<section xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="sec-release-18.09">
  <title>Release 18.09 (<quote>Jellyfish</quote>, 2018/10/05)</title>
  <section xml:id="sec-release-18.09-highlights">
    <title>Highlights</title>
    <para>
      In addition to numerous new and upgraded packages, this release
      has the following notable updates:
    </para>
    <itemizedlist>
      <listitem>
        <para>
          End of support is planned for end of April 2019, handing over
          to 19.03.
        </para>
      </listitem>
      <listitem>
        <para>
          Platform support: x86_64-linux and x86_64-darwin as always.
          Support for aarch64-linux is as with the previous releases,
          not equivalent to the x86-64-linux release, but with efforts
          to reach parity.
        </para>
      </listitem>
      <listitem>
        <para>
          Nix has been updated to 2.1; see its
          <link xlink:href="https://nixos.org/nix/manual/#ssec-relnotes-2.1">release
          notes</link>.
        </para>
      </listitem>
      <listitem>
        <para>
          Core versions: linux: 4.14 LTS (unchanged), glibc: 2.26 →
          2.27, gcc: 7 (unchanged), systemd: 237 → 239.
        </para>
      </listitem>
      <listitem>
        <para>
          Desktop version changes: gnome: 3.26 → 3.28, (KDE)
          plasma-desktop: 5.12 → 5.13.
        </para>
      </listitem>
    </itemizedlist>
    <para>
      Notable changes and additions for 18.09 include:
    </para>
    <itemizedlist>
      <listitem>
        <para>
          Support for wrapping binaries using
          <literal>firejail</literal> has been added through
          <literal>programs.firejail.wrappedBinaries</literal>.
        </para>
        <para>
          For example
        </para>
        <programlisting language="bash">
{
  programs.firejail = {
    enable = true;
    wrappedBinaries = {
      firefox = &quot;${lib.getBin pkgs.firefox}/bin/firefox&quot;;
      mpv = &quot;${lib.getBin pkgs.mpv}/bin/mpv&quot;;
    };
  };
}
</programlisting>
        <para>
          This will place <literal>firefox</literal> and
          <literal>mpv</literal> binaries in the global path wrapped by
          firejail.
        </para>
      </listitem>
      <listitem>
        <para>
          User channels are now in the default
          <literal>NIX_PATH</literal>, allowing users to use their
          personal <literal>nix-channel</literal> defined channels in
          <literal>nix-build</literal> and <literal>nix-shell</literal>
          commands, as well as in imports like
          <literal>import &lt;mychannel&gt;</literal>.
        </para>
        <para>
          For example
        </para>
        <programlisting>
$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable nixpkgsunstable
$ nix-channel --update
$ nix-build '&lt;nixpkgsunstable&gt;' -A gitFull
$ nix run -f '&lt;nixpkgsunstable&gt;' gitFull
$ nix-instantiate -E '(import &lt;nixpkgsunstable&gt; {}).gitFull'
</programlisting>
      </listitem>
    </itemizedlist>
  </section>
  <section xml:id="sec-release-18.09-new-services">
    <title>New Services</title>
    <para>
      A curated selection of new services that were added since the last
      release:
    </para>
    <itemizedlist>
      <listitem>
        <para>
          The <literal>services.cassandra</literal> module has been
          reworked and was rewritten from scratch. The service has
          succeeding tests for the versions 2.1, 2.2, 3.0 and 3.11 of
          <link xlink:href="https://cassandra.apache.org/">Apache
          Cassandra</link>.
        </para>
      </listitem>
      <listitem>
        <para>
          There is a new <literal>services.foundationdb</literal> module
          for deploying
          <link xlink:href="https://www.foundationdb.org">FoundationDB</link>
          clusters.
        </para>
      </listitem>
      <listitem>
        <para>
          When enabled the <literal>iproute2</literal> will copy the
          files expected by ip route (e.g.,
          <literal>rt_tables</literal>) in
          <literal>/etc/iproute2</literal>. This allows to write aliases
          for routing tables for instance.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>services.strongswan-swanctl</literal> is a modern
          replacement for <literal>services.strongswan</literal>. You
          can use either one of them to setup IPsec VPNs but not both at
          the same time.
        </para>
        <para>
          <literal>services.strongswan-swanctl</literal> uses the
          <link xlink:href="https://wiki.strongswan.org/projects/strongswan/wiki/swanctl">swanctl</link>
          command which uses the modern
          <link xlink:href="https://github.com/strongswan/strongswan/blob/master/src/libcharon/plugins/vici/README.md">vici</link>
          <emphasis>Versatile IKE Configuration Interface</emphasis>.
