Travis Johnson bashtheshell

Lima Cheatsheet for macOS

I stumbled on an incredible open source solution, Lima. In some ways, it has some of Hashicorp's Vagrant's resemblance, but in my opinion, it's so much superior in many ways as it doesn't use external dependencies such as Oracle's VirtualBox.

If you're used to docker on the command line but wanted to play with VMs rather than containers, then this is for you! No need to fuss with cloud-init as a user account (using your existing username in whoami) with a proper home directory would be auto-generated for you with full passwordless sudo privilege. SSH access to the VMs from the host is seamlessly integrated as well.

This quick guide is for those who need to set up virtual machines with modern Linux OSes (only few selected OSes are best supported) from scratch using only the command line. You can have a VM up and running within minutes from absolutely nothing.

NOTE: This was last tested using:

`lima

Workaround for lack of native snapshot feature in UTM

This was written when latest release version of UTM was v4.5.3.

NOTE: Snapshots using qemu-img is not supported for macOS VMs due to .img image format as other pre-configured non-macOS VMs are using .qcow2 as the storage backend, which is well-supported.

How to Use Raspberry Pi's `rpi-imager --cli` Command on macOS

With the modern rpi-imager tool, we can automate the imaging process for the Raspberry Pi computer board and make the process extremely painless for us each time we need to re-image.

The official Raspberry Pi's rpi-imager's tool (which can be installed from https://www.raspberrypi.com/software/) contains a command-line option that's not widely documented anywhere at the time of this writing (v1.7.5 was the latest release).

The best official documentation I can possibly find on Raspberry Pi Imager did not cover the command-line option.

As a result, I'll only cover the command-line option for macOS here as it's my daily driver.

HandBrake Automated Conversion - Whole DVD to Individual M4V Chapter Files

As the title suggested, HandBrake can be used to extract chapters from the DVD movie (assuming only one title exists on DVD) and write them to the data storage in M4V format using HandBrake's default preset, Fast 1080p30.

By default, HandBrake would copy the entire DVD and write them to a single M4V file. I've developed a wrapper script, leveraging the HandBrakeCLI command to perform the automation of reading a specific chapter from the DVD and writing it to an .m4v file.

The files would be written in a directory named after the filename of a required chapter markers file, which

How to Create Clover Bootloader USB on macOS (for PCIe NVMe SSD booting on Legacy BIOS system):

SUMMARY:

If you are a macOS user like me, and you want to create a Clover Bootloader USB on it just so that you can boot up the operating systems that are installed on PCIe NVMe SSDs on your archaic hardware using legacy BIOS? Then you've come to the right place. You may be a homelabber like myself wanting to boot up the hypervisor (e.g. Proxmox).

I've spent numerous hours, searching for a clear step-to-step guide on this, and apparently there isn't an easily-searchable one for macOS users at the time of this writing. Fortunately for us, the Clover project, hosted on GitHub, has a convenient package for us to create a bootloader USB. This project is also hosted on SourceForge.

DOWNLOADING CLOVER:

Install Slack app in User's Applications Directory - macOS

Background

This work was inspired by the challenges I encountered in the workplace. I manage several macOS remotely, and one of the biggest pains is that our users aren't administrators on those machines. Thus, they aren't able to dismiss the Squirrel Update prompts on their own, which was a productivity hindrance.

Initially as a fun side-project to satisfy my curiosity, I came up with a solution to mitigate this by having the Slack app, which was already installed in the main /Applications directory, automatically update itself as soon as the Launch Daemon script fetches a new update from slack.com. The script would notify all users actively using Slack that the app would restart itself in several seconds.

Admittedly, the above solution wasn't organic and understandably it can be a grave security concern for some. The only upside of

Python3 Virtual Environment Cheat Sheet:

Oftentimes, I'd forget how to set up a quick virtual environment (virtualenv) with Python3 when I'd find myself working on a new Python script after months of inactivity.

Before running the command below, it's assumed you have Python 3 already installed and you're in a new directory. In this example, we'll use project_dir as a new directory which is located in the current user's home directory.

mkdir ~/project_dir
cd ~/project_dir
python3 -m venv venv

Videotelephony Ring Trigger

Purpose

The ultimate goal of this "ring trigger" guide is to test the videotelephony SIP-based client to see if it is actively listening on local socket. The client should ring continuously upon command execution. The tool used in this guide is simply a preexisting SIPp command, and we're going to take a narrow focus on only using the SIP INVITE request rather than the entire SIP handshake sequence.

Disclaimer: All information and software available on this guide are for educational purposes only. Use these at your own discretion, the author cannot be held responsible for any damages caused. Usage of all tools on this guide for attacking targets without prior mutual consent is illegal. It is the end user’s responsibility to obey all applicable local, state and federal laws. The author assumes no liability and is not responsible for any misuse or damage caused by this guide.

	#!/usr/bin/env python3

	# The purpose of this program is to only slightly modify and rearrange all 'A-INPUT' arguments, that may be manually written to the `iptables`'s `rules.v4`
	# file, in the order that the `iptables -S` command uses. This would allow one to see less lines when using `diff` command to compare
	# the newly-translated output from this program with `iptables -S` output. Ideally, you should not find any '-A INPUT' in the `diff` output. Otherwise, there
	# may have been a bug with the program (e.g. some strings elude the regular expression pattern). Please remember that lines beginning with comment ('#')
	# are ignored.

	# USAGE:
	# You can either give it a file as its argument or pass a file to the program using STDIN. Here are few ways: