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How to use PlantUML with Markdown

PlantUML is a really awesome way to create diagrams by writing code instead of drawing and dragging visual elements. Markdown is a really nice documentation tool.

Here's how I combine the two, to create docs with embedded diagrams.

Step 0: Setup

Get the command-line PlantUML from the download page or your relevant package manager.

The below instructions describe the process for MITM'ing a target device over HTTPS using nginx. It tries to go over every aspect of intercepting traffic, including hosting a Wifi access point.

Overview

The goal is to get a target device (such as an iPhone, Wii U, or another computer) to trust our local nginx server instead of the remote trusted server. This is going to be done by importing a custom CA root certificate on the target that corresponds with the nginx server's certificate.

Client (Trusted Device) <--> MITM Server (nginx) <--> Remote (Trusted) Server

Requirements

These instructions are being performed on a PureOS machine, which is Debian based. They should also work in other environments with slight modifications

Abstract

Imagine we have n particles in our "universe". These particles have a random initial x, y, and z coordinates to begin with. Defined by Newton's law of universal gravitation, each particle attracts every other particles in this universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. As as result, these particles gain (and lose) velocities and change positions over time. The modelling of this physical mechanics is called a N-body simulation.

There currently exists many N-body simulation algorithms. Some are less advanced and highly computational costly (execution time in the order of O(N^2)) - but simple and easy to understand. Some others are more advanced and significantly more efficient (execution in the order of O(n*log(n)) - but not as simple and easy to understand. This articles focuses on the implementation aspect of the less advanced toy algorithm - for the benefit of ease o

	#!/usr/bin/env python3

	import requests
	import json
	import sys
	import os
	import socket

	# --- settings ---

	/*
	For processing data sent to Firehose by Cloudwatch Logs subscription filters.

	Cloudwatch Logs sends to Firehose records that look like this:

	{
	"messageType": "DATA_MESSAGE",
	"owner": "123456789012",
	"logGroup": "log_group_name",
	"logStream": "log_stream_name",

	# install nix (5.5 mins)
	curl https://nixos.org/nix/install \| sh

	# open a new shell to source nix
	bash

	# query available haskell compilers
	nix-env -qaP -A nixpkgs.haskell.compiler [QUERY]

	# install ghc (2.5 mins, cached binary)

	#!/usr/bin/env bash

	### Bash Environment Setup
	# http://redsymbol.net/articles/unofficial-bash-strict-mode/
	# https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html
	# set -o xtrace
	set -o errexit
	set -o errtrace
	set -o nounset
	set -o pipefail

	### JHW 2018
	import numpy as np
	import umap



	# This code from the excellent module at:
	# https://stackoverflow.com/questions/4643647/fast-prime-factorization-module

	import random

	### prerequisites
	sudo yum groupinstall "Development Tools"
	git --version
	gcc --version
	bash --version
	python --version # (system)
	sudo yum install -y openssl-devel readline-devel zlib-devel
	sudo yum update

	### install `pyenv`

	#!/bin/bash

	set -euo pipefail

	openssl req -new -text -passout pass:abcd -subj /CN=localhost -out server.req -keyout privkey.pem
	openssl rsa -in privkey.pem -passin pass:abcd -out server.key
	openssl req -x509 -in server.req -text -key server.key -out server.crt
	chmod 600 server.key
	test $(uname -s) = Linux && chown 70 server.key
	docker run -d --name postgres -e POSTGRES_HOST_AUTH_METHOD=trust -v "$(pwd)/server.crt:/var/lib/postgresql/server.crt:ro" -v "$(pwd)/server.key:/var/lib/postgresql/server.key:ro" postgres:12-alpine -c ssl=on -c ssl_cert_file=/var/lib/postgresql/server.crt -c ssl_key_file=/var/lib/postgresql/server.key