rl-1903.xml

<section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-release-19.03">
 <title>Release 19.03 (“Koi”, 2019/03/??)</title>

 <section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-release-19.03-highlights">
  <title>Highlights</title>

  <para>
   In addition to numerous new and upgraded packages, this release has the
   following highlights:
  </para>

  <itemizedlist>
   <listitem>
    <para>
     The default Python 3 interpreter is now CPython 3.7 instead of CPython
     3.6.
    </para>
   </listitem>
   <listitem>
    <para>
     Added the Pantheon desktop environment. It can be enabled through
     <varname>services.xserver.desktopManager.pantheon.enable</varname>.
    </para>
    <note>
     <para>
      By default, <varname>services.xserver.desktopManager.pantheon</varname>
      enables LightDM as a display manager, as pantheon's screen locking
      implementation relies on it.
     </para>
     <para>
      Because of that it is recommended to leave LightDM enabled. If you'd like
      to disable it anyway, set
      <option>services.xserver.displayManager.lightdm.enable</option> to
      <literal>false</literal> and enable your preferred display manager.
     </para>
    </note>
    <para>
     Also note that Pantheon's LightDM greeter is not enabled by default,
     because it has numerous issues in NixOS and isn't optimal for use here
     yet.
    </para>
   </listitem>
   <listitem>
    <para>
     A major refactoring of the Kubernetes module has been completed.
     Refactorings primarily focus on decoupling components and enhancing
     security. Two-way TLS and RBAC has been enabled by default for all
     components, which slightly changes the way the module is configured. See:
     <xref linkend="sec-kubernetes"/> for details.
    </para>
   </listitem>
   <listitem>
     <para>
       There is now a set of <option>confinement</option> options for
       <option>systemd.services</option>, which allows to restrict services
       into a <citerefentry>
        <refentrytitle>chroot</refentrytitle>
        <manvolnum>2</manvolnum>
      </citerefentry>ed environment that only contains the store paths from
      the runtime closure of the service.
     </para>
   </listitem>
   <listitem>
     <para>
       A UEFI installer image for Aarch64 is now
       <link xlink:href="https://hydra.nixos.org/job/nixos/release-19.03/nixos.iso_minimal.aarch64-linux/latest">
         built by Hydra</link>.
       It should work on all devices with a UEFI implementation
       such as upstream u-boot.
     </para>
   </listitem>
  </itemizedlist>
 </section>

 <section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-release-19.03-new-modules">
  <title>New Modules</title>
  <para>
   The following new modules were added since the last release:
  </para>

  <itemizedlist>
   <listitem>
    <para><filename>security/google_oslogin.nix</filename></para>
    <para>
     There is a new <varname>security.googleOsLogin</varname> module for using
     <link xlink:href="https://cloud.google.com/compute/docs/instances/managing-instance-access">OS
     Login</link> to manage SSH access to Google Compute Engine instances,
     which supersedes the imperative and broken
     <literal>google-accounts-daemon</literal> used in
     <literal>nixos/modules/virtualisation/google-compute-config.nix</literal>.
    </para>
   </listitem>

   <listitem>
    <para><filename>services/misc/beanstalkd.nix</filename></para>
    <para>
     There is a new <varname>services.cockroachdb</varname> module for running
     CockroachDB databases. NixOS now ships with CockroachDB 2.1.x as well,
     available on <literal>x86_64-linux</literal> and
     <literal>aarch64-linux</literal>.
    </para>
   </listitem>

