FlakM

Setting up qemu VM using nix flakes

Did you know that it is rather easy to setup a VM to test your NixOs configuration?

Create simple flake:

# flake.nix
{
  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";

Eriner

.compose-form__publish-button-wrapper .button--block {
  font-size: 0px;
}

.compose-form__publish-button-wrapper .button--block::after {
  content: "Toot!";
  font-size: 15px;
  vertical-align: middle;
  color: #fff;
}

SCOTT-HAMILTON

#! /usr/bin/env nix-shell
#! nix-shell -i sh -p coreutils findutils gnused ripgrep strace
# Usage ./get-command-nix-deps.sh ./script.sh 10s
timeout "$2" strace -qqfe execve sh -c "$1" 2>&1 >/dev/null | \
  rg '(/nix/store|/run/current-system/sw/bin)' | \
  sed -E 's=.*execve\("(\/.*)", \[.*=\1=g' | \
  xargs readlink -f | sort -u | \
  sed -E 's=/nix/store/[0-9a-z]*-(.*)-(.*)/.*/.*=\1 (\2)=g' | sort -u

nitred

About

• I faced bandwidth issues between a WG Peer and a WG server. Download bandwidth when downloading from WG Server to WG peer was reduced significantly and upload bandwidth was practically non existent.
• I found a few reddit posts that said that we need to choose the right MTU. So I wrote a script to find an optimal MTU.
• Ideally I would have liked to have run all possible MTU configurations for both WG Server and WG Peer but for simplicity I choose to fix the WG Server to the original 1420 MTU and tried all MTUs from 1280 to 1500 for the WG Peer.

Testing

• On WG server, I started an iperf3 server
• On WG peer, I wrote a script that does the following:
  • wg-quick down wg0
• Edit MTU in the /etc/wireguard/wg0.conf file

lheckemann

{ pkgsPath ? <nixpkgs> }:
let
  pkgs = import pkgsPath {};
  pkgsAarch64 = import pkgsPath { system = "aarch64-linux"; };

  iso = (pkgsAarch64.nixos {
    imports = [ (pkgsPath + "/nixos/modules/installer/cd-dvd/installation-cd-base.nix") ];
    users.users.root.openssh.authorizedKeys.keyFiles = [(builtins.fetchurl https://github.com/lheckemann.keys)];
  }).config.system.build.isoImage;

TheSirC

{ lib, config, pkgs, ... }:

with lib;

{
  options.v4l2 = mkEnableOption "Enable the confguration to use the reflex as a webcam";
  config = mkIf config.v4l2 {
    # 20.03: v4l2loopback 0.12.5 is required for kernel >= 5.5
    # https://github.com/umlaeute/v4l2loopback/issues/257

walkermalling

Setting up NixOs with LUKS encrypted root

Here are my working notes on getting a system up and running.

WARNING: You can run into a hidden problem that will prevent a correct partition setup and /etc/nixos/configuration.nix from working: if you are setting up a UEFI system, then you need to make sure you boot into the NixOS installation from the UEFI partition of the bootable media. You may have to enter your BIOS boot selection menu to verify this. For example, if you setup a NixOS installer image on a flash drive, your BIOS menu may display several boot options from that flash drive: choose the one explicitly labeled with “UEFI”.

References

I used these resources:

Xe

NixOps Deployment of a Docker Container

Install NixOps

If using NixOS:

$ nix-env -iA nixos.nixops

MCJack123

#!/usr/bin/env python
from sys import argv, stdout
from os import system, remove, path
from urlparse import urlparse
import re
import dfu
import ssl
import math
import json
import getopt

edrex

Recipes

kmsgrab capture with ffmpeg

sudo LIBVA_DRIVER_NAME=iHD ffmpeg -crtc_id 69  -framerate 60 -f kmsgrab -i - -vaapi_device /dev/dri/renderD128 -filter:v hwmap,scale_vaapi=w=1920:h=1200:format=nv12 -c:v h264_vaapi -profile:v constrained_baseline -level:v 3.1 -b:v 20000k test.mp4

LIBVA_DRIVER_NAME=iHD ffmpeg -device /dev/dri/card0 -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' -c:v h264_vaapi -vstats output.mp4