OvertCoffee

How to resize a qcow2 disk image on Linux

This example takes olddisk.qcow2 and resizes it into newdisk.qcow2, extending one of the guest's partitions to fill the extra space.

1. qcow2 format

1.1. Verify the filesystems of `olddisk.qcow2`

Based on https://github.com/itead/Sonoff_Devices_DIY_Tools/blob/master/SONOFF%20DIY%20MODE%20Protocol%20Doc%20v2.0%20Doc.pdf

NB: This document describles a 'Old-School' way of using Yubikey with SSH

Modern OpenSSH has native support for FIDO Authentication. Its much simpler and should also be more stable with less moving parts. OpenSSH also now has support for signing arbitary files witch can be used as replacement of gnupg. Git also supports signing commits/tags with ssh keys.

Pros of FIDO

Simpler stack / less moving parts
Works directly with ssh, ssh-add and ssh-keygen on most computers
Simpler
Private key can never leave the FIDO device

Cons of FIDO

YubiKey 4 series GPG and SSH setup guide

Written for fairly adept technical users, preferably of Debian GNU/Linux, not for absolute beginners.

You'll probably be working with a single smartcard, so you'll want only one primary key (1. Sign & Certify) and two associated subkeys (2. Encrypt, 3. Authenticate). I've published a Bash function which automates this slightly special key generation process.

Use curl to get the JSON response for the latest release
Use grep to find the line containing file URL
Use cut and tr to extract the URL
Use wget to download it

curl -s https://api.github.com/repos/jgm/pandoc/releases/latest \
| grep "browser_download_url.*deb" \
| cut -d : -f 2,3 \
| tr -d \" \

	#!/bin/bash
	#
	# arp-monitor, an ARP tables monitor
	# inspired by https://gist.github.com/maugern/30ace2764aafc683a802de2ed82f91af
	#
	# This script is intended to start on launch and run on an always connected device on a network (eg: server).
	# It scans the network with 'arp -a' and sends a notification webhook whenever recognizes a new mac address on the network.
	#
	# For auto-run on login you can rename the script to a .command and add it to your Login items on Mac OS or
	# modify the script to remove the loop and take a look at crontab


	version: "3.3"

	services:
	################################################
	#### Traefik Proxy Setup #####
	###############################################
	traefik:
	image: traefik:v2.0
	restart: always

	# ------------------------------------------------
	# Config files are located in /etc/wireguard/wg0
	# ------------------------------------------------

	# ---------- Server Config ----------
	[Interface]
	Address = 10.10.0.1/24 # IPV4 CIDR
	Address = fd86:ea04:1111::1/64 # IPV6 CIDR
	PostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE; ip6tables -A FORWARD -i wg0 -j ACCEPT; ip6tables -t nat -A POSTROUTING -o eth0 -j MASQUERADE # Add forwarding when VPN is started
	PostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE; ip6tables -D FORWARD -i wg0 -j ACCEPT; ip6tables -t nat -D POSTROUTING -o eth0 -j MASQUERADE # Remove forwarding when VPN is shutdown

	#!/usr/bin/env python

	import os
	import re
	import subprocess
	from influxdb import InfluxDBClient

	from datetime import datetime
	import time

	Install WireGuard via whatever package manager you use. For me, I use apt.

	$ sudo add-apt-repository ppa:wireguard/wireguard
	$ sudo apt-get update
	$ sudo apt-get install wireguard

	MacOS
	$ brew install wireguard-tools

	Generate key your key pairs. The key pairs are just that, key pairs. They can be