be sent to test and debug Stage 1.

```nix
testing.initrdBackdoor

```

--------------------------------

### Update systemd.coredump configuration

Source: https://nixos.org/manual/nixos/stable/release-notes

Replace the removed `systemd.coredump.extraConfig` option with the structured `systemd.coredump.settings.Coredump` for setting `coredump.conf(5)` options.

```nix
systemd.coredump.extraConfig = "Storage=journal";
```

```nix
systemd.coredump.settings.Coredump.Storage = "journal";
```

--------------------------------

### Manage Global Mesa Version

Source: https://nixos.org/manual/nixos/stable/release-notes

Manage the global Mesa version without a mass rebuild by setting `hardware.graphics.package`. This allows for more flexible graphics driver updates.

```nix
hardware.graphics.package
```

--------------------------------

### Configure Mattermost user limits and badges

Source: https://nixos.org/manual/nixos/stable/release-notes

Override the Mattermost package to disable user limits and free badges when upgrading to version 11, which defaults to Postgres and restricts users.

```nix
{
  services.mattermost.package = pkgs.mattermost.override {
    removeUserLimit = true;
    removeFreeBadge = true;
  };
}
```

--------------------------------

### Configuring NetBox Package Version

Source: https://nixos.org/manual/nixos/stable/release-notes

Specify the NetBox package version using `services.netbox.package`. Defaults to v3.6 if `stateVersion` is earlier than 24.05. Database migrations run automatically.

```nix
services.netbox.package = pkgs.netbox_3_7;
```

--------------------------------

### Shiori HTTP Secret Environment Variable

Source: https://nixos.org/manual/nixos/stable/release-notes

The `services.shiori` service now requires the `SHIORI_HTTP_SECRET_KEY` to be provided as an environment variable. Use `services.shiori.environmentFile` to manage this.

```nix
services.shiori.environmentFile
```

--------------------------------

### Migrate Caddy Options for InvoicePlane

Source: https://nixos.org/manual/nixos/stable/release-notes

Migrate custom Caddy options for an InvoicePlane site by removing the 'http://' prefix from the virtual host configuration.

```nix
services.caddy.virtualHosts."http://example.com"
```

--------------------------------

### Importing NixOS Modules via Environment Variable

Source: https://nixos.org/manual/nixos/stable/release-notes

This snippet shows how to import NixOS modules using the NIXOS_EXTRA_MODULE_PATH environment variable. This is a workaround for a deprecated feature, and updating expression files is recommended.

```nix
{
  imports = [
    (builtins.getEnv "NIXOS_EXTRA_MODULE_PATH")
  ];
}

```

--------------------------------

### Disable File System Overrides in QEMU VMs

Source: https://nixos.org/manual/nixos/stable/release-notes

Prevent the qemu-vm.nix module from overriding fileSystems, allowing VMs to boot from external disk images. This is achieved by setting virtualisation.fileSystems to an empty list using lib.mkForce.

```nix
virtualisation.fileSystems = lib.mkForce { };

```

--------------------------------

### Enable Perlless Profile in NixOS Configuration

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this profile to create a system without Perl. This is an opt-in mechanism to replace Perl scripts used during NixOS activation.

```nix
{ modulesPath, ... }:
{
  imports = [ "${modulesPath}/profiles/perlless.nix" ];
}

```

--------------------------------

### Stalwart Mail System User Change

Source: https://nixos.org/manual/nixos/stable/release-notes

The `services.stalwart-mail` service now runs under the `stalwart-mail` system user instead of a dynamic one. This requires manually moving the state directory and updating its ownership.

```nix
services.stalwart-mail
```

--------------------------------

### Restoring kbrequest.target to rescue.target Symlink

Source: https://nixos.org/manual/nixos/stable/release-notes

This configuration snippet restores the previous behavior where the systemd target `kbrequest.target` was symlinked to `rescue.target`. This is useful if your workflow relies on the Alt+ArrowUp shortcut to change the current target to `rescue.target`.

```nix
systemd.targets.rescue.aliases = [ "kbrequest.target" ];
```

--------------------------------

### Rename GNOME Core Utilities Option

Source: https://nixos.org/manual/nixos/stable/release-notes

The option `services.gnome.core-utilities.enable` has been renamed to `services.gnome.core-apps.enable`. This change reflects the functionality of the option more accurately.

```nix
services.gnome.core-apps.enable
```