   <listitem>
    <para>
     <filename>security/duosec.nix</filename>
    </para>
    <para>
     The <link xlink:href="https://duo.com/docs/duounix">PAM module for Duo
     Security</link> has been enabled for use. One can configure it using the
     <option>security.duosec</option> options along with the corresponding PAM
     option in
     <option>security.pam.services.&lt;name?&gt;.duoSecurity.enable</option>.
    </para>
   </listitem>
   <listitem><para><filename>config/appstream.nix</filename></para></listitem>
   <listitem><para><filename>config/xdg/sounds.nix</filename></para></listitem>
   <listitem><para><filename>hardware/acpilight.nix</filename></para></listitem>
   <listitem><para><filename>hardware/ledger.nix</filename></para></listitem>
   <listitem><para><filename>programs/dmrconfig.nix</filename></para></listitem>
   <listitem><para><filename>programs/iotop.nix</filename></para></listitem>
   <listitem><para><filename>programs/mininet.nix</filename></para></listitem>
   <listitem><para><filename>programs/nm-applet.nix</filename></para></listitem>
   <listitem><para><filename>programs/wavemon.nix</filename></para></listitem>
   <listitem><para><filename>security/google_oslogin.nix</filename></para></listitem>
   <listitem><para><filename>security/misc.nix</filename></para></listitem>
   <listitem><para><filename>services/desktops/gnome3/rygel.nix</filename></para></listitem>
   <listitem><para><filename>services/desktops/gsignond.nix</filename></para></listitem>
   <listitem><para><filename>services/hardware/bolt.nix</filename></para></listitem>
   <listitem><para><filename>services/hardware/lirc.nix</filename></para></listitem>
   <listitem><para><filename>services/hardware/ratbagd.nix</filename></para></listitem>
   <listitem><para><filename>services/hardware/triggerhappy.nix</filename></para></listitem>
   <listitem><para><filename>services/hardware/vdr.nix</filename></para></listitem>
   <listitem><para><filename>services/mail/davmail.nix</filename></para></listitem>
   <listitem><para><filename>services/mail/roundcube.nix</filename></para></listitem>
   <listitem><para><filename>services/mail/rss2email.nix</filename></para></listitem>
   <listitem><para><filename>services/misc/beanstalkd.nix</filename></para></listitem>
   <listitem><para><filename>services/misc/bees.nix</filename></para></listitem>
   <listitem><para><filename>services/misc/headphones.nix</filename></para></listitem>
   <listitem><para><filename>services/misc/lidarr.nix</filename></para></listitem>
   <listitem><para><filename>services/misc/sickbeard.nix</filename></para></listitem>
   <listitem><para><filename>services/misc/weechat.nix</filename></para></listitem>
   <listitem><para><filename>services/misc/zoneminder.nix</filename></para></listitem>
   <listitem><para><filename>services/monitoring/alerta.nix</filename></para></listitem>
   <listitem><para><filename>services/monitoring/kapacitor.nix</filename></para></listitem>
   <listitem><para><filename>services/networking/iperf3.nix</filename></para></listitem>
   <listitem><para><filename>services/networking/knot.nix</filename></para></listitem>

  </itemizedlist>
 </section>

 <section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-release-19.03-incompatibilities">
  <title>Backward Incompatibilities</title>

  <para>
   When upgrading from a previous release, please be aware of the following
   incompatible changes:
  </para>

