Quick Access to my selection Last Update: 2022-10-24 09:36:42 Ireland Time / 2022-10-24 01:36:42 PDT-0700 Unix epoch: 1666600602
Cloud Computing Operations Engineering/DevOps/SRE Engineering My Books
Provisioning AWS EC2 Instances with Ansible and Automating Apache deployment with or without using Ansible Dynamic Inventory from Ubuntu 20.04 LTS
Using Ansible in Ubuntu 20.04 LTS to provision to Amazon, and use the Dynamic Inventory (or my own Python 3 code, and alternative Bash code) to create different inventories per group, so you can provision Apache2 in your desired group of instances only.
Published: 2021-Dec Views: 2,857 views
Migrating my 11 years Amazon AWS account services (Postmortem Analysis)
Why I migrated my Services out of Amazon AWS, how I did, the problems I had and the mistakes I did.
Published: 2021-Nov Views: 2,368 views
Upgrading Amazon AWS EC2 Ubuntu 18.04 LTS to Ubuntu 20.04 LTS
Upgrading Amazon EC2 Instance with LAMP from Ubuntu Linux 18.04 LTS to version 20.04 LTS.
Published: 2021-June Views: 2,029 views
How to recover access to your Amazon AWS EC2 instance if you loss your Private Key for SSH
Procedure to get access to an Amazon AWS EC2 Instance and its Data, after you have lost your SSH Private Key and access to the instances using that Key pair.
Published: 2020-Sept Views: 5,283 views
Benchmarking Google Cloud Compute Engine (2015)
The analysis I did from Google Compute Engine, in my project CMIPS, when google launched their GCE in beta.
Paul Nash wrote me and I helped all the Cloud Team to fix some problems. :)
This analysis is a bit old however contains some interesting information.
Published: 2015-Jan
Comparison of Cloud Provider’s Instances performance
From my CMIPS (Cloud Million Instructions per second) a performance comparison of different Instances, from different Cloud Providers, compared to bare metal as well.
Is old, from 2015, however brings very valuable information.
Published: 2015-Jan

The Cloud is for Scaling
The Cloud is for Startups, and for Scaling and for Enterprises. Nothing more. Published: 2013-Sept Views: 12,316 views
Creating a RabbitMQ Docker Container accessed with Python and pika
Published: 2022-July Views: 1,626 views
How to deploy a DigitalOcean droplet (instance) and use userdata
Published: 2022-June Views: 956 views
Renewing a SSL Certificate for Apache2 in Ubuntu 20.04
Published: 2022-Mar Views: 1,894 views
Linux Command Line tools I usually install (if they are not on the system)
Published: 2016-March Views: 13,743 views

Troubleshooting upgrading and loading a ZFS module in RHEL7.4
Published: 2018-July Views: 12,854 views
A sample forensic post mortem for a iSCSI Initiator (client) that had connectivity problems to the Server (Troubleshooting)
Published: 2019-August Views: 6,917 views
Creating a content filter for Postfix in PHP
Published: 2016-June Views: 26,216 views
Stopping definitively the massive Distributed DoS attack
Published: 2015-Feb Views: 28,672 views
Stopping and investigating a DoS XMLRPC attack
Published: 2014-August Views: 149,523 views
Stopping a BitTorrent DDoS attack
Published: 2015-January Views: 69,317 views
Dropping caches in Linux, to check if memory is actually being used
Published: 2019-April Views: 3,090 views
Troubleshooting a shell prompt irresponsible/that locks intermittently
Published: 2020-April Views: 5,343 views
Post-Mortem: The mystery of the duplicated Transactions into an e-Commerce
Published: 2020-Nov Views: 5,579 views
Adding a swapfile on the fly as a temporary solution for a Server with few memory
Published: 2020-Nov Views: 2,207 views
Swap, swappiness, Servers not responding
Published: 2021-May Views: 2,995 views
Erasure Code
My project for infinite Storage scaling with no single point of failure, based on Erasure Codes.

