Filipe Veloso Rovel

Reset Forgotten Raspberry Pi Password

Remove SD Card

The first step is to turn off the Raspberry so you can remove the memory card without worry.

If the Raspberry Pi is not connected to a screen, the only way to turn it off is to unplug it. Otherwise, you can go through the GUI to turn it off properly, via the menu, before unplugging it.

Once the Raspberry Pi is turned off, you can insert the card into your computer and go to the next step.

How to Change Open Files Limit on OS X and macOS

To check the current limits on your Mac OS X system, run in terminal:

launchctl limit maxfiles
ulimit -a

Steps

Generate your keys

Prereqs

gpg

Create your keys with your email.

Execute following commands:

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

-E: will describe the underlaying queries of the \ commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

	#!/bin/bash

	# Ubuntu 24.04 Server Hardening Script

	set -euo pipefail
	IFS=$'\n\t'

	# --- Constants ---
	REQUIRED_OS="Ubuntu"
	REQUIRED_VERSION="24.04"

	version: '3'

	services:
	redis:
	image: redis:5.0.0
	container_name: master
	ports:
	- "6379:6379"
	networks:
	- redis-replication

	ruby '2.7.1'

	gem 'rails', github: 'rails/rails'
	gem 'tzinfo-data', '>= 1.2016.7' # Don't rely on OSX/Linux timezone data

	# Action Text
	gem 'actiontext', github: 'basecamp/actiontext', ref: 'okra'
	gem 'okra', github: 'basecamp/okra'

	# Drivers

	name: Elixir CI

	on:
	push:
	branches: [ master ]
	pull_request:
	branches: [ master ]

	env:
	MIX_ENV: test

	{
	"$schema": "https://aka.ms/terminal-profiles-schema",
	"defaultProfile": "{09dc5eef-6840-4050-ae69-21e55e6a2e62}",
	"initialRows": 30,
	"initialCols": 120,
	"alwaysShowTabs": true,
	"showTerminalTitleInTitlebar": true,
	"experimental_showTabsInTitlebar": true,
	"profiles": [
	{

	#!/bin/bash
	REGIONS=$(aws ec2 describe-regions --output json \| awk -F'"' '/"RegionName":/ { print $4 }')

	for Region in $REGIONS
	do
	Snaps=$(aws rds describe-db-snapshots --output json --region ${Region} \| awk -F'"' '/"DBSnapshotIdentifier":/ {print $4 }')
	if [ -z "$Snaps" ]; then
	echo "No snapshots found in $Region"
	echo "======================================================="
	else