- Peertube now uses services.redis.servers to start a new redis server, instead of using a global redis server.
  This improves compatibility with other services that use redis.

  Redis database is used for storage only cache and job queue. More information can be found here - [Peertube architecture](https://docs.joinpeertube.org/contribute-architecture).

  If you do want to save the redis database, you can use the following commands before upgrade OS:
  ```bash
  redis-cli save
  sudo mkdir /var/lib/redis-peertube
  sudo cp /var/lib/redis/dump.rdb /var/lib/redis-peertube/dump.rdb
  ```
- Added the `keter` NixOS module. Keter reverse proxies requests to your loaded application based on virtual hostnames.

- If you are using Wayland you can choose to use the Ozone Wayland support
  in Chrome and several Electron apps by setting the environment variable
  `NIXOS_OZONE_WL=1` (for example via
  `environment.sessionVariables.NIXOS_OZONE_WL = "1"`).
  This is not enabled by default because Ozone Wayland is
  still under heavy development and behavior is not always flawless.
  Furthermore, not all Electron apps use the latest Electron versions.

- A new option group `systemd.network.wait-online` was added, with options to configure `systemd-networkd-wait-online.service`:
  - `anyInterface` allows specifying that the network should be considered online when *at least one* interface is online (useful on laptops)
  - `timeout` defines how long to wait for the network to come online
  - `extraArgs` for everything else

- The `influxdb2` package was split into `influxdb2-server` and
  `influxdb2-cli`, matching the split that took place upstream. A
  combined `influxdb2` package is still provided in this release for
  backwards compatibility, but will be removed at a later date.

- The `unifi` package was switched from `unifi6` to `unifi7`.
  Direct downgrades from Unifi 7 to Unifi 6 are not possible and require restoring from a backup made by Unifi 6.

- `programs.zsh.autosuggestions.strategy` now takes a list of strings instead of a string.

- The `asterisk` and `asterisk-stable` packages were switched from `asterisk_18` to the newly-packaged `asterisk_19`. Asterisk 13 and 17 have been removed as they have reached their end of life.

- The `services.unifi.openPorts` option default value of `true` is now deprecated and will be changed to `false` in 22.11.
  Configurations using this default will print a warning when rebuilt.

- The `services.unifi-video.openPorts` option default value of `true` is now deprecated and will be changed to `false` in 22.11.
  Configurations using this default will print a warning when rebuilt.

- `security.acme` certificates will now correctly check for CA
  revocation before reaching their minimum age.

- Removing domains from `security.acme.certs._name_.extraDomainNames`
  will now correctly remove those domains during rebuild/renew.

- MariaDB is now offered in several versions, not just the newest one.
  So if you have a need for running MariaDB 10.4 for example, you can now just set `services.mysql.package = pkgs.mariadb_104;`.
  In general, it is recommended to run the newest version, to get the newest features, while sticking with an LTS version will most likely provide a more stable experience.
  Sometimes software is also incompatible with the newest version of MariaDB.

- The option
  [programs.ssh.enableAskPassword](#opt-programs.ssh.enableAskPassword) was
  added, decoupling the setting of `SSH_ASKPASS` from
  `services.xserver.enable`. This allows easy usage in non-X11 environments,
  e.g. Wayland.

- [programs.ssh.knownHosts](#opt-programs.ssh.knownHosts) has gained an `extraHostNames`
  option to augment `hostNames`. It is now possible to use the attribute name of a `knownHosts`
  entry as the primary host name and specify secondary host names using `extraHostNames` without
  having to duplicate the primary host name.

- The `services.stubby` module was converted to a [settings-style](https://github.com/NixOS/rfcs/blob/master/rfcs/0042-config-option.md) configuration.