Published: 2022-May Views: 2,090 views
Troubleshooting apps in Linux
Published: 2013-November Views: 4,207 views
Performance of Several Languages
Published: 2014-Oct Views: 184,316 views
CSort Multithread versus Quicksort (Java)
Published: 2017-March Views: 23,395 views
CSort my algorithm that heavily beats Quicksort (Java)
Published: 2015-May Views: 15,768 views
Buy my books:
Python 3 Combat Guide
Pages: 403 DIN-A4 PDF DRM-free
Accompanying Source Code: https://gitlab.com/carles.mateo/python_combat_guide
Last Update: v.1.08 2022-05-11

Automating and Provisioning to Amazon Web Services (AWS) with boto3 SDK for Python (plus some Ansible)
Pages: 128 Full Size DIN-A4 PDF DRM-free
Last Update: v.16 2022-01-16

Docker Combat Guide
Learn Docker, focused on Developers, and Docker’s Python 3 SDK
Pages: 178 DIN-A4 PDF DRM-free
Last Update: v.25 2022-07-03

Assemble and upgrade your PC and laptops
Pages: 107 DIN-A4 PDF DRM-free
Last Update: v.0.17 2021-01-11

ZFS on Ubuntu 20.04 LTS
Pages: 159 DIN-A4 PDF DRM-free
Covers ZFS 0.8.3 version. Shows tricks, fix errors, secrets and commands against real systems with LSI Controllers, SAS SLOG ZIL devices, SATA, SSD…
Last Update: v.0.25 2022-02-07

Python 3 Exercises for Beginners
Pages: 200 DIN-A4 PDF DRM-free
Exercises for people starting coding in Python, explaining the solution, tricks, etc…
Last Update: v.48 2022-03-15
Python Open Source Utilities Python PHP Java
CTOP.py SysAdmin tool to get all the System Information at a glance
Published: 2020-Jan Views: 10,743 views
Current Version: 0.8.8 Last Update: 2022-02-13

Simple sample to print colors in Terminal
Published: 2018-May Views: 10,372 views

LDAPGUI.py a simple Python GUI application that queries LDAP
Published: 2020-Jun Views: 6,060 views

cmemgzip.py compress logs (and any file) in memory and replace uncompressed files by .gz when drive has no space left. Supports compressing by blogs to use less memory
Published: 2021-Feb Views: 3,394 views

checkswap.py Monitor the impact of swap memory pages on a live system. Compatible with Python 2.x and 3.x
Published: 2021-May Views: 2,995 views

Carleslibs v. 1.0.8 (2022-06-05) Python Open Source package.
Published: 2021-July (Updated 2022-February)Views: 3,008 views

Cliptype is a utility to paste the Clipboard into the focussed Windows. Ideal for working with Web SSH Terminal clients/QEMU/KVM that don’t support paste
Published: 2021-NovemberViews: 10,275 views
Video: Object Oriented Programming in Python 3 for beginners
Published: 2022-July Views: 784 views
For beginners: How to start coding Python with PyCharm and Git
Published: 2022-March Views: 1,650 views
Lesson 0, learning to code in Python for non programmers
Published: 2020-March Views: 6,115 views
Video for beginners: Python for, range, lists, dicts
Published: 2021 July Views: 2,296 views
Programming class for beginners on 2021-11-11.
Published: 2021-November Views: 2,156 views

Sorting an Array of Tuples with Lambda in Python (videos)
Published: 2022-May Views: 1,141 views
Learn to do Unit Testing with pytest in Python 3.
Published: 2021-October Views: 1,870 views

Video: Parse the Tables from a Website with Python pandas
Published: 2022-July Views: 793 views
A handy trick command line to get the usages of our Python Methods in the code
Published: 2019-July Views: 5,491 views
A small Python + MySql + Docker program as a sample (plus LAMP PHP sample).
Published: 2021-July Views: 8,413 views

A simple Flask Application, a Star Wars game in Python and Docker.
Published: 2021-July Views: 2,340 views

A simple Python Tic Tac Toe game.
Published: 2021-September Views: 2,018 views

Some weird things from Python 3 that you may not know.
Published: 2021-September Views: 2,306 views

Generating a Word Cloud of Tags in Python.
Published: 2021-September Views: 1,903 views

Some graphics with matplotlib.
Published: 2021-October Views: 1,933 views

Web Top – Displaying top with Python 3 Web Server and carleslibs.
Published: 2021-October Views: 1,971 views

Why I think in Python is not a good idea to raise exceptions inside your methods
Published: 2022-May Views: 1,247 views
A Sudoku Solver in Python, an engineering approach solution (with Source Code)
Published: 2022-April Views: 1,419 views
MT Notation prefix variables system for Python
Last Update: 2021-07-15 Views: 5,979 views
My PHP Script to see WordPress Posts and Views ordered by Views
Published: 2021-August Views: 2,481 views
Improving performance in PHP
Published: 2014-August Views: 30,377 views
Catalonia Framework PHP Open Source

