<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>
  </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-services">
  <title>New Services</title>

  <para>
   The following new services were added since the last release:
  </para>

  <itemizedlist>
   <listitem>
    <para>
     <literal>./programs/nm-applet.nix</literal>
    </para>
   </listitem>
   <listitem>
    <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>
  </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 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 seperators. 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
     previosuly 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>
     <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>
  </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>
   </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 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>
      Default algorithm for ZRAM swap was changed to <literal>zstd</literal>.
     </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>
  </itemizedlist>
 </section>
</section>
