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Multiple python versions

Reasoning and use cases

There are often scenarios when we would need to install multiple versions of python.

On on our development machine, we might want to work on many projects, some using different python versions, or maybe we're working on a package that we want to support on multiple

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Making a UEFI bootable iPXE USB drive

Build the UEFI executable for iPXE

# First we'll clone iPXE
$ git clone git://git.ipxe.org/ipxe.git
# Go into the src directory of the cloned git repo
$ cd ipxe/src
# Compile the UEFI iPXE executable

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Run Docker (without Docker Desktop) on MacOS with Apple Silicon (M1/M2/...)

Docker Desktop requires an expensive license for commercial use: https://www.docker.com/pricing/faq/

# Install minikube
brew install minikube

# Install Docker CLI
brew install docker

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#!python


class CircularBuffer(object):

    def __init__(self, max_size=10):
        """Initialize the CircularBuffer with a max_size if set, otherwise
        max_size will elementsdefault to 10"""
        self.buffer = [None] * max_size
        self.head = 0

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Installing ChromeOS Flex (hardware accelerated) on QEMU for Windows

A word of warning. This will be slow and buggy. Do not attempt to use this as a daily driver.

Requirements:

• Windows 10 or 11 (x64)

Download Files:

• Download QEMU
• Download ChromeOS Flex (remember to download the file; do NOT use Chromebook Recovery Utility)

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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

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Install Alpine Linux Via Minirootfs Archive.

Prerequisites.

• Any live usb bootable.
• Alpine Linux minirootfs archive, we can get it here. We can choose alpine-minirootfs-3.20.2-x86_64.tar.gz.
• Some partitions, for root system (/), efi (if you have uefi machine) and swap (optional).
• Basic commandline knowledge.

Steps.

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Ubuntu 24.04 Firefox snap replacement

I need a proper Firefox installation and not the snap version. The snap version does not work properly with Smart Cards. Although it seems to be possible to get it to work with smart cards it is extremely difficult and I don't care to try and make it work. This is not a tutorial on how to get your PIV or CAC to work. Also snaps suck. Canonical will heopfully abandon snaps in the future.

Remove Snap Firefox

sudo snap disable firefox
sudo snap remove --purge firefox
error: cannot perform the following tasks:
- Remove data for snap "firefox" (1943) (unlinkat /var/snap/firefox/common/host-hunspell/en_ZA.dic: read-only file system)

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Setting up Qemu with a tap interface

There are two parts to networking within QEMU:

• The virtual network device that is provided to the guest (e.g. a PCI network card).
• The network backend that interacts with the emulated NIC (e.g. puts packets onto the host's network).

Example: User mode network

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import paramiko
k = paramiko.RSAKey.from_private_key_file("/Users/whatever/Downloads/mykey.pem")
c = paramiko.SSHClient()
c.set_missing_host_key_policy(paramiko.AutoAddPolicy())
print "connecting"
c.connect( hostname = "www.acme.com", username = "ubuntu", pkey = k )
print "connected"
commands = [ "/home/ubuntu/firstscript.sh", "/home/ubuntu/secondscript.sh" ]
for command in commands:
	print "Executing {}".format( command )