  <itemizedlist>
   <listitem>
    <para>
     The minimum version of Nix required to evaluate Nixpkgs is now 2.0.
    </para>
    <itemizedlist>
     <listitem>
      <para>
       For users of NixOS 18.03 and 19.03, NixOS defaults to Nix 2.0, but
       supports using Nix 1.11 by setting <literal>nix.package =
       pkgs.nix1;</literal>. If this option is set to a Nix 1.11 package, you
       will need to either unset the option or upgrade it to Nix 2.0.
      </para>
     </listitem>
     <listitem>
      <para>
       For users of NixOS 17.09, you will first need to upgrade Nix by setting
       <literal>nix.package = pkgs.nixStable2;</literal> and run
       <command>nixos-rebuild switch</command> as the <literal>root</literal>
       user.
      </para>
     </listitem>
     <listitem>
      <para>
       For users of a daemon-less Nix installation on Linux or macOS, you can
       upgrade Nix by running <command>curl https://nixos.org/nix/install |
       sh</command>, or prior to doing a channel update, running
       <command>nix-env -iA nix</command>.
      </para>
      <para>
       If you have already run a channel update and Nix is no longer able to
       evaluate Nixpkgs, the error message printed should provide adequate
       directions for upgrading Nix.
      </para>
     </listitem>
     <listitem>
      <para>
       For users of the Nix daemon on macOS, you can upgrade Nix by running
       <command>sudo -i sh -c 'nix-channel --update &amp;&amp; nix-env -iA
       nixpkgs.nix'; sudo launchctl stop org.nixos.nix-daemon; sudo launchctl
       start org.nixos.nix-daemon</command>.
      </para>
     </listitem>
    </itemizedlist>
   </listitem>
   <listitem>
    <para>
     The <varname>buildPythonPackage</varname> function now sets
     <varname>strictDeps = true</varname> to help distinguish between native
     and non-native dependencies in order to improve cross-compilation
     compatibility. Note however that this may break user expressions.
    </para>
   </listitem>
   <listitem>
    <para>
     The <varname>buildPythonPackage</varname> function now sets <varname>LANG
     = C.UTF-8</varname> to enable Unicode support. The
     <varname>glibcLocales</varname> package is no longer needed as a build
     input.
    </para>
   </listitem>
   <listitem>
    <para>
     The Syncthing state and configuration data has been moved from
     <varname>services.syncthing.dataDir</varname> to the newly defined
     <varname>services.syncthing.configDir</varname>, which default to
     <literal>/var/lib/syncthing/.config/syncthing</literal>. This change makes
     possible to share synced directories using ACLs without Syncthing
     resetting the permission on every start.
    </para>
   </listitem>
   <listitem>
    <para>
     The <literal>ntp</literal> module now has sane default restrictions. If
     you're relying on the previous defaults, which permitted all queries and
     commands from all firewall-permitted sources, you can set
     <varname>services.ntp.restrictDefault</varname> and
     <varname>services.ntp.restrictSource</varname> to <literal>[]</literal>.
    </para>
   </listitem>
   <listitem>
    <para>
     Package <varname>rabbitmq_server</varname> is renamed to
     <varname>rabbitmq-server</varname>.
    </para>
   </listitem>
   <listitem>
    <para>
     The <literal>light</literal> module no longer uses setuid binaries, but
     udev rules. As a consequence users of that module have to belong to the
     <literal>video</literal> group in order to use the executable (i.e.
     <literal>users.users.yourusername.extraGroups = ["video"];</literal>).
    </para>
   </listitem>
   <listitem>
    <para>
     Buildbot now supports Python 3 and its packages have been moved to
     <literal>pythonPackages</literal>. The options
     <option>services.buildbot-master.package</option> and
     <option>services.buildbot-worker.package</option> can be used to select
     the Python 2 or 3 version of the package.
    </para>
   </listitem>
   <listitem>
    <para>
     Options
     <literal>services.znc.confOptions.networks.<replaceable>name</replaceable>.userName</literal>
     and
     <literal>services.znc.confOptions.networks.<replaceable>name</replaceable>.modulePackages</literal>
     were removed. They were never used for anything and can therefore safely
     be removed.
    </para>
   </listitem>
   <listitem>
    <para>
     Package <literal>wasm</literal> has been renamed
     <literal>proglodyte-wasm</literal>. The package <literal>wasm</literal>
     will be pointed to <literal>ocamlPackages.wasm</literal> in 19.09, so make
     sure to update your configuration if you want to keep
     <literal>proglodyte-wasm</literal>
    </para>
   </listitem>
   <listitem>
    <para>
     When the <literal>nixpkgs.pkgs</literal> option is set, NixOS will no
     longer ignore the <literal>nixpkgs.overlays</literal> option. The old