--------------------------------

### Customizing Fcitx5 RIME Data

Source: https://nixos.org/manual/nixos/stable/release-notes

This snippet demonstrates how to customize RIME data packages for Fcitx5 when the default `i18n.inputMethod.fcitx5.enableRimeData` option is removed. Users can specify desired RIME data packages using `pkgs.rime-data` and other packages.

```nix
fcitx5-rime.override {
  rimeDataPkgs = [
    pkgs.rime-data
    # ...
  ];
}
```

--------------------------------

### Teleport Upgrade to Version 11

Source: https://nixos.org/manual/nixos/stable/release-notes

This snippet shows how to upgrade Teleport to an intermediate version 11.x by explicitly setting the package. This is recommended when upgrading across major versions (e.g., from 10 to 12).

```nix
services.teleport.package = pkgs.teleport_11;
```

--------------------------------

### Override PHP Options in Nextcloud

Source: https://nixos.org/manual/nixos/stable/release-notes

Use `lib.mkForce` to override all default PHP options for Nextcloud, including upload size and memory limits. This is useful when specific configurations are required that differ from the system defaults.

```nix
{ services.nextcloud.phpOptions = lib.mkForce {
    # ...
  };
}
```

--------------------------------

### Securely Pass WPA Supplicant Secrets

Source: https://nixos.org/manual/nixos/stable/release-notes

Pass secrets like Pre-Shared Keys for wpa_supplicant safely using networking.wireless.environmentFile. This prevents non-root users from reading the configuration file.

```nix
networking.wireless.environmentFile

```

--------------------------------

### Upgrade Nextcloud Version

Source: https://nixos.org/manual/nixos/stable/release-notes

Upgrade from an older Nextcloud version to a newer one by specifying the intermediate package. Direct upgrades across major versions are not supported.

```nix
services.nextcloud.package = pkgs.nextcloud32;
```

--------------------------------

### Restore Default inetutils Priority

Source: https://nixos.org/manual/nixos/stable/release-notes

If `inetutils` has a lower priority and shadows `util-linux`, you can restore its default priority using this Nix expression.

```nix
lib.setPrio 5 inetutils
```

```nix
meta.priority = 5
```

--------------------------------

### Set Shiori HTTP Secret Key

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this snippet to set the Shiori HTTP secret key by generating a random hex string and saving it to an environment file. Ensure the environment file path is correctly configured in services.shiori.environmentFile.

```shell
# $ printf "SHIORI_HTTP_SECRET_KEY=%s\n" "$(openssl rand -hex 16)" > /path/to/env-file
services.shiori.environmentFile = "/path/to/env-file";
```

--------------------------------

### Refactored FRR Configuration

Source: https://nixos.org/manual/nixos/stable/release-notes

Illustrates the refactored configuration for `services.frr` using upstream service scripts. Per-daemon configurations are replaced by an integrated `vtysh-config` style, and daemon submodules now use daemon names instead of protocol names.

```nix
options
```

```nix
extraOptions
```

--------------------------------

### Build Shared Library Without Executable Stack

Source: https://nixos.org/manual/nixos/stable/release-notes

When building a shared library from source, use these linker flags to prevent the stack from being executable.

```nix
mkDerivation {
  # …

  env.NIX_LDFLAGS = "-z,noexecstack";
}
```

--------------------------------

### Haskell Packaging Helper Change

Source: https://nixos.org/manual/nixos/stable/release-notes

The `haskell.lib.compose.justStaticExecutables` helper now disallows GHC references by default to address closure size issues. Refer to the Haskell section of the Nixpkgs manual for workarounds.

```nix
haskell.lib.compose.justStaticExecutables
```

--------------------------------

### Configure Nginx HTTP/3 Alt-Svc Header

Source: https://nixos.org/manual/nixos/stable/release-notes

Manually add HTTP/3 availability to Nginx locations using the Alt-Svc header. This is required for Nginx to advertise HTTP/3 support.

```nix
{
  locations."/".extraConfig = ''
    add_header Alt-Svc 'h3=":$server_port"; ma=86400';
  '';
  locations."^~ /assets/".extraConfig = ''
    add_header Alt-Svc 'h3=":$server_port"; ma=86400';
  '';
}

