Missing config file "default-config.json" on NixOs

[Axis-xzr]

Hello i recently tried to install opensnitch on NixOs following the wiki ( https://wiki.nixos.org/wiki/OpenSnitch ).

I tried to put everything as clearly as i could in chronologicall manner, thank you in advance for taking the time to read this.

Context:
At first i didn't have issues while following the documentation and creating rules the problem came when i tried to modify preferences.

Installation settings:
Opensnitch and opensnitch-ui are installed via the nix package repositary declaratively.

My nix configuration use the following settings:

• it is a module who is being imported into a flake
• the unstable branch of nix package is used
• no build error while updating flake.lock and rebuilding the flake afterward
• home manager is not used

# nix module 
{ config, pkgs, lib, ... }:
  
  {
  environment.systemPackages = [
  pkgs.unstable.opensnitch-ui
  ];
  
  #services.opensnitch-ui.enable = true;
  
  services = {
     opensnitch =
     { enable = true;
       package = pkgs.unstable.opensnitch;
       #settings.Server.Address = "unix:///run/user/1000/opensnitch/osui.sock";
       #settings.Firewall = "nftables";
     };
  };
 
}

Current issues:

Config file doesn't seem to be created properly in the right place while file concerning rules and system-fw.json are:
"/etc/opensnitchd/default-config.json" opensnitchd directory is present but config file is missing.

When i was able to start opensnitch with sudo permission which was the only way to connect to the socket i had error at the bottom of the preference gui displaying "unable to write in "/etc/opensnitchd/default-config.json" read only permission" i think it was i didn't take screenshot.

After some modification i made through the gui to the socket following the documentation i m unable to start the gui anymore due to a typo error i made which will show up in the following debug log (nix instead of unix) .

Loaded network aliases from /nix/store/yazc4a5ppg7k25zs5mccygi7hhyj4jpw-opensnitch-ui-1.8.0/lib/python3.13/site-packages/opensnitch/utils/network_aliases/network_aliases.json
qt.sql.qsqldatabase: QSqlDatabase requires a QCoreApplication
qt.sql.qsqldatabase: QSqlDatabase requires a QCoreApplication
qt.sql.qsqldatabase: QSqlDatabase requires a QCoreApplication
qt.sql.qsqldatabase: QSqlDatabase requires a QCoreApplication
	 ~ OpenSnitch GUI - 1.8.0 ~
	protobuf: 6.33.2 - grpc: 1.76.0
-------------------------------------------------- 

QT_AUTO_SCREEN_SCALE_FACTOR: True
gRPC Max Message Length: 4MiB
                  Bytes: 4194304
[server] addr: nix:///run/user/1000/opensnitch/osui.sock
is new file, or IN MEMORY, setting initial schema version
setting schema version to: 3
setting schema version to: 3
Setting journal_mode:  OFF
Setting DB memory optimizations
schema version: 3
db schema is up to date
actions.__init__ exception: [Errno 17] File exists: '/root/.config//opensnitch/actions/'
actions.__init__ exception: [Errno 17] File exists: '/root/.config//opensnitch/actions/'
Loading translations: /nix/store/yazc4a5ppg7k25zs5mccygi7hhyj4jpw-opensnitch-ui-1.8.0/lib/python3.13/site-packages/opensnitch/utils/../i18n locale: en_US
[WARNING] DesktopNotifications not available. Try installing the package python3-notify2
org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Notifications was not provided by any .service files
using IPASN DB: /nix/store/si002kv0gl7zk544ln458qkbagv1vdmj-python3.13-pyasn-1.6.2/lib/python3.13/site-packages/pyasn/data/ipasn_20140513_v12.dat.gz
actions.__init__ exception: [Errno 17] File exists: '/root/.config//opensnitch/actions/'
[WARNING] DesktopNotifications not available. Try installing the package python3-notify2
org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Notifications was not provided by any .service files
[server] using address: nix:///run/user/1000/opensnitch/osui.sock auth type: simple
WARNING: All log messages before absl::InitializeLog() is called are written to STDERR
E0000 00:00:1768581063.956321   14529 add_port.cc:83] Failed to add port to server: getaddrinfo("nix:///run/user/1000/opensnitch/osui.sock"): Servname not supported for ai_socktype (-8)
Failed to bind to address nix:///run/user/1000/opensnitch/osui.sock; set GRPC_VERBOSITY=debug environment variable to see detailed error message.
qt.sql.qsqldatabase: QSqlDatabasePrivate::removeDatabase: connection 'db' is still in use, all queries will cease to work.