MT Notation prefix variables system for PHP
From: 2014-July Last Update: 2021-07-15 Views: 6,325 views
Java validation Classes for Keyboard
Published: 2020-Dec Views: 29,313 views
MT Notation prefix variables system for Java
From: 2017-March Views: 5,263 views
Docker Commodity Hardware ZFS Architecture
Communicating with Docker Containers via Linux Signals and Python
Published: 2021-Nov Views: 2,359 views
Refreshing settings in a Docker immutable image with Python and Flask
Published: 2020-May Views: 5,534 views
In March 2021, Why I propose you to use Python 3.8, at least, for your Internal Automation Tools in Docker Containers and Ubuntu 20.04 LTS Published: 2021-March Views: 3,451 views
Solving the problem when running a Docker Container: standard_init_linux.go:190: exec user process caused “no such file or directory” Published: 2021-March Views: 6,207 views
Adding my Server as Docker, with PHP Catalonia Framework, explained
Published: 2019-July Views: 7,428 views
A base Dockerfile for my Jenkins (home) deployments
Published: 2021-March Views: 3,993 views
Install jenkins on Docker Ubuntu 20.04 LTS with Blue Ocean pipeline plugin and persistent Volumes in 4 minutes
Published: 2022-June Views: 1,477 views
Migrating some Services from Amazon AWS EC2 to Digital Ocean, using Docker
Published: 2021-Aug Views: 2,821 views
Have a cheap Ubuntu in your Windows or Mac with Docker
Published: 2021-September Views: 2,415 views
Video: How to create a Docker Container for Linux Apache MySQL PHP Python (LAMPP) step by step
Published: 2022-July Views: 752 views
Dealing with Performance degradation on ZFS (DRAID) Rebuilds when migrating from a single processor to a multiprocessor platform (Troubleshooting explained)
Published: 2019-June Views: 6,446 views
Solving a persistent MDRAID and ZFS problem in RHEL7.4 (Dual Port SAS drives)
Published: 2018-Oct Views: 6,014 views
Simulating a SAS physical pull out of a drive
Published: 2019-March Views: 5,848 views
Create a small partition on the drives for tests
Published: 2019-April Views: 5,946 views
zpool_watch is an Open Source Python 3 utility that watches your ZFS Pools and open a window in your Linux if there is a problem
Published: 2022-February Views: 1,229 views
Adding a RAMDISK as SLOG ZIL to ZFS
Published: 2020-August Views: 9,467 views
Some handy tricks for working with ZFS
Published: 2019-June Views: 6,451 views
ZFS Improving iSCSI for Block Devices (trick for Volumes)
Published: 2018-Oct Views: 10,802 views
Creating a compressed filesystem with Linux and ZFS
Published: 2018-Sept Views: 8,131 views
Compiling ZFS with RHEL6.10
Published: 2019-August Views: 5,551 views
My talk at OpenZFS 2018 about DRAID (San Francisco, US) Published: 2018-Sept Views: 7,323 views
Extend existing Single ZFS disk with a mirror without losing the Data on the existing drive
Published: 2021-Jan Views: 5,143 views
Resources for Microservices and Business Domain Solutions for the Cloud Architect / Microservices Architect
Published: 2019-Oct Views: 6,010 views
Scaling PhantomJS with PHP
Published: 2015-June Views: 23,098 views
Improving Performance in PHP (Stack and tricks)
Published: 2014-August Views: 30,377 views
Begin developing in Cassandra in Java, PHP or Python
Published: 2014-July Views: 12,965 views
Windows Raspberry Pi Cassandra Relational Databases
Using Docker in Windows 10 without Windows Desktop with Docker Engine and without WSL
Published: 2021-Feb Views: 3,892 views
Solving Windows 10 PRO running Active Directory as Domain Admin
Published: 2021-Jan Views: 3,034 views
Install Windows Subsystem for Linux, WSL 2 on Windows 10 64 bit, with Ubuntu, solution to error WslRegisterDistribution failed with error: 0x80070057
Published: 2021-Jan Views: 19,152 views
Programs I use for Windows in my Workstations
Published: 2019-Sept Views: 4,122 views
Using Windows 10 Appliance in Ubuntu Virtual Box 4.3.10 and later versions
Published: 2015-August Views: 34,768 views
Reinstall PIP only in Windows 10 after it got removed
Published: 2021-March Views: 3,342 views
Install a Media Player on the Raspberry Pi 4
Published: 2020-March Views: 3,849 views
Raspberry Pi 3 and OMSC Media Player
Published: 2015-April Views: 14,339 views
Solving the problem GPIO.setup(self.number, GPIO.IN, self.GPIO_PULL_UPS[self._pull]) RuntimeError: Not running on a RPi! in Ubuntu 20.04LTS
Published: 2021-Feb Views: 5,970 views
CQLSÍ a wrapper to use Cassandra from PHP
Written in 2014, a time when there were no drivers for PHP.
Published: 2014 Views: 1,524 views
Cassandra Universal Driver
A HTTP gateway for all the languages supporting curl/sockets. Written in 2014, a time when there were no drivers for many languages.
Published: 2014 Views: 1,518 views
Solving Oracle error ORA 600 [KGL-heap-size-exceeded]
Published: 2021-Febreruary Views: 12,405 views
Bash Open Source Utilities Bash My Tech Talks Miscellaneous
count_repeated_pattern_in_logs.sh
A easy way to see errors that are repeating, e.g.: NFS/iSCSI timeouts.
Published: 2020-May Views: 5,686 views
backup_partition_in_files.sh
Compressing an unmounted partition to a image file while compressing on the fly, and breaking into 1GB gz files.
Also explains in a funny way about STDIN, STDOUT, STDERR and methodology investigating in deep.
Published: 2020-May Views: 6,026 views
iostat_bandwidth.sh
See the aggregated bandwidth used by all the drives, and the maximum speed achieved.
Published: 2020-Aug Views: 5,036 views
count_lines_of_code.sh
Count the lines in .py Python source files recursively and displays individual and total results.
Published: 2021-Jan Views: 4,024 views
One line script to log the temperature of HDDs and CPUs in Ubuntu
Published: 2021-Jan Views: 3,185 views
compress_old.sh A simple Bash script to compress files in a directory, older than n days
You can use it to delete older files, or perform other commands.
Published: 2021-March Views: 3,892 views
A simple script to upload a pypi/pip package
Is what I use to maintain packages like cmemgzip, carleslibs, etc…
Published: 2021-March Views: 3,087 views
Backup and Restore your Ubuntu Linux Workstations – with support for Wine and Docker
Published: 2022-October Views: 339 views
My talk at OpenZFS 2018 about DRAID (San Francisco, US)