          The deprecated <literal>ipsec</literal> command used in
          <literal>services.strongswan</literal> is using the legacy
          <link xlink:href="https://github.com/strongswan/strongswan/blob/master/README_LEGACY.md">stroke
          configuration interface</link>.
        </para>
      </listitem>
      <listitem>
        <para>
          The new <literal>services.elasticsearch-curator</literal>
          service periodically curates or manages, your Elasticsearch
          indices and snapshots.
        </para>
      </listitem>
    </itemizedlist>
    <para>
      Every new services:
    </para>
    <itemizedlist>
      <listitem>
        <para>
          <literal>./config/xdg/autostart.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./config/xdg/icons.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./config/xdg/menus.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./config/xdg/mime.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./hardware/brightnessctl.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./hardware/onlykey.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./hardware/video/uvcvideo/default.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./misc/documentation.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./programs/firejail.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./programs/iftop.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./programs/sedutil.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./programs/singularity.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./programs/xss-lock.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./programs/zsh/zsh-autosuggestions.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/admin/oxidized.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/backup/duplicati.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/backup/restic.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/backup/restic-rest-server.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/cluster/hadoop/default.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/databases/aerospike.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/databases/monetdb.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/desktops/bamf.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/desktops/flatpak.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/desktops/zeitgeist.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/development/bloop.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/development/jupyter/default.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/hardware/lcd.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/hardware/undervolt.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/misc/clipmenu.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/misc/gitweb.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/misc/serviio.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/misc/safeeyes.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/misc/sysprof.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/misc/weechat.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/monitoring/datadog-agent.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/monitoring/incron.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/dnsdist.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/freeradius.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/hans.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/morty.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/ndppd.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/ocserv.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/owamp.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/quagga.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/shadowsocks.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/stubby.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/networking/zeronet.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/security/certmgr.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/security/cfssl.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/security/oauth2_proxy_nginx.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/web-apps/virtlyst.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/web-apps/youtrack.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/web-servers/hitch/default.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/web-servers/hydron.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/web-servers/meguca.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./services/web-servers/nginx/gitweb.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./virtualisation/kvmgt.nix</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>./virtualisation/qemu-guest-agent.nix</literal>
        </para>
      </listitem>
    </itemizedlist>
  </section>
  <section xml:id="sec-release-18.09-incompatibilities">
    <title>Backward Incompatibilities</title>
    <para>
      When upgrading from a previous release, please be aware of the
      following incompatible changes:
    </para>
    <itemizedlist>
      <listitem>
        <para>
          Some licenses that were incorrectly not marked as unfree now
          are. This is the case for:
        </para>
        <itemizedlist>
          <listitem>
            <para>
              cc-by-nc-sa-20: Creative Commons Attribution Non
              Commercial Share Alike 2.0
            </para>
          </listitem>
          <listitem>
            <para>
              cc-by-nc-sa-25: Creative Commons Attribution Non
              Commercial Share Alike 2.5
            </para>
          </listitem>
          <listitem>
            <para>
              cc-by-nc-sa-30: Creative Commons Attribution Non
              Commercial Share Alike 3.0
            </para>
          </listitem>
          <listitem>
            <para>
              cc-by-nc-sa-40: Creative Commons Attribution Non
              Commercial Share Alike 4.0
            </para>
          </listitem>
          <listitem>
            <para>
              cc-by-nd-30: Creative Commons Attribution-No Derivative
              Works v3.00
            </para>
          </listitem>
          <listitem>
            <para>
              msrla: Microsoft Research License Agreement
            </para>
          </listitem>
        </itemizedlist>
      </listitem>
      <listitem>
        <para>
          The deprecated <literal>services.cassandra</literal> module
          has seen a complete rewrite. (See above.)
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.strict</literal> is removed. Use
          <literal>builtins.seq</literal> instead.
        </para>
      </listitem>
      <listitem>
        <para>
          The <literal>clementine</literal> package points now to the
          free derivation. <literal>clementineFree</literal> is removed
          now and <literal>clementineUnfree</literal> points to the
          package which is bundled with the unfree
          <literal>libspotify</literal> package.
        </para>
      </listitem>
      <listitem>
        <para>
          The <literal>netcat</literal> package is now taken directly
          from OpenBSD's <literal>libressl</literal>, instead of relying
          on Debian's fork. The new version should be very close to the
          old version, but there are some minor differences.