     behavior can be recovered by setting <literal>nixpkgs.overlays =
     lib.mkForce [];</literal>.
    </para>
   </listitem>
   <listitem>
    <para>
     OpenSMTPD has been upgraded to version 6.4.0p1. This release makes
     backwards-incompatible changes to the configuration file format. See
     <command>man smtpd.conf</command> for more information on the new file
     format.
    </para>
   </listitem>
   <listitem>
    <para>
     The versioned <varname>postgresql</varname> have been renamed to use
     underscore number separators. For example, <varname>postgresql96</varname>
     has been renamed to <varname>postgresql_9_6</varname>.
    </para>
   </listitem>
   <listitem>
    <para>
     Package <literal>consul-ui</literal> and passthrough
     <literal>consul.ui</literal> have been removed. The package
     <literal>consul</literal> now uses upstream releases that vendor the UI
     into the binary. See
     <link xlink:href="https://github.com/NixOS/nixpkgs/pull/48714#issuecomment-433454834">#48714</link>
     for details.
    </para>
   </listitem>
   <listitem>
    <para>
     Slurm introduces the new option
     <literal>services.slurm.stateSaveLocation</literal>, which is now set to
     <literal>/var/spool/slurm</literal> by default (instead of
     <literal>/var/spool</literal>). Make sure to move all files to the new
     directory or to set the option accordingly.
    </para>
    <para>
     The slurmctld now runs as user <literal>slurm</literal> instead of
     <literal>root</literal>. If you want to keep slurmctld running as
     <literal>root</literal>, set <literal>services.slurm.user =
     root</literal>.
    </para>
    <para>
     The options <literal>services.slurm.nodeName</literal> and
     <literal>services.slurm.partitionName</literal> are now sets of strings to
     correctly reflect that fact that each of these options can occour more
     than once in the configuration.
    </para>
   </listitem>
   <listitem>
    <para>
     The <literal>solr</literal> package has been upgraded from 4.10.3 to 7.5.0
     and has undergone some major changes. The <literal>services.solr</literal>
     module has been updated to reflect these changes. Please review
     http://lucene.apache.org/solr/ carefully before upgrading.
    </para>
   </listitem>
   <listitem>
    <para>
     Package <literal>ckb</literal> is renamed to <literal>ckb-next</literal>,
     and options <literal>hardware.ckb.*</literal> are renamed to
     <literal>hardware.ckb-next.*</literal>.
    </para>
   </listitem>
   <listitem>
    <para>
     The option
     <literal>services.xserver.displayManager.job.logToFile</literal> which was
     previously set to <literal>true</literal> when using the display managers
     <literal>lightdm</literal>, <literal>sddm</literal> or
     <literal>xpra</literal> has been reset to the default value
     (<literal>false</literal>).
    </para>
   </listitem>
   <listitem>
    <para>
     Network interface indiscriminate NixOS firewall options
     (<literal>networking.firewall.allow*</literal>) are now preserved when
     also setting interface specific rules such as
     <literal>networking.firewall.interfaces.en0.allow*</literal>. These rules
     continue to use the pseudo device "default"
     (<literal>networking.firewall.interfaces.default.*</literal>), and
     assigning to this pseudo device will override the
     (<literal>networking.firewall.allow*</literal>) options.
    </para>
   </listitem>
   <listitem>
    <para>
     The <literal>nscd</literal> service now disables all caching of
     <literal>passwd</literal> and <literal>group</literal> databases by
     default. This was interferring with the correct functioning of the
     <literal>libnss_systemd.so</literal> module which is used by
     <literal>systemd</literal> to manage uids and usernames in the presence of
     <literal>DynamicUser=</literal> in systemd services. This was already the
     default behaviour in presence of <literal>services.sssd.enable =
     true</literal> because nscd caching would interfere with
     <literal>sssd</literal> in unpredictable ways as well. Because we're using
     nscd not for caching, but for convincing glibc to find NSS modules in the
     nix store instead of an absolute path, we have decided to disable caching
     globally now, as it's usually not the behaviour the user wants and can
     lead to surprising behaviour. Furthermore, negative caching of host
     lookups is also disabled now by default. This should fix the issue of dns
     lookups failing in the presence of an unreliable network.
    </para>
    <para>
     If the old behaviour is desired, this can be restored by setting the
     <literal>services.nscd.config</literal> option with the desired caching
     parameters.
<programlisting>
     services.nscd.config =
     ''
     server-user             nscd
     threads                 1
     paranoia                no
     debug-level             0