Published: 2018-Sept Views: 7,323 views
Google Compute Engine Talk for Group Google Developers Cork, Ireland

How to do autoscaling from 0 using Google Cloud.
Published: 2019-Feb Views: 5,588 views
How is: Working in Cork for IT Engineers
Published: 2020-Feb Views: 6,100 views

A mistake that all the universities are doing
Published: 2018-Jun Views: 8,021 views

Some advice for WFH (Working from Home/Remotely)
Published: 2020-May Views: 8,505 views

My radio program at RAB 2022-06-27 [Catalan and English]
Published: 2022-June Views: 767 views

News from the Blog 2022-06-22
Published: 2022-June Views: 797 views

News from the Blog 2022-05-22
Published: 2022-May Views: 1,032 views

News from the Blog 2022-04-22
Published: 2022-April Views: 1,211 views

News from the Blog 2022-03-22
Published: 2022-March Views: 1,638 views

News from the Blog 2022-02-22
Published: 2022-February Views: 1,629 views

Old News:

Installing PHP environment for development in Windows

This article is for my students learning PHP, or for any student that wants to learn PHP and uses a Windows computer for that.

For this we will install:

XAMPP, which is available for Windows, Mac OS and Linux.

You can download it from: https://www.apachefriends.org/

XAMPP installs together:

  • Apache
  • MariaDB
  • PHP
  • Perl

Install WAMPP instead of XAMP (if you prefer WAMPP)

Alternatively you can install WAMPP, which installs:

  • Apache
  • MySQL
  • PHP
  • PHPMyAdmin

https://www.wampserver.com/en/

Development IDE

As Development Environment we will use PHPStorm, from Jetbrains.

https://www.jetbrains.com/phpstorm/

Testing the installation of XAMPP

The default directory for the PHP files is C:\xampp\htdocs

Create a file in c:\xampp\htdocs named hello.php

<?php
$s_today = date("Y-m-d");
echo "Hello! Today is ".$s_today;
?>

Now start Apache:

  1. Open the XAMPP Control Panel
  2. Start the Apache Server
You should see at least port 80 for Apache

And test the new page, with the browser, opening:

http://localhost/hello.php

Backup and Restore your Ubuntu Linux Workstations

This is a mechanism I invented and I’ve been using for decades, to migrate or clone my Linux Desktops to other physical servers.

This script is focused on doing the job for Ubuntu but I was doing this already 30 years ago, for X Window as I was responsible of the Linux platform of a ISP (Internet Service Provider). So, it is compatible with any Linux Desktop or Server.

It has the advantage that is a very lightweight backup. You don’t need to backup /etc or /var as long as you install a new OS and restore the folders that you did backup. You can backup and restore Wine (Windows Emulator) programs completely and to/from VMs and Instances as well.

It’s based on user/s rather than machine.