          Importantly, flags like -b, -q, -C, and -Z are no longer
          accepted by the nc command.
        </para>
      </listitem>
      <listitem>
        <para>
          The <literal>services.docker-registry.extraConfig</literal>
          object doesn't contain environment variables anymore. Instead
          it needs to provide an object structure that can be mapped
          onto the YAML configuration defined in
          <link xlink:href="https://github.com/docker/distribution/blob/v2.6.2/docs/configuration.md">the
          <literal>docker/distribution</literal> docs</link>.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>gnucash</literal> has changed from version 2.4 to
          3.x. If you've been using <literal>gnucash</literal> (version
          2.4) instead of <literal>gnucash26</literal> (version 2.6) you
          must open your Gnucash data file(s) with
          <literal>gnucash26</literal> and then save them to upgrade the
          file format. Then you may use your data file(s) with Gnucash
          3.x. See the upgrade
          <link xlink:href="https://wiki.gnucash.org/wiki/FAQ#Using_Different_Versions.2C_Up_And_Downgrade">documentation</link>.
          Gnucash 2.4 is still available under the attribute
          <literal>gnucash24</literal>.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>services.munge</literal> now runs as user (and group)
          <literal>munge</literal> instead of root. Make sure the key
          file is accessible to the daemon.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>dockerTools.buildImage</literal> now uses
          <literal>null</literal> as default value for
          <literal>tag</literal>, which indicates that the nix output
          hash will be used as tag.
        </para>
      </listitem>
      <listitem>
        <para>
          The ELK stack: <literal>elasticsearch</literal>,
          <literal>logstash</literal> and <literal>kibana</literal> has
          been upgraded from 2.* to 6.3.*. The 2.* versions have been
          <link xlink:href="https://www.elastic.co/support/eol">unsupported
          since last year</link> so they have been removed. You can
          still use the 5.* versions under the names
          <literal>elasticsearch5</literal>,
          <literal>logstash5</literal> and <literal>kibana5</literal>.
        </para>
        <para>
          The elastic beats: <literal>filebeat</literal>,
          <literal>heartbeat</literal>, <literal>metricbeat</literal>
          and <literal>packetbeat</literal> have had the same treatment:
          they now target 6.3.* as well. The 5.* versions are available
          under the names: <literal>filebeat5</literal>,
          <literal>heartbeat5</literal>, <literal>metricbeat5</literal>
          and <literal>packetbeat5</literal>
        </para>
        <para>
          The ELK-6.3 stack now comes with
          <link xlink:href="https://www.elastic.co/products/x-pack/open">X-Pack
          by default</link>. Since X-Pack is licensed under the
          <link xlink:href="https://github.com/elastic/elasticsearch/blob/master/licenses/ELASTIC-LICENSE.txt">Elastic
          License</link> the ELK packages now have an unfree license. To
          use them you need to specify
          <literal>allowUnfree = true;</literal> in your nixpkgs
          configuration.
        </para>
        <para>
          Fortunately there is also a free variant of the ELK stack
          without X-Pack. The packages are available under the names:
          <literal>elasticsearch-oss</literal>,
          <literal>logstash-oss</literal> and
          <literal>kibana-oss</literal>.
        </para>
      </listitem>
      <listitem>
        <para>
          Options
          <literal>boot.initrd.luks.devices.name.yubikey.ramfsMountPoint</literal>
          <literal>boot.initrd.luks.devices.name.yubikey.storage.mountPoint</literal>
          were removed. <literal>luksroot.nix</literal> module never
          supported more than one YubiKey at a time anyway, hence those
          options never had any effect. You should be able to remove
          them from your config without any issues.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>stdenv.system</literal> and <literal>system</literal>
          in nixpkgs now refer to the host platform instead of the build
          platform. For native builds this is not change, let alone a
          breaking one. For cross builds, it is a breaking change, and
          <literal>stdenv.buildPlatform.system</literal> can be used
          instead for the old behavior. They should be using that
          anyways for clarity.
        </para>
      </listitem>
      <listitem>
        <para>
          Groups <literal>kvm</literal> and <literal>render</literal>
          are introduced now, as systemd requires them.
