This allows the VM to provide a `configuration.nix` file to the VM.
The test doesn't work in sandbox because it needs Internet (however it
works interactively).
The Openstack metadata service exposes the EC2 API. We use the
existing `ec2.nix` module to configure the hostname and ssh keys of an
Openstack Instance.
A test checks the ssh server is well configured.
This is mainly to reduce the size of the image (700MB). Also,
declarative features provided by cloud-init are not really useful
since we would prefer to use our `configuration.nix` file instead.
I've been asked, on numerous occasions, by my students and others, how
to 'sudo' on NixOS.
Of course new users could read up in the manual on how to do that, or we
could make it more accessible for them by simply making it visible in
the default `configuration.nix` file.
Additionally, as raised in [1], replacing `guest` with something more
recognizable could be potentially beneficial to new users. I've
opted for `jane` for now.
[1]: https://github.com/NixOS/nixpkgs/pull/54519#issuecomment-457012223
The motivation for this is that some applications are unaware
of this feature and can set their volume to 100% on startup
harming people ears and possiblly blowing someone's audio
setup.
I noticed this in #54594 and by extension epiphany[0].
Please also note that many other distros have this default for
the reason outlined above.
Closes#5632#54594
[0]: https://bugzilla.gnome.org/show_bug.cgi?id=675217
Systemd provides some functionality to escape strings that are supposed
to be part of a unit name[1]. This seems to be used for interface names
in `sys-subsystem-net-devices-{interface}.device` and breaks
wpa_supplicant if the wireless interface name has a dash which is
encoded to \x2d.
Such an interface name is rather rare, but used i.e. when configuring
multiple wireless interfaces with `networking.wlanInterfaces`[2] to have on
interface for `wpa_supplicant` and another one for `hostapd`.
[1] https://www.freedesktop.org/software/systemd/man/systemd-escape.html
[2] https://nixos.org/nixos/options.html#networking.wlaninterfaces
Add an ExecReload command to the prosody service, to allow reloading
prosody by sending SIGHUP to the main process, for example to update
certificates without restarting the server. This is exactly how the
`prosodyctl` tool does it.
Note: Currently there is a bug which prevents mod_http from reloading the
certificates properly: https://issues.prosody.im/1216.
`collectd' might fail because of a failure in any of numerous plugins.
For example `virt' plugin sometimes fails if `collectd' is started before `libvirtd'
The default galera_new_cluster script tries to set this environment
variable using systemctl set-environment which doesn't work if the
variable is not being used in the unit file ;)
Without this line, attempting to copy and paste non-ASCII characters
will result in error messages like the following (and pasting from the
server to the client will not work):
```
CLIPBOARD clipboard_send_data_response_for_text: 823 : ERROR: clipboard_send_data_response_for_text: bad string
```
There are situations where several filesystems reside on a single encrypted LUKS
device (e.g. when using BTRFS subvolumes).
Simply generating a `boot.init.luks.devices.NAME.device` entry for each mounted
filesystem will result in an error later when evaluating the nix expression in
`hardware-configuration.nix`.
For large setups it is useful to list all databases explicit
(for example if temporary databases are also present) and store them in extra
files.
For smaller setups it is more convenient to just backup all databases at once,
because it is easy to forget to update configuration when adding/renaming
databases. pg_dumpall also has the advantage that it backups users/passwords.
As a result the module becomes easier to use because it is sufficient
in the default case to just set one option (services.postgresqlBackup.enable).
This creates a dependency cycle when used with boot.tmpOnTmpfs:
basic.target <- tmp.mount <- swap.target <- zram-init-dev0 <- basic.target
This same fix is done already for tmp.mount
Fixes https://github.com/NixOS/nixpkgs/issues/47474
- add `zramSwap.algorithm` option, which allows to change compressor
declaratively. zstd as default
- add `zramSwap.swapDevices` option, which allows to define how many zram
devices will be used as swap. Rest devices can be managed freely
- simpler floating calculations
- fix udev race condition
- some documentation changes
- replaced `/sys/block/zram*` handling with `zramctl`, because I had occasional
"Device is busy" error (looks like zram has to be configured in predefined order)
- added `memoryPercent` and `algorithm` as restart triggers. I think, it was
a bug that changing `memoryPercent` in configuration wasn't applied immediately.
- removed a bind to .swap device. While it looks natural (when swap device goes
off, so should zram device), it wasn't implemented properly. This caused problems
with swapon/swapoff:
```
$ cat /proc/swaps
Filename Type Size Used Priority
/dev/zram0 partition 8166024 0 -2
/var/swapfile file 5119996 5120 1
$ sudo swapoff -a
$ sudo swapon -a
swapon: /dev/zram0: read swap header failed
$ cat /proc/swaps
Filename Type Size Used Priority
/var/swapfile file 5119996 0 1
```
