Discover gists

Node.js Deployment

Steps to deploy a Node.js app to DigitalOcean using PM2, NGINX as a reverse proxy and an SSL from LetsEncrypt

1. Create Free AWS Account

Create free AWS Account at https://aws.amazon.com/

2. Create and Lauch an EC2 instance and SSH into machine

I would be creating a t2.medium ubuntu machine for this demo.

Solving "includer's revenge" from hxp ctf 2021 without controlling any files

The challenge

The challenge was to achieve RCE with this file:

<?php ($_GET['action'] ?? 'read' ) === 'read' ? readfile($_GET['file'] ?? 'index.php') : include_once($_GET['file'] ?? 'index.php');

Some additional hardening was applied to the php installation to make sure that previously known solutions wouldn't work (for further information read this writeup from the challenge author).

I didn't solve the challenge during the competition - here is a writeup from someone who did - but since the idea I had differed from the techniques used in the published writeups I read (and I thought it was cool :D), here is my approach.

How to mount a qcow2 disk image

This is a quick guide to mounting a qcow2 disk images on your host server. This is useful to reset passwords, edit files, or recover something without the virtual machine running.

Step 1 - Enable NBD on the Host

modprobe nbd max_part=8

Render custom blocks

$bid = 'myblock';
$block = \Drupal\block_content\Entity\BlockContent::load($bid);
$render = \Drupal::entityTypeManager()->getViewBuilder('block_content')->view($block);

Render plugin blocks

$block_manager = \Drupal::service('plugin.manager.block');

Git Submodules basic explanation

Why submodules?

In Git you can add a submodule to a repository. This is basically a repository embedded in your main repository. This can be very useful. A couple of usecases of submodules:

Separate big codebases into multiple repositories.

GMK67 manual

English manual for the ZUOYA GMK67 Mechanical Keyboard. Made from the printed version (Original).

GMK67 manual
Description

How To Work With Multiple Github Accounts on a single Machine

Let suppose I have two github accounts, https://github.com/rahul-office and https://github.com/rahul-personal. Now i want to setup my mac to easily talk to both the github accounts.

NOTE: This logic can be extended to more than two accounts also. :)

The setup can be done in 5 easy steps:

Steps:

Step 1 : Create SSH keys for all accounts
Step 2 : Add SSH keys to SSH Agent

	import UIKit

	final class CustomIntensityVisualEffectView: UIVisualEffectView {
	/// Create visual effect view with given effect and its intensity
	///
	/// - Parameters:
	/// - effect: visual effect, eg UIBlurEffect(style: .dark)
	/// - intensity: custom intensity from 0.0 (no effect) to 1.0 (full effect) using linear scale
	init(effect: UIVisualEffect, intensity: CGFloat) {
	theEffect = effect

	-ea
	-server
	-Xms512m
	-Xmx2g
	-XX:ParallelGCThreads=8
	-XX:PermSize=350m
	-XX:MaxPermSize=350m
	-XX:ReservedCodeCacheSize=240m
	-XX:LargePageSizeInBytes=256m
	-XX:+UseConcMarkSweepGC

	David Fowler 🇧🇧🇺🇸💉💉💉 on Twitter: "If you are queuing background jobs/work items today in your .NET applications, how are you doing it and what are you using it for? #dotnet #aspnetcore" / Twitter
	https://twitter.com/davidfowl/status/1442566223099666436

	Background tasks with hosted services in ASP.NET Core \| Microsoft Docs
	https://docs.microsoft.com/en-us/aspnet/core/fundamentals/host/hosted-services?view=aspnetcore-6.0&tabs=visual-studio

	Messaging that just works — RabbitMQ
	https://www.rabbitmq.com/

	.NET/C# Client API Guide — RabbitMQ