        </para>
      </listitem>
    </itemizedlist>
  </section>
  <section xml:id="sec-release-18.09-notable-changes">
    <title>Other Notable Changes</title>
    <itemizedlist>
      <listitem>
        <para>
          <literal>dockerTools.pullImage</literal> relies on image
          digest instead of image tag to download the image. The
          <literal>sha256</literal> of a pulled image has to be updated.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.attrNamesToStr</literal> has been deprecated. Use
          more specific concatenation
          (<literal>lib.concat(Map)StringsSep</literal>) instead.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.addErrorContextToAttrs</literal> has been
          deprecated. Use <literal>builtins.addErrorContext</literal>
          directly.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.showVal</literal> has been deprecated. Use
          <literal>lib.traceSeqN</literal> instead.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.traceXMLVal</literal> has been deprecated. Use
          <literal>lib.traceValFn builtins.toXml</literal> instead.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.traceXMLValMarked</literal> has been deprecated.
          Use
          <literal>lib.traceValFn (x: str + builtins.toXML x)</literal>
          instead.
        </para>
      </listitem>
      <listitem>
        <para>
          The <literal>pkgs</literal> argument to NixOS modules can now
          be set directly using <literal>nixpkgs.pkgs</literal>.
          Previously, only the <literal>system</literal>,
          <literal>config</literal> and <literal>overlays</literal>
          arguments could be used to influence <literal>pkgs</literal>.
        </para>
      </listitem>
      <listitem>
        <para>
          A NixOS system can now be constructed more easily based on a
          preexisting invocation of Nixpkgs. For example:
        </para>
        <programlisting language="bash">
{
  inherit (pkgs.nixos {
    boot.loader.grub.enable = false;
    fileSystems.&quot;/&quot;.device = &quot;/dev/xvda1&quot;;
  }) toplevel kernel initialRamdisk manual;
}
</programlisting>
        <para>
          This benefits evaluation performance, lets you write Nixpkgs
          packages that depend on NixOS images and is consistent with a
          deployment architecture that would be centered around Nixpkgs
          overlays.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.traceValIfNot</literal> has been deprecated. Use
          <literal>if/then/else</literal> and
          <literal>lib.traceValSeq</literal> instead.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.traceCallXml</literal> has been deprecated.
          Please complain if you use the function regularly.
        </para>
      </listitem>
      <listitem>
        <para>
          The attribute <literal>lib.nixpkgsVersion</literal> has been
          deprecated in favor of <literal>lib.version</literal>. Please
          refer to the discussion in
          <link xlink:href="https://github.com/NixOS/nixpkgs/pull/39416#discussion_r183845745">NixOS/nixpkgs#39416</link>
          for further reference.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>lib.recursiveUpdateUntil</literal> was not acting
          according to its specification. It has been fixed to act
          according to the docstring, and a test has been added.
        </para>
      </listitem>
      <listitem>
        <para>
          The module for <literal>security.dhparams</literal> has two
          new options now:
        </para>
        <variablelist>
          <varlistentry>
            <term>
              <literal>security.dhparams.stateless</literal>
            </term>
            <listitem>
              <para>
                Puts the generated Diffie-Hellman parameters into the
                Nix store instead of managing them in a stateful manner
                in <literal>/var/lib/dhparams</literal>.
              </para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>
              <literal>security.dhparams.defaultBitSize</literal>
            </term>
            <listitem>
              <para>
                The default bit size to use for the generated
                Diffie-Hellman parameters.
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
        <note>
          <para>
            The path to the actual generated parameter files should now
            be queried using
            <literal>config.security.dhparams.params.name.path</literal>
            because it might be either in the Nix store or in a
            directory configured by
            <literal>security.dhparams.path</literal>.
          </para>
        </note>
        <note>
          <para>
            <emphasis role="strong">For developers:</emphasis>
          </para>
          <para>
            Module implementers should not set a specific bit size in
            order to let users configure it by themselves if they want
            to have a different bit size than the default (2048).
          </para>
          <para>
            An example usage of this would be:
          </para>
          <programlisting language="bash">
{ config, ... }:

{
  security.dhparams.params.myservice = {};
  environment.etc.&quot;myservice.conf&quot;.text = ''
    dhparams = ${config.security.dhparams.params.myservice.path}
  '';
}
</programlisting>
        </note>
      </listitem>
      <listitem>
        <para>
          <literal>networking.networkmanager.useDnsmasq</literal> has
          been deprecated. Use
          <literal>networking.networkmanager.dns</literal> instead.
        </para>
      </listitem>
      <listitem>
        <para>
          The Kubernetes package has been bumped to major version 1.11.
