atrakic

/*
    STRINGS
*/
Assert.Equal(expectedString, actualString);
Assert.StartsWith(expectedString, stringToCheck);
Assert.EndsWith(expectedString, stringToCheck);

// Some can also take optional params
Assert.Equal(expectedString, actualString, ignoreCase: true);
Assert.StartsWith(expectedString, stringToCheck, StringComparison.OrdinalIgnoreCase);

atrakic

What

A lot of times you are developing a web application on your own laptop or home computer and would like to demo it to the public. Most of those times you are behind a router/firewall and you don't have a public IP address. Instead of configuring routers (often not possible), this solution gives you a public URL that's reverse tunnelled via ssh to your laptop.

Because of the relaxation of the sshd setup, it's best used on a dedicated virtual machine just for this (an Amazon micro instance for example).

Requirements

atrakic

Basic Pong HTML and JavaScript Game

This is a basic implementation of the Atari Pong game, but it's missing a few things intentionally and they're left as further exploration for the reader.

Further Exploration

• Score
• When a ball goes past a paddle, the other player should score a point. Use context.fillText() to display the score to the screen

atrakic

import collections, random, sys, textwrap

# Build possibles table indexed by pair of prefix words (w1, w2)
w1 = w2 = ''
possibles = collections.defaultdict(list)
for line in sys.stdin:
    for word in line.split():
        possibles[w1, w2].append(word)
        w1, w2 = w2, word

atrakic

#!/usr/bin/env -S bash -c "docker run -p 8080:8080 -it --rm \$(docker build --progress plain -f \$0 . 2>&1 | tee /dev/stderr | grep -oP 'sha256:[0-9a-f]*')"

# syntax = docker/dockerfile:1.4.0

FROM node:20

WORKDIR /root

RUN npm install sqlite3

atrakic

I'm learning about SOPS and setting it up as my preferred mechanism for storing secrets. Here are my notes.

PGP

It’s security mechanism is that we (i.e. client) use a PUBLIC key from the receiver (i.e. server) and encode it with a random key (I’m saying nonce but it could be reused)

This varies from RSA and SSH because the server uses a PUBLIC key to identify the client.

Web of trust

Web of trust operates by still using PGP (i.e. encoding with recipient’s public key) but additionally, we can encrypt/sign the data as our own by signing it with the client’s private key.

This means the recipient will initially decrypt via our (i.e. client’s) public key (verifying the source) and then decrypting via their (i.e. server’s) private key to get the data.

atrakic

Code is clean if it can be understood easily – by everyone on the team. Clean code can be read and enhanced by a developer other than its original author. With understandability comes readability, changeability, extensibility and maintainability.

---

General rules

1. Follow standard conventions.
2. Keep it simple stupid. Simpler is always better. Reduce complexity as much as possible.
3. Boy scout rule. Leave the campground cleaner than you found it.
4. Always find root cause. Always look for the root cause of a problem.

Design rules

atrakic

#!/bin/bash

target_branch="production"
working_tree="PATH_TO_DEPLOY"

while read oldrev newrev refname
do
    branch=$(git rev-parse --symbolic --abbrev-ref $refname)
    if [ -n "$branch" ] && [ "$target_branch" == "$branch" ]; then
    

atrakic

Better SSH Authorized Keys Management

A seemingly common problem that people encounter is how to handle all of your users authorized_keys file.

People struggle over management, ensuring that users only have specific keys in the authorized_keys file or even a method for expiring keys. A centralized key management system could help provide all of this functionality with a little scripting.

One piece of functionality overlooked in OpenSSH is the AuthorizedKeysCommand configuration keyword. This configuration allows you to specify a command that will run during login to retrieve a users public key file from a remote source and perform validation just as if the authorized_keys file was local.

Here is an example directory structure for a set of users with SSH public keys that can be shared out via a web server:

atrakic

#!/bin/bash
if [ "$#" -ne 1 ]; then
    echo "Usage: $0 123.123.123.123 password"
    echo "Specify your host's LAN IP and the desired Pihole password"
    exit 1
fi

IP=$1
PASSWORD=$2