Many new modules are now core modules, most notably `services.prosody.modules.carbons` and `services.prosody.modules.mam`.

  The better-performing `libevent` backend is now enabled by default.

  `withCommunityModules` now passes through the modules to `services.prosody.extraModules`. Use `withOnlyInstalledCommunityModules` for modules that should not be enabled directly, e.g `lib_ldap`.

- All prometheus exporter modules are now defined as submodules. The exporters are configured using `services.prometheus.exporters`.

## Other Notable Changes {#sec-release-18.03-notable-changes}

- ZNC option `services.znc.mutable` now defaults to `true`. That means that old configuration is not overwritten by default when update to the znc options are made.

- The option `networking.wireless.networks.<name>.auth` has been added for wireless networks with WPA-Enterprise authentication. There is also a new `extraConfig` option to directly configure `wpa_supplicant` and `hidden` to connect to hidden networks.

- In the module `networking.interfaces.<name>` the following options have been removed:

  - `ipAddress`

  - `ipv6Address`

  - `prefixLength`

  - `ipv6PrefixLength`

  - `subnetMask`

  To assign static addresses to an interface the options `ipv4.addresses` and `ipv6.addresses` should be used instead. The options `ip4` and `ip6` have been renamed to `ipv4.addresses` `ipv6.addresses` respectively. The new options `ipv4.routes` and `ipv6.routes` have been added to set up static routing.

- The option `services.logstash.listenAddress` is now `127.0.0.1` by default. Previously the default behaviour was to listen on all interfaces.

- `services.btrfs.autoScrub` has been added, to periodically check btrfs filesystems for data corruption. If there's a correct copy available, it will automatically repair corrupted blocks.

- `displayManager.lightdm.greeters.gtk.clock-format.` has been added, the clock format string (as expected by strftime, e.g. `%H:%M`) to use with the lightdm gtk greeter panel.

  If set to null the default clock format is used.

- `displayManager.lightdm.greeters.gtk.indicators` has been added, a list of allowed indicator modules to use with the lightdm gtk greeter panel.

  Built-in indicators include `~a11y`, `~language`, `~session`, `~power`, `~clock`, `~host`, `~spacer`. Unity indicators can be represented by short name (e.g. `sound`, `power`), service file name, or absolute path.

  If set to `null` the default indicators are used.

  In order to have the previous default configuration add

  ```nix
  {
    services.xserver.displayManager.lightdm.greeters.gtk.indicators = [
      "~host" "~spacer"
      "~clock" "~spacer"
      "~session"
      "~language"
      "~a11y"
      "~power"
    ];
  }
  ```

  to your `configuration.nix`.

- The NixOS test driver supports user services declared by `systemd.user.services`. The methods `waitForUnit`, `getUnitInfo`, `startJob` and `stopJob` provide an optional `$user` argument for that purpose.

- Enabling bash completion on NixOS, `programs.bash.enableCompletion`, will now also enable completion for the Nix command line tools by installing the [nix-bash-completions](https://github.com/hedning/nix-bash-completions) package.

- The vim/kakoune plugin updater now reads from a CSV file: check `pkgs/applications/editors/vim/plugins/vim-plugin-names` out to see the new format