```

--------------------------------

### Update VSCode Language Server Packages

Source: https://nixos.org/manual/nixos/stable/release-notes

Replace deprecated VSCode language server packages with the maintained `vscode-langservers-extracted` package.

```nix
nodePackages.vscode-css-languageserver-bin
nodePackages.vscode-html-languageserver-bin
nodePackages.vscode-json-languageserver-bin
```

--------------------------------

### Kubernetes Feature Gates: List to Attribute Set

Source: https://nixos.org/manual/nixos/stable/release-notes

Configuration for Kubernetes feature gates has changed from a list of strings to an attribute set. This allows for enabling and disabling feature gates more granularly.

```nix
{
  featureGates = [ "EphemeralContainers" ];
  extraOpts = pkgs.lib.concatStringsSep " " ([ ''--feature-gates="CSIMigration=false"'' ]);
}
```

```nix
{
  featureGates = {
    EphemeralContainers = true;
    CSIMigration = false;
  };
}
```

--------------------------------

### Configure ZFS Hibernation Behavior

Source: https://nixos.org/manual/nixos/stable/release-notes

Control ZFS hibernation behavior using the `boot.zfs.allowHibernation` option. By default, hibernation is disabled to prevent data loss.

```nix
boot.zfs.allowHibernation
```

--------------------------------

### Configure DHCPCD for IPv6 Router Advertisements

Source: https://nixos.org/manual/nixos/stable/release-notes

Enable DHCPCD to solicit or accept IPv6 Router Advertisements on interfaces using static IPv6 addresses. This is necessary if your network provides both ULA and GUA through SLAAC.

```nix
networking.dhcpcd.IPv6rs = true;

```

--------------------------------

### Force Executable Stack for Shared Library

Source: https://nixos.org/manual/nixos/stable/release-notes

If a shared library requires an executable stack and it's not enabled by the application, force this behavior using `GLIBC_TUNABLES`. This reduces security and should not be set globally.

```bash
GLIBC_TUNABLES=glibc.rtld.execstack=2
```

--------------------------------

### Update BorgBackup Extra Arguments to Bash Arrays

Source: https://nixos.org/manual/nixos/stable/release-notes

The values for `services.borgbackup.jobs.*.extraArgs` and similar options are now Bash arrays. Existing preHook modifications need to be adjusted to append to these arrays.

```bash
-extraCreateArgs="$extraCreateArgs --exclude /some/path"
+extraCreateArgs+=("--exclude" "/some/path")
```

--------------------------------

### Configure Mastodon Media Auto-Removal

Source: https://nixos.org/manual/nixos/stable/release-notes

Configure the automatic removal of remote media attachments older than 30 days in Mastodon using `services.mastodon.mediaAutoRemove`.

```nix
services.mastodon.mediaAutoRemove
```

--------------------------------

### Configure CPU Model-Specific Registers (MSR)

Source: https://nixos.org/manual/nixos/stable/release-notes

Configure the msr kernel module to provide an interface for reading and writing model-specific registers (MSRs) of an x86 CPU.

```nix
hardware.cpu.x86.msr

```

--------------------------------

### Disable Firewall Logging of Refused Connections

Source: https://nixos.org/manual/nixos/stable/release-notes

The `networking.firewall.logRefusedConnections` option now defaults to `false`. Setting it to `true` can generate excessive log messages.

```nix
networking.firewall.logRefusedConnections = false;
```

--------------------------------

### Override Dwarf Fortress Version

Source: https://nixos.org/manual/nixos/stable/release-notes

Use this override to run an earlier version of Dwarf Fortress if needed. This is useful for compatibility with older save files.

```nix
dwarf-fortress-packages.dwarf-fortress-full.override { dfVersion = "0.47.5"; }
```

--------------------------------

### Disable Automatic Nix Path and Registry Configuration for Flakes

Source: https://nixos.org/manual/nixos/stable/release-notes

Set these options to false to prevent NixOS from automatically setting `NIX_PATH` and the system-wide flake registry when using flake-based configurations. This is recommended for closure-size-constrained non-interactive systems.

```nix
nixpkgs.flake.setNixPath = false;
nixpkgs.flake.setFlakeRegistry = false;
```

--------------------------------

### Override Django Package

Source: https://nixos.org/manual/nixos/stable/release-notes

This snippet shows how to override the default Django package to use a specific version (django_3). This is useful for managing dependencies in Nix.

```nix
packageOverrides = self: super: {
  django = super.django_3;
};

