In addition to numerous new and upgraded packages, this release has the following highlights: Support is planned until the end of October 2021, handing over to 21.09. GNOME desktop environment was upgraded to 3.38, see its release notes.

The following new services were added since the last release: Keycloak, an open source identity and access management server with support for OpenID Connect, OAUTH 2.0 and SAML 2.0. See the Keycloak section of the NixOS manual for more information. Web Services Dynamic Discovery host daemon

When upgrading from a previous release, please be aware of the following incompatible changes: systemd-journal2gelf no longer parses json and expects the receiving system to handle it. How to achieve this with Graylog is described in this GitHub issue. If the services.dbus module is enabled, then the user D-Bus session is now always socket activated. The associated options services.dbus.socketActivated and services.xserver.startDbusSession have therefore been removed and you will receive a warning if they are present in your configuration. This change makes the user D-Bus session available also for non-graphical logins. rubyMinimal was removed due to being unused and unusable. The default ruby interpreter includes JIT support, which makes it reference it's compiler. Since JIT support is probably needed by some Gems, it was decided to enable this feature with all cc references by default, and allow to build a Ruby derivation without references to cc, by setting jitSupport = false; in an overlay. See #90151 for more info. Setting services.openssh.authorizedKeysFiles now also affects which keys security.pam.enableSSHAgentAuth will use. WARNING: If you are using these options in combination do make sure that any key paths you use are present in services.openssh.authorizedKeysFiles! The option fonts.enableFontDir has been renamed to . The path of font directory has also been changed to /run/current-system/sw/share/X11/fonts, for consistency with other X11 resources. A number of options have been renamed in the kicad interface. oceSupport has been renamed to withOCE, withOCCT has been renamed to withOCC, ngspiceSupport has been renamed to withNgspice, and scriptingSupport has been renamed to withScripting. Additionally, kicad/base.nix no longer provides default argument values since these are provided by kicad/default.nix. The socket for the pdns-recursor module was moved from /var/lib/pdns-recursor to /run/pdns-recursor to match upstream. Paperwork was updated to version 2. The on-disk format slightly changed, and it is not possible to downgrade from Paperwork 2 back to Paperwork 1.3. Back your documents up before upgrading. See this thread for more details. PowerDNS has been updated from 4.2.x to 4.3.x. Please be sure to review the Upgrade Notes provided by upstream before upgrading. Worth specifically noting is that the service now runs entirely as a dedicated pdns user, instead of starting as root and dropping privileges, as well as the default socket-dir location changing from /var/lib/powerdns to /run/pdns. btc1 has been abandoned upstream, and removed. cpp_ethereum (aleth) has been abandoned upstream, and removed. riak-cs package removed along with services.riak-cs module. stanchion package removed along with services.stanchion module. mutt has been updated to a new major version (2.x), which comes with some backward incompatible changes that are described in the release notes for Mutt 2.0. vim switched to Python 3, dropping all Python 2 support. boot.zfs.forceImportAll previously did nothing, but has been fixed. However its default has been changed to false to preserve the existing default behaviour. If you have this explicitly set to true, please note that your non-root pools will now be forcibly imported. openafs now points to openafs_1_8, which is the new stable release. OpenAFS 1.6 was removed. The openldap module now has support for OLC-style configuration, users of the configDir option may wish to migrate. If you continue to use configDir, ensure that olcPidFile is set to /run/slapd/slapd.pid. As a result, extraConfig and extraDatabaseConfig are removed. To help with migration, you can convert your slapd.conf file to OLC configuration with the following script (find the location of this configuration file by running systemctl status openldap, it is the -f option. TMPDIR=$(mktemp -d) slaptest -f /path/to/slapd.conf $TMPDIR slapcat -F $TMPDIR -n0 -H 'ldap:///???(!(objectClass=olcSchemaConfig))' This will dump your current configuration in LDIF format, which should be straightforward to convert into Nix settings. This does not show your schema configuration, as this is unnecessarily verbose for users of the default schemas and slaptest is buggy with schemas directly in the config file. Amazon EC2 and OpenStack Compute (nova) images now re-fetch instance meta data and user data from the instance metadata service (IMDS) on each boot. For example: stopping an EC2 instance, changing its user data, and restarting the instance will now cause it to fetch and apply the new user data. Specifically, /etc/ec2-metadata is re-populated on each boot. Some NixOS scripts that read from this directory are guarded to only run if the files they want to manipulate do not already exist, and so will not re-apply their changes if the IMDS response changes. Examples: root's SSH key is only added if /root/.ssh/authorized_keys does not exist, and SSH host keys are only set from user data if they do not exist in /etc/ssh. The rspamd services is now sandboxed. It is run as a dynamic user instead of root, so secrets and other files may have to be moved or their permissions may have to be fixed. The sockets are now located in /run/rspamd instead of /run.

The default-version of nextcloud is nextcloud20. Please note that it's not possible to upgrade nextcloud across multiple major versions! This means that it's e.g. not possible to upgrade from nextcloud18 to nextcloud20 in a single deploy. The package can be manually upgraded by setting to nextcloud20. The setting defaults to 127.0.0.1 now, making Redis listen on the loopback interface only, and not all public network interfaces. NixOS now emits a deprecation warning if systemd's StartLimitInterval setting is used in a serviceConfig section instead of in a unitConfig; that setting is deprecated and now undocumented for the service section by systemd upstream, but still effective and somewhat buggy there, which can be confusing. See #45785 for details. All services should use or StartLimitIntervalSec in instead. The Unbound DNS resolver service (services.unbound) has been refactored to allow reloading, control sockets and to fix startup ordering issues. It is now possible to enable a local UNIX control socket for unbound by setting the option. Previously we just applied a very minimal set of restrictions and trusted unbound to properly drop root privs and capabilities. As of this we are (for the most part) just using the upstream example unit file for unbound. The main difference is that we start unbound as unbound user with the required capabilities instead of letting unbound do the chroot & uid/gid changes. The upstream unit configuration this is based on is a lot stricter with all kinds of permissions then our previous variant. It also came with the default of having the Type set to notify, therefore we are now also using the unbound-with-systemd package here. Unbound will start up, read the configuration files and start listening on the configured ports before systemd will declare the unit active (running). This will likely help with startup order and the occasional race condition during system activation where the DNS service is started but not yet ready to answer queries. Services depending on nss-lookup.target or unbound.service are now be able to use unbound when those targets have been reached. Aditionally to the much stricter runtime environmet the /dev/urandom mount lines we previously had in the code (that would randomly failed during the stop-phase) have been removed as systemd will take care of those for us. The preStart script is now only required if we enabled the trust anchor updates (which are still enabled by default). Another benefit of the refactoring is that we can now issue reloads via either pkill -HUP unbound and systemctl reload unbound to reload the running configuration without taking the daemon offline. A prerequisite of this was that unbound configuration is available on a well known path on the file system. We are using the path /etc/unbound/unbound.conf as that is the default in the CLI tooling which in turn enables us to use unbound-control without passing a custom configuration location. NixOS now defaults to the unified cgroup hierarchy (cgroupsv2). See the Fedora Article for 31 for details on why this is desirable, and how it impacts containers. If you want to run containers with a runtime that does not yet support cgroupsv2, you can switch back to the old behaviour by setting = false; and rebooting.