What i tried

• Using the command opensnitch-ui --debug without sudo make it possible to start the ui which seems to load a default config file probably from the nix store which avoid the error related to the socket but there is no node, here the following debug log:

Loaded network aliases from /nix/store/yazc4a5ppg7k25zs5mccygi7hhyj4jpw-opensnitch-ui-1.8.0/lib/python3.13/site-packages/opensnitch/utils/network_aliases/network_aliases.json
qt.sql.qsqldatabase: QSqlDatabase requires a QCoreApplication
qt.sql.qsqldatabase: QSqlDatabase requires a QCoreApplication
qt.sql.qsqldatabase: QSqlDatabase requires a QCoreApplication
qt.sql.qsqldatabase: QSqlDatabase requires a QCoreApplication
	 ~ OpenSnitch GUI - 1.8.0 ~
	protobuf: 6.33.2 - grpc: 1.76.0
-------------------------------------------------- 

QT_AUTO_SCREEN_SCALE_FACTOR: True
gRPC Max Message Length: 4MiB
                  Bytes: 4194304
[server] addr: unix:///tmp/osui.sock
is new file, or IN MEMORY, setting initial schema version
setting schema version to: 3
setting schema version to: 3
Setting journal_mode:  OFF
Setting DB memory optimizations
schema version: 3
db schema is up to date
actions.__init__ exception: [Errno 17] File exists: '/home/pcfix/.config//opensnitch/actions/'
actions.__init__ exception: [Errno 17] File exists: '/home/pcfix/.config//opensnitch/actions/'
Loading translations: /nix/store/yazc4a5ppg7k25zs5mccygi7hhyj4jpw-opensnitch-ui-1.8.0/lib/python3.13/site-packages/opensnitch/utils/../i18n locale: en_US
using IPASN DB: /nix/store/si002kv0gl7zk544ln458qkbagv1vdmj-python3.13-pyasn-1.6.2/lib/python3.13/site-packages/pyasn/data/ipasn_20140513_v12.dat.gz
actions.__init__ exception: [Errno 17] File exists: '/home/pcfix/.config//opensnitch/actions/'
[server] using address: unix:///tmp/osui.sock auth type: simple
qt.qpa.services: Failed to register with host portal QDBusError("org.freedesktop.portal.Error.Failed", "Could not register app ID: Connection already associated with an application ID")

• i tried to scan the partion for all "default-config.json" without finding the one holding the string with the typo error.
• i tried to add the line ( settings.Server.Address = "unix:///run/user/1000/opensnitch/osui.sock";) to override the current settings but without effect you can see it commented out in the nix config modul.

Right now i m quite confuse as to what is happening since when started with sudo the following string with typo "nix:///run/user/1000/opensnitch/osui.sock" is pulled from a file somewhere but i failed to identify the location or the file containing it.

[gustavo-iniguez-goya]

hi @Axis-xzr !

I don't use nix so I can't help you with why the config file is not created.

Regarding the GUI: remove or edit the file /home/pcfix/.config/opensnitch/settings.conf, and change the server address to match what's configured in default-config.json.

Alternatively, you can launch the GUI to listen on the given address: opensnitch-ui --socket unix:///run/user/1000/opensnitch/osui.sock

[Axis-xzr]

Thank you for your answer, following that i managed to correct the typo error and now i can start the gui again.

I had to use the opensnitch-ui --socket unix:///run/user/1000/opensnitch/osui.sock to solve since settings.conf didn't have an impact on socket configuration due nix overriding some settings.

I also found where the configuration file was pulled from with the help of Gnome Systeme Monitor which point to a file inside the nix store which append a path to the binary pointing to the config file to use.
/nix/store/bqnkw6dj8wg4lcyn1wd807garfjy3ssj-opensnitch-1.8.0/bin/opensnitchd --config-file /nix/store/7g0c6bsy9s8lajb0aamp7yqjrm19j4k5-default-config.json

Now i still need to understand what is happening with nix setting up things where they shouldn't.