Rock coaxial

☁️ How I got off the cloud and migrated everything from AWS to a VPS in Hetzner

This is an opinionated handbook on how I migrated all my Rails apps off the cloud and into VPS.

This is how I manage real production loads for my Rails apps. It assumes:

Rails 7+
Ruby 3+
PostgreSQL
Ubuntu Server 24.04
Capistrano, Puma, Nginx

Most of the time, applications won't pin the certificate. Running mitmproxy and passing all Android traffic through it is as simple as adb connect <IP> && adb shell settings put global http_proxy <mitmproxy host>:<mitmproxy port> (or use Android's UI)

Some applications, however, pin the certificate and will refuse to do any network calls if using mitmproxy.

Luckily, Frida is here!

This assumes Android x86 is running in a VM, that you are a developer in Android (tap the build version enough times), adb debugging is enabled, and that android tools are installed on the host.

start mitmproxy on host
visit mitm.it on the target (after setting the proxy) and install the spoofed cert

Using a simple IR receiver such as IR5040 or TSOPxxxxx and a Raspberry Pi running LibreELEC + Kodi

Enable `lirc` in Kodi

Edit the file at /flash/config:

mount -o remount,rw /flash
vi /flash/config
append device_tree_overlay=lirc-rpi
mount -o remount,ro /flash

Connect the receiver

Useful resources for Bash witchcraft

How to detect if a command is available (or `hash` vs `command -v` vs `type`)

https://stackoverflow.com/questions/592620/check-if-a-program-exists-from-a-bash-script#677212

Using arrays

http://www.tldp.org/LDP/abs/html/arrays.html

Testing for files

http://tldp.org/LDP/abs/html/fto.html

How to create a LXD Container with your ssh key in it (and with ssh server in the container)

Create a brand new ed25519 key pair

ssh-keygen -o -a 100 -t ed25519

Get the pub key and put the result in your lxd default profile

cat ~/.ssh/ed25519.pub
lxc profile edit default

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

Effective Engineer - Notes

By Edmond Lau
Highly Recommended 👍
http://www.theeffectiveengineer.com/

What's an Effective Engineer?

backup services research

I googled around, especially with site:news.ycombinator.com for backup recommendations. Here are notes on the top hits.

tarsnap

http://www.tarsnap.com/

by prolific HN member; focus on encryption and deduplication

Anonymising PDFs

PDF metadata

Metadata in PDF files can be stored in at least two places:

the Info Dictionary, a limited set of key/value pairs
XMP packets, which contain RDF statements expressed as XML

	# Reconstructed via infocmp from file: /lib/terminfo/t/tmux-256color
	# Create a similar file with `infocmp -x tmux-256color > tmux-256color
	# Import to target system with `tic -x xterm-256color (or whatever name you gave this file)
	# From https://unix.stackexchange.com/questions/574669
	tmux-256color\|tmux with 256 colors,
	OTbs, OTpt, am, hs, km, mir, msgr, xenl, AX, G0,
	colors#0x100, cols#80, it#8, lines#24, pairs#0x10000, U8#1,
	acsc=++\,\,--..00``aaffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{\|\|}}~~,
	bel=^G, blink=\E[5m, bold=\E[1m, cbt=\E[Z, civis=\E[?25l,
	clear=\E[H\E[J, cnorm=\E[34h\E[?25h, cr=\r,

	---
	# This has been tested with ansible 1.3 with these commands:
	# ansible-playbook -i hosts ansible_conditionals_examples.yaml --extra-vars="hosts=myhosts isFirstRun=false"
	# ansible-playbook -i hosts ansible_conditionals_examples.yaml --extra-vars="hosts=myhosts isFirstRun=true"
	# ansible-playbook -i hosts ansible_conditionals_examples.yaml --extra-vars="hosts=myhosts"
	# NB: The type of the variable is crucial!

	- name: Ansible Conditionals Examples
	hosts: $hosts
	vars_files: