It was lacking the dbus configuration to bind to
org.freedesktop.DisplayManager, and it was passing fixed TTY/display
numbers to the X server (see 9be012f0d4).
Using the example before this commit resulted in the following error:
```
error: value is a string while a list was expected, at /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/services/misc/nix-daemon.nix:349:37
```
The old etcd port 4001 is no longer enabled by default in etcd 3.
The new port is 2379 and is officially assigned by IANA.
There were still some services left that expect etcd on port 4001 by default.
This changes the default to 2379 everywhere.
It should not cause problems for users as the etcd by nix does listen on the new port only by default anyway.
The current default probe config uses the unwrapped fping binary, which
leads to an error because fping must be executed with elevated
permissions.
I fixed this by changing the path to the default binary to the
setuid-wrapped version.
This commit includes two changes:
1. A new `extraConfig` option to allow administrators to set any
vsftpd configuration option that isn't directly supported by this
derivation.
2. Correctly set the `anon_root` vsftpd option to `anonymousUserHome`
In the prestart config of the smokeping service, smokeping is executed
initially. This happens as the user root and writes some files to
$smokepingHome, which can't be overwritten by the smokeping user. This
gives an error message.
I fixed this by moving the chown step after the initial smokeping runs,
so that it also affects the generated files.
The matrix-synapse user has `createHome = true;` which runs before the
`preStart` script, so the home directory will always exist and the block
will never execute.
Also don't include default path to keys in the configuration file,
because synapse will choke if it tries to open them before they
exist (even with `--generate-keys`).
