Charon needs this to include the dynamically generated
/root/.vbox-charon-client-key. (We used
users.extraUsers.root.openssh.authorizedKeys.keyFiles for this, but
that no longer works.)
Instead of the somewhat hacky script that inserted public keys
into the users' .ssh/authorized_keys files, use the AuthorizedKeysFile
configuration directive in sshd_config and generate extra key
files for each user (placed in /etc/authorized_keys.d/).
Thus
networking.interfaces = [ { name = "eth0"; ipAddress = "192.168.15.1"; } ];
can now be written as
networking.interfaces.eth0.ipAddress = "192.168.15.1";
The old notation still works though.
My main reason for adding this is the ability to turn off helpers
altogether. If you are not using any of the special protocols, keeping
them turned off is safest, and in case you do want to use them, it's
best to configure them through the new CT target for your network
topology. Perhaps some sane defaults for nixos can be examined in the
future.
This change has no impact if you don't touch the added options, so no
need to adapt.
This is meant to replace /proc/sys/net/ipv4/conf/*/rp_filter, which
only works for ipv4. Furthermore, it's nicer to handle this kind of
filtering in the firewall.
There are some more subtle differences, please see:
https://home.regit.org/netfilter-en/secure-use-of-helpers/
I chose to enable this by default (when the firewall is enabled) as
it's a good idea in general. Only people with advanced routing needs
might not want this, but I guess they don't use the nixos firewall
anyway and use a custom solution. Furthermore, the option only becomes
available in kernel 3.3+, so conservative nixos users that just stick
to the default kernel will not need to act now just yet.
So instead of:
boot.systemd.services."foo".serviceConfig =
''
StartLimitInterval=10
CPUShare=500
'';
you can say:
boot.systemd.services."foo".serviceConfig.StartLimitInterval = 10;
boot.systemd.services."foo".serviceConfig.CPUShare = 500;
This way all unit options are available and users can set/override
options in configuration.nix.
This makes it easier for systemd to track it and avoids race conditions such as
this one:
systemd[1]: PID file /run/sshd.pid not readable (yet?) after start.
systemd[1]: Failed to start SSH Daemon.
systemd[1]: Unit sshd.service entered failed state.
systemd[1]: sshd.service holdoff time over, scheduling restart.
systemd[1]: Stopping SSH Daemon...
systemd[1]: Starting SSH Daemon...
sshd[2315]: Server listening on 0.0.0.0 port 22.
sshd[2315]: Server listening on :: port 22.
sshd[2335]: error: Bind to port 22 on 0.0.0.0 failed: Address already in use.
sshd[2335]: error: Bind to port 22 on :: failed: Address already in use.
sshd[2335]: fatal: Cannot bind any address.
systemd[1]: Started SSH Daemon.
* Add group 'networkmanager' and implement polkit configuration
that allows users in this group to make persistent, system-wide
changes to NetworkManager settings.
* Add support for ModemManager. 3G modems should work out of the
box now (it does for me...). This introduces a dependency on
pkgs.modemmanager.
* Write NetworkManger config file to Nix store, and let the
daemon use it from there.
Logind sessions are more generally useful than for device ownership.
For instances, ssh logins can be put in their own session (and thus
their own cgroup).
Subtle: dhcpcd.service would call resolvconf during shutdown, which in
turn would start invalidate-nscd.service, causing the shutdown to be
cancelled. Instead, give nscd.service a proper reload action, and do
"systemctl reload --no-block nscd.service". The --no-block is
necessary to prevent that command from waiting until a timeout occurs
(bug in systemd?).