```

--------------------------------

### Overriding rt_tables Configuration

Source: https://nixos.org/manual/nixos/stable/release-notes

Setting `environment.etc."iproute2/rt_tables".text` overrides the entire configuration file. This applies to other `CONFIG_FILE_NAME` values as well.

```nix
environment.etc."iproute2/rt_tables".text = ''
  127.0.0.1       localhost
  255.255.255.255 broadcasthost
'';
```

--------------------------------

### Re-adding MACs to OpenSSH Configuration

Source: https://nixos.org/manual/nixos/stable/release-notes

If you require MAC-then-encrypt algorithms for compatibility with libraries like libssh2 or older iPhone SSH clients, you can re-add them to the OpenSSH server configuration.

```nix
{
  services.openssh.settings.Macs = [
    "hmac-sha2-512"
    "hmac-sha2-256"
    "umac-128@openssh.com"
  ];
}

```

--------------------------------

### Restore Old Coredns Behavior in Kubernetes

Source: https://nixos.org/manual/nixos/stable/release-notes

If you want to revert to the old behavior of pulling the upstream container image from Docker Hub for `services.kubernetes.addons.dns.coredns`, configure `services.kubernetes.addons.dns.corednsImage` as shown. This uses `pkgs.dockerTools.pullImage` to fetch the specified image.

```nix
{
  services.kubernetes.addons.dns.corednsImage = pkgs.dockerTools.pullImage {
    imageName = "coredns/coredns";
    imageDigest = "sha256:af8c8d35a5d184b386c4a6d1a012c8b218d40d1376474c7d071bb6c07201f47d";
    finalImageTag = "v1.12.2";
    hash = "sha256-ZgXEyxVrdskQdgg0ONJ9sboAXEEHTgNsiptk5O945c0=";
  };
}

```

--------------------------------

### Modifying Module Parameters

Source: https://nixos.org/manual/nixos/stable/release-notes

Reload a module with new arguments to modify its parameters. This is common for modules like libpipewire-module-rt.

```json
{
  "context.modules": [
    {
      "name": "libpipewire-module-rt",
      "args": {
        "rt.prio": 90
      }
    }
  ]
}
```

--------------------------------

### Opt-in to Widevine DRM in Chromium

Source: https://nixos.org/manual/nixos/stable/release-notes

To enable Widevine DRM support in Chromium, explicitly opt-in using `enableWidevine = true`. This is required because Chromium no longer automatically downloads Widevine.

```nix
chromium.override { enableWidevine = true; }
```

--------------------------------

### Disable Default Music Player

Source: https://nixos.org/manual/nixos/stable/release-notes

Disable the default `decibels` music player by using `environment.gnome.excludePackages`. This option allows customization of default GNOME applications.

```nix
environment.gnome.excludePackages
```

--------------------------------

### Generate HTTP Secret Key

Source: https://nixos.org/manual/nixos/stable/release-notes

Generates a random hexadecimal string for use as an HTTP secret key and outputs it to a file. This is useful for configuring applications that require a secret key for HTTP communication.

```bash
printf "SHIORI_HTTP_SECRET_KEY=%s\n" "$(openssl rand -hex 16)" > /path/to/env-file
```

--------------------------------

### Clear Execstack Flag from Binary-Only Shared Library

Source: https://nixos.org/manual/nixos/stable/release-notes

If the source code for a shared library is unavailable, use `patchelf` to remove the executable stack flag.

```bash
patchelf --clear-execstack binary-only.so
```

--------------------------------

### Disable NixOS Stub ELF Loader

Source: https://nixos.org/manual/nixos/stable/release-notes

This option disables the stub ELF loader that displays an error message for non-NixOS binaries. It is automatically disabled if `programs.nix-ld.enable` is used.

```nix
environment.stub-ld.enable = false;
```

--------------------------------

### Disable Redis RDB Persistence

Source: https://nixos.org/manual/nixos/stable/release-notes

The Redis module now disables RDB persistence when `services.redis.servers.<name>.save = []`, overriding the Redis default behavior.

```nix
services.redis.servers.<name>.save = []
```

--------------------------------

### Disable nsncd NSS Lookup Dispatcher

Source: https://nixos.org/manual/nixos/stable/release-notes

If problems arise with the new nsncd NSS lookup dispatcher, you can revert to the previous behavior by disabling it using this configuration option.

```nix
{ services.nscd.enableNsncd = false; }
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.