     enable-cache            passwd          yes
     positive-time-to-live   passwd          600
     negative-time-to-live   passwd          20
     suggested-size          passwd          211
     check-files             passwd          yes
     persistent              passwd          no
     shared                  passwd          yes

     enable-cache            group           yes
     positive-time-to-live   group           3600
     negative-time-to-live   group           60
     suggested-size          group           211
     check-files             group           yes
     persistent              group           no
     shared                  group           yes

     enable-cache            hosts           yes
     positive-time-to-live   hosts           600
     negative-time-to-live   hosts           5
     suggested-size          hosts           211
     check-files             hosts           yes
     persistent              hosts           no
     shared                  hosts           yes
     '';
     </programlisting>
     See
     <link xlink:href="https://github.com/NixOS/nixpkgs/pull/50316">#50316</link>
     for details.
    </para>
   </listitem>
   <listitem>
    <para>
     GitLab Shell previously used the nix store paths for the
     <literal>gitlab-shell</literal> command in its
     <literal>authorized_keys</literal> file, which might stop working after
     garbage collection. To circumvent that, we regenerated that file on each
     startup. As <literal>gitlab-shell</literal> has now been changed to use
     <literal>/var/run/current-system/sw/bin/gitlab-shell</literal>, this is
     not necessary anymore, but there might be leftover lines with a nix store
     path. Regenerate the <literal>authorized_keys</literal> file via
     <command>sudo -u git -H gitlab-rake gitlab:shell:setup</command> in that
     case.
    </para>
   </listitem>
   <listitem>
    <para>
     The <literal>pam_unix</literal> account module is now loaded with its
     control field set to <literal>required</literal> instead of
     <literal>sufficient</literal>, so that later PAM account modules that
     might do more extensive checks are being executed. Previously, the whole
     account module verification was exited prematurely in case a nss module
     provided the account name to <literal>pam_unix</literal>. The LDAP and
     SSSD NixOS modules already add their NSS modules when enabled. In case
     your setup breaks due to some later PAM account module previously
     shadowed, or failing NSS lookups, please file a bug. You can get back the
     old behaviour by manually setting <literal>
<![CDATA[security.pam.services.<name?>.text]]>
     </literal>.
    </para>
   </listitem>
   <listitem>
    <para>
     The <literal>pam_unix</literal> password module is now loaded with its
     control field set to <literal>sufficient</literal> instead of
     <literal>required</literal>, so that password managed only by later PAM
     password modules are being executed. Previously, for example, changing an
     LDAP account's password through PAM was not possible: the whole password
     module verification was exited prematurely by <literal>pam_unix</literal>,
     preventing <literal>pam_ldap</literal> to manage the password as it