          Please consult the
          <link xlink:href="https://github.com/kubernetes/kubernetes/blob/release-1.11/CHANGELOG-1.11.md">release
          notes</link> for details on new features and api changes.
        </para>
      </listitem>
      <listitem>
        <para>
          The option
          <literal>services.kubernetes.apiserver.admissionControl</literal>
          was renamed to
          <literal>services.kubernetes.apiserver.enableAdmissionPlugins</literal>.
        </para>
      </listitem>
      <listitem>
        <para>
          Recommended way to access the Kubernetes Dashboard is via
          HTTPS (TLS) Therefore; public service port for the dashboard
          has changed to 443 (container port 8443) and scheme to https.
        </para>
      </listitem>
      <listitem>
        <para>
          The option
          <literal>services.kubernetes.apiserver.address</literal> was
          renamed to
          <literal>services.kubernetes.apiserver.bindAddress</literal>.
          Note that the default value has changed from 127.0.0.1 to
          0.0.0.0.
        </para>
      </listitem>
      <listitem>
        <para>
          The option
          <literal>services.kubernetes.apiserver.publicAddress</literal>
          was not used and thus has been removed.
        </para>
      </listitem>
      <listitem>
        <para>
          The option
          <literal>services.kubernetes.addons.dashboard.enableRBAC</literal>
          was renamed to
          <literal>services.kubernetes.addons.dashboard.rbac.enable</literal>.
        </para>
      </listitem>
      <listitem>
        <para>
          The Kubernetes Dashboard now has only minimal RBAC permissions
          by default. If dashboard cluster-admin rights are desired, set
          <literal>services.kubernetes.addons.dashboard.rbac.clusterAdmin</literal>
          to true. On existing clusters, in order for the revocation of
          privileges to take effect, the current ClusterRoleBinding for
          kubernetes-dashboard must be manually removed:
          <literal>kubectl delete clusterrolebinding kubernetes-dashboard</literal>
        </para>
      </listitem>
      <listitem>
        <para>
          The <literal>programs.screen</literal> module provides allows
          to configure <literal>/etc/screenrc</literal>, however the
          module behaved fairly counterintuitive as the config exists,
          but the package wasn't available. Since 18.09
          <literal>pkgs.screen</literal> will be added to
          <literal>environment.systemPackages</literal>.
        </para>
      </listitem>
      <listitem>
        <para>
          The module <literal>services.networking.hostapd</literal> now
          uses WPA2 by default.
        </para>
      </listitem>
      <listitem>
        <para>
          <literal>s6Dns</literal>, <literal>s6Networking</literal>,
          <literal>s6LinuxUtils</literal> and
          <literal>s6PortableUtils</literal> renamed to
          <literal>s6-dns</literal>, <literal>s6-networking</literal>,
          <literal>s6-linux-utils</literal> and
          <literal>s6-portable-utils</literal> respectively.
        </para>
      </listitem>
      <listitem>
        <para>
          The module option <literal>nix.useSandbox</literal> is now
          defaulted to <literal>true</literal>.
        </para>
      </listitem>
      <listitem>
        <para>
          The config activation script of
          <literal>nixos-rebuild</literal> now
          <link xlink:href="https://www.freedesktop.org/software/systemd/man/systemctl.html#Manager%20Lifecycle%20Commands">reloads</link>
          all user units for each authenticated user.
        </para>
      </listitem>
      <listitem>
        <para>
          The default display manager is now LightDM. To use SLiM set
          <literal>services.xserver.displayManager.slim.enable</literal>
          to <literal>true</literal>.
        </para>
      </listitem>
      <listitem>
        <para>
          NixOS option descriptions are now automatically broken up into
          individual paragraphs if the text contains two consecutive
          newlines, so it's no longer necessary to use
          <literal>&lt;/para&gt;&lt;para&gt;</literal> to start a new
          paragraph.
        </para>
      </listitem>
      <listitem>
        <para>
          Top-level <literal>buildPlatform</literal>,
          <literal>hostPlatform</literal>, and
          <literal>targetPlatform</literal> in Nixpkgs are deprecated.
          Please use their equivalents in <literal>stdenv</literal>
          instead: <literal>stdenv.buildPlatform</literal>,
          <literal>stdenv.hostPlatform</literal>, and
          <literal>stdenv.targetPlatform</literal>.
        </para>
      </listitem>
    </itemizedlist>
  </section>
</section>
