Matthias Vandermaesen netsensei

Intro

Digital ocean Linux introduction series
- An intro to the linux terminal https://www.digitalocean.com/community/tutorials/an-introduction-to-the-linux-terminal
- Linux navigation and file management https://www.digitalocean.com/community/tutorials/basic-linux-navigation-and-file-management
- An intro to linux permissions https://www.digitalocean.com/community/tutorials/an-introduction-to-linux-permissions
- An intro to linux I/O redirection https://www.digitalocean.com/community/tutorials/an-introduction-to-linux-i-o-redirection
Command line for beginners https://www.freecodecamp.org/news/command-line-for-beginners/
Bash scripting for beginners https://www.freecodecamp.org/news/bash-scripting-tutorial-linux-shell-script-and-command-line-for-beginners/

How to screen

Create a new screen session:

screen -S session_name

Detach from your screen session:

Installing pqsl, pg_dump and pg_restore via hombrew

These instructions allow you to intall psql, pg_dump & pg_restore without a full installation of postgresql.

First, install libpq via homebrew

brew doctor
brew update
brew install libpq

Installation and initial setup of Elasticsearch on Fedora

Installation of ES 6.8

$ sudo dnf install java-latest-openjdk
$ sudo rpm --import https://artifacts.elastic.co/GPG-KEY-elasticsearch
$ cat <<EOF | sudo tee /etc/yum.repos.d/elasticsearch.repo
[elasticsearch-6.x]
name=Elasticsearch repository for 6.x packages

Installation and initial setup of PostgreSQL for local use

Step 1: Installation of PostgreSQL

Add the YUM repo to your host:

$ sudo dnf install https://download.postgresql.org/pub/repos/yum/reporpms/F-37-x86_64/pgdg-fedora-repo-latest.noarch.rpm

Setuping PI-Hole FTL DNS on a local network

pihole comes with it's own lightweight DNS server called FTL. It's geared towards easy of use. Even so, setting up this feature can be hard. Here are some lessons I've learned.

In this example:

Your network is setup on 192.168.1.0/24
192.168.1.1 is your DHCP server and IP gateway. (usually your router)
192.168.1.254 is the host running pi-hole

Comparing two files each containing a single column dataset with Perl

Warning! One liners such as these are basically hacks. Please look into the comm program which is part of GNU Coreutils. It basically does all of this without any of the complexity below. See: https://www.gnu.org/software/coreutils/manual/html_node/comm-invocation.html

You have 2 text files, each containing rows of data each having 1 column (e.g. e-mail address, uuids, names, md5 hashes,...). You want to very quickly compare those, spending the least amount of time and energy, looking for ...

... rows both files have in common (intersection)
... rows which are in file A but not in file B.
... rows which are in file B but not in file A.

	#!/bin/bash
	DIR=$1

	if [[ ! -d $DIR ]];then
	echo "${DIR} does not exist."
	exit 1
	fi

	BASENAME=$(basename $DIR)
	UPDIR=$(cd $DIR/.. && pwd)

	#!/usr/bin/python3
	#
	# run it:
	# STIBKEY=<apikey> ./stib.py

	import os
	import requests
	import json
	import datetime
	from datetime import timedelta

	flowchart LR
	W((World)) --- TR
	TR --- KC(Keycloak)
	BB --- KC
	subgraph Nomad
	TR(Traefik proxy) --- BB
	BB(Biblio backend) --- NATS{NATS}
	NATS --- JB{JMS bridge}
	JB --- F(Fedora repository)
	NATS --- IDX(Indexer service)