     should.
    </para>
   </listitem>
   <listitem>
    <para>
     <literal>fish</literal> has been upgraded to 3.0. It comes with a number
     of improvements and backwards incompatible changes. See the
     <literal>fish</literal>
     <link xlink:href="https://github.com/fish-shell/fish-shell/releases/tag/3.0.0">release
     notes</link> for more information.
    </para>
   </listitem>
   <listitem>
    <para>
     The ibus-table input method has had a change in config format, which
     causes all previous settings to be lost. See
     <link xlink:href="https://github.com/mike-fabian/ibus-table/commit/f9195f877c5212fef0dfa446acb328c45ba5852b">this
     commit message</link> for details.
    </para>
   </listitem>
   <listitem>
    <para>
     NixOS module system type <literal>types.optionSet</literal> and
     <literal>lib.mkOption</literal> argument <literal>options</literal> are
     deprecated. Use <literal>types.submodule</literal> instead.
     (<link xlink:href="https://github.com/NixOS/nixpkgs/pull/54637">#54637</link>)
    </para>
   </listitem>
   <listitem>
    <para>
     <literal>matrix-synapse</literal> has been updated to version 0.99. It
     will <link xlink:href="https://github.com/matrix-org/synapse/pull/4509">no
     longer generate a self-signed certificate on first launch</link> and will
     be
     <link xlink:href="https://matrix.org/blog/2019/02/05/synapse-0-99-0/">the
     last version to accept self-signed certificates</link>. As such, it is now
     recommended to use a proper certificate verified by a root CA (for example
     Let's Encrypt). The new <link linkend="module-services-matrix">manual
     chapter on Matrix</link> contains a working example of using nginx as a
     reverse proxy in front of <literal>matrix-synapse</literal>, using Let's
     Encrypt certificates.
    </para>
   </listitem>
   <listitem>
    <para>
     <literal>mailutils</literal> now works by default when
     <literal>sendmail</literal> is not in a setuid wrapper. As a consequence,
     the <literal>sendmailPath</literal> argument, having lost its main use,
     has been removed.
    </para>
   </listitem>
   <listitem>
    <para>
     <literal>graylog</literal> has been upgraded from version 2.* to 3.*. Some
     setups making use of extraConfig (especially those exposing Graylog via
     reverse proxies) need to be updated as upstream removed/replaced some
     settings. See
     <link xlink:href="http://docs.graylog.org/en/3.0/pages/upgrade/graylog-3.0.html#simplified-http-interface-configuration">Upgrading
     Graylog</link> for details.
    </para>
   </listitem>
   <listitem>
    <para>
      The option <literal>users.ldap.bind.password</literal> was renamed to <literal>users.ldap.bind.passwordFile</literal>,
      and needs to be readable by the <literal>nslcd</literal> user.
      Same applies to the new <literal>users.ldap.daemon.rootpwmodpwFile</literal> option.
    </para>
   </listitem>
   <listitem>
     <para>
       <literal>nodejs-6_x</literal> is end-of-life.
       <literal>nodejs-6_x</literal>, <literal>nodejs-slim-6_x</literal> and
       <literal>nodePackages_6_x</literal> are removed.
     </para>
   </listitem>
  </itemizedlist>
 </section>

 <section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-release-19.03-notable-changes">
  <title>Other Notable Changes</title>

  <itemizedlist>
   <listitem>
    <para>
     The <option>services.matomo</option> module gained the option
     <option>services.matomo.package</option> which determines the used Matomo
     version.
    </para>
    <para>
     The Matomo module now also comes with the systemd service
     <literal>matomo-archive-processing.service</literal> and a timer that
     automatically triggers archive processing every hour. This means that you
     can safely
     <link xlink:href="https://matomo.org/docs/setup-auto-archiving/#disable-browser-triggers-for-matomo-archiving-and-limit-matomo-reports-to-updating-every-hour">
     disable browser triggers for Matomo archiving </link> at
     <literal>Administration > System > General Settings</literal>.
    </para>
    <para>
     Additionally, you can enable to
     <link xlink:href="https://matomo.org/docs/privacy/#step-2-delete-old-visitors-logs">
     delete old visitor logs </link> at <literal>Administration > System >
     Privacy</literal>, but make sure that you run <literal>systemctl start
     matomo-archive-processing.service</literal> at least once without errors
     if you have already collected data before, so that the reports get
     archived before the source data gets deleted.
    </para>
   </listitem>
   <listitem>
    <para>
     <literal>composableDerivation</literal> along with supporting library
     functions has been removed.
    </para>
   </listitem>
   <listitem>
    <para>
     The deprecated <literal>truecrypt</literal> package has been removed and
     <literal>truecrypt</literal> attribute is now an alias for
     <literal>veracrypt</literal>. VeraCrypt is backward-compatible with
     TrueCrypt volumes. Note that <literal>cryptsetup</literal> also supports
     loading TrueCrypt volumes.
    </para>
   </listitem>
   <listitem>
    <para>
     The Kubernetes DNS addons, kube-dns, has been replaced with CoreDNS. This
     change is made in accordance with Kubernetes making CoreDNS the official
     default starting from
     <link xlink:href="https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.11.md#sig-cluster-lifecycle">Kubernetes
     v1.11</link>. Please beware that upgrading DNS-addon on existing clusters
     might induce minor downtime while the DNS-addon terminates and
     re-initializes. Also note that the DNS-service now runs with 2 pod
     replicas by default. The desired number of replicas can be configured
     using: <option>services.kubernetes.addons.dns.replicas</option>.
    </para>
   </listitem>
   <listitem>
    <para>
     The quassel-webserver package and module was removed from nixpkgs due to
     the lack of maintainers.
    </para>
   </listitem>
   <listitem>
    <para>
     The manual gained a <link linkend="module-services-matrix"> new chapter on
     self-hosting <literal>matrix-synapse</literal> and
     <literal>riot-web</literal> </link>, the most prevalent server and client
     implementations for the
     <link xlink:href="https://matrix.org/">Matrix</link> federated
     communication network.
    </para>
   </listitem>
   <listitem>
    <para>
     The astah-community package was removed from nixpkgs due to it being
     discontinued and the downloads not being available anymore.
    </para>
   </listitem>
   <listitem>
    <para>
     The httpd service now saves log files with a .log file extension by
     default for easier integration with the logrotate service.
    </para>
   </listitem>
   <listitem>
    <para>
     The owncloud server packages and httpd subservice module were removed from
     nixpkgs due to the lack of maintainers.
    </para>
   </listitem>
   <listitem>
    <para>
     It is possible now to uze ZRAM devices as general purpose ephemeral block
     devices, not only as swap. Using more than 1 device as ZRAM swap is no
     longer recommended, but is still possible by setting
     <literal>zramSwap.swapDevices</literal> explicitly.
    </para>
    <para>
     ZRAM algorithm can be changed now.
    </para>
    <para>
     Changes to ZRAM algorithm are applied during <literal>nixos-rebuild
     switch</literal>, so make sure you have enough swap space on disk to
     survive ZRAM device rebuild. Alternatively, use <literal>nixos-rebuild
     boot; reboot</literal>.
    </para>
   </listitem>
   <listitem>
    <para>
     Flat volumes are now disabled by default in
     <literal>hardware.pulseaudio</literal>. This has been done to prevent
     applications, which are unaware of this feature, setting their volumes to
     100% on startup causing harm to your audio hardware and potentially your
     ears.
    </para>
    <note>
     <para>
      With this change application specific volumes are relative to the master
      volume which can be adjusted independently, whereas before they were
      absolute; meaning that in effect, it scaled the device-volume with the
      volume of the loudest application.
     </para>
    </note>
   </listitem>
   <listitem>
    <para>
     The
     <link xlink:href="https://github.com/DanielAdolfsson/ndppd"><literal>ndppd</literal></link>
     module now supports <link linkend="opt-services.ndppd.enable">all config
     options</link> provided by the current upstream version as service
     options. Additionally the <literal>ndppd</literal> package doesn't contain
     the systemd unit configuration from upstream anymore, the unit is
     completely configured by the NixOS module now.
    </para>
   </listitem>
   <listitem>
    <para>
     New installs of NixOS will default to the Redmine 4.x series unless
     otherwise specified in <literal>services.redmine.package</literal> while
     existing installs of NixOS will default to the Redmine 3.x series.
    </para>
   </listitem>
   <listitem>
    <para>
     The <link linkend="opt-services.grafana.enable">Grafana module</link> now
     supports declarative
     <link xlink:href="http://docs.grafana.org/administration/provisioning/">datasource
     and dashboard</link> provisioning.
    </para>
   </listitem>
   <listitem>
    <para>
     The use of insecure ports on kubernetes has been deprecated. Thus options:
     <varname>services.kubernetes.apiserver.port</varname> and
     <varname>services.kubernetes.controllerManager.port</varname> has been
     renamed to <varname>.insecurePort</varname>, and default of both options
     has changed to 0 (disabled).
    </para>
   </listitem>
   <listitem>
    <para>
     The default value of
     <varname>services.kubernetes.apiserver.bindAddress</varname> has changed
     from 127.0.0.1 to 0.0.0.0, allowing the apiserver to be accessible from
     outside the master node itself. If the apiserver insecurePort is enabled,
     it is strongly recommended to only bind on the loopback interface. See:
     <varname>services.kubernetes.apiserver.insecurebindAddress</varname>.
    </para>
   </listitem>
   <listitem>
    <para>
     The option
     <varname>services.kubernetes.apiserver.allowPrivileged</varname> and
     <varname>services.kubernetes.kubelet.allowPrivileged</varname> now
     defaults to false. Disallowing privileged containers on the cluster.
    </para>
   </listitem>
   <listitem>
    <para>
     The kubernetes module no longer adds the kubernetes package to
     <varname>environment.systemPackages</varname> implicitly.
    </para>
   </listitem>
   <listitem>
    <para>
     The <literal>intel</literal> driver has been removed from the default list
     of <link linkend="opt-services.xserver.videoDrivers">X.org video
     drivers</link>. The <literal>modesetting</literal> driver should take over
     automatically, it is better maintained upstream and has less problems with
     advanced X11 features. This can lead to a change in the output names used
     by <command>xrandr</command>. Some performance regressions on some GPU
     models might happen. Some OpenCL and VA-API applications might also break
     (Beignet seems to provide OpenCL support with
     <literal>modesetting</literal> driver, too). Kernel mode setting API does
     not support backlight control, so <command>xbacklight</command> tool will
     not work; backlight level can be controlled directly via
     <filename>/sys/</filename> or with <command>brightnessctl</command> or
     <command>light</command>. Users
     who need this functionality more than multi-output XRandR are advised to
     add <literal>intel</literal> to <varname>videoDrivers</varname> and report
     an issue (or provide additional details in an existing one).
    </para>
   </listitem>
   <listitem>
    <para>
     Openmpi has been updated to version 4.0.0, which removes some deprecated
     MPI-1 symbols. This may break some older applications that still rely on
     those symbols. An upgrade guide can be found
     <link xlink:href="https://www.open-mpi.org/faq/?category=mpi-removed">here</link>.
    </para>
   </listitem>
   <listitem>
    <para>
     The nginx package now relies on OpenSSL 1.1 and supports TLS 1.3 by
     default. You can set the protocols used by the nginx service using
     <xref linkend="opt-services.nginx.sslProtocols"/>.
    </para>
   </listitem>
   <listitem>
    <para>
     A new subcommand <command>nixos-rebuild edit</command> was added.
    </para>
   </listitem>
   <listitem>
     <para>
       <function>stdenv.mkDerivation</function> may now be passed
       <varname>pname</varname> and <varname>version</varname> attributes
       instead of <varname>name</varname>, and will now automatically
       construct the package name by joining them with a dash.
     </para>
   </listitem>
   <listitem>
     <para>
       The Sway tiling Wayland compositor has been updated to version 1.0, and the
       corresponding NixOS module has been refined to fix some bugs.
     </para>
   </listitem>
  </itemizedlist>
 </section>
</section>