And it does backup using the Timestamp, so you keep all the different version, modified over time. You can fusion the backups in the same folder if you prefer avoiding time versions and keep only the latest backup. If that’s your case, then replace s_PATH_BACKUP_NOW=”${s_PATH_BACKUP}${s_DATETIME}/” by s_PATH_BACKUP_NOW=”${s_PATH_BACKUP}” for instance. You can also add a folder for machine if you prefer it, for example if you use the same userid across several Desktops/Servers.

I offer you a much simplified version of my scripts, but they can highly serve your needs.

#!/usr/bin/env bash

# Author: Carles Mateo
# Last Update: 2022-10-23 10:48 Irish Time

# User we want to backup data for
s_USER="carles"
# Target PATH for the Backups
s_PATH_BACKUP="/home/${s_USER}/Desktop/Bck/"

s_DATE=$(date +"%Y-%m-%d")
s_DATETIME=$(date +"%Y-%m-%d-%H-%M-%S")

s_PATH_BACKUP_NOW="${s_PATH_BACKUP}${s_DATETIME}/"

echo "Creating path $s_PATH_BACKUP and $s_PATH_BACKUP_NOW"
mkdir $s_PATH_BACKUP
mkdir $s_PATH_BACKUP_NOW

s_PATH_KEY="/home/${s_USER}/Desktop/keys/2007-01-07-cloud23.pem"
s_DOCKER_IMG_JENKINS_EXPORT=${s_DATE}-jenkins-base.tar
s_DOCKER_IMG_JENKINS_BLUEOCEAN2_EXPORT=${s_DATE}-jenkins-blueocean2.tar
s_PGP_FILE=${s_DATETIME}-pgp.zip

# Version the PGP files
echo "Compressing the PGP files as ${s_PGP_FILE}"
zip -r ${s_PATH_BACKUP_NOW}${s_PGP_FILE} /home/${s_USER}/Desktop/PGP/*

# Copy to BCK folder, or ZFS or to an external drive Locally as defined in: s_PATH_BACKUP_NOW
echo "Copying Data to ${s_PATH_BACKUP_NOW}/Data"
rsync -a --exclude={} --acls --xattrs --owner --group --times --stats --human-readable --progress -z "/home/${s_USER}/Desktop/data/" "${s_PATH_BACKUP_NOW}data/"
rsync -a --exclude={'Desktop','Downloads','.local/share/Trash/','.local/lib/python2.7/','.local/lib/python3.6/','.local/lib/python3.8/','.local/lib/python3.10/','.cache/JetBrains/'} --acls --xattrs --owner --group --times --stats --human-readable --progress -z "/home/${s_USER}/" "${s_PATH_BACKUP_NOW}home/${s_USER}/"
rsync -a --exclude={} --acls --xattrs --owner --group --times --stats --human-readable --progress -z "/home/${s_USER}/Desktop/code/" "${s_PATH_BACKUP_NOW}code/"


echo "Showing backup dir ${s_PATH_BACKUP_NOW}"
ls -hal ${s_PATH_BACKUP_NOW}

df -h /

See how I exclude certain folders like the Desktop or Downloads with –exclude.

It relies on the very useful rsync program. It also relies on zip to compress entire folders (PGP Keys on the example).

If you use the second part, to compress Docker Images (Jenkins in this example), you will run it as sudo and you will need also gzip.

# continuation... sudo running required.

# Save Docker Images
echo "Saving Docker Jenkins /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_EXPORT}"
sudo docker save jenkins:base --output /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_EXPORT}
echo "Saving Docker Jenkins /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_BLUEOCEAN2_EXPORT}"
sudo docker save jenkins:base --output /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_BLUEOCEAN2_EXPORT}
echo "Setting permissions"
sudo chown ${s_USER}.${s_USER} /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_EXPORT}
sudo chown ${s_USER}.${s_USER} /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_BLUEOCEAN2_EXPORT}
echo "Compressing /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_EXPORT}"
gzip /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_EXPORT}
gzip /home/${s_USER}/Desktop/Docker_Images/${s_DOCKER_IMG_JENKINS_BLUEOCEAN2_EXPORT}

rsync -a --exclude={} --acls --xattrs --owner --group --times --stats --human-readable --progress -z "/home/${s_USER}/Desktop/Docker_Images/" "${s_PATH_BACKUP_NOW}Docker_Images/"

There is a final part, if you want to backup to a remote Server/s using ssh:

# continuation... to copy to a remote Server.

s_PATH_REMOTE="bck7@cloubbck11.carlesmateo.com:/Bck/Desktop/${s_USER}/data/"

# Copy to the other Server
rsync -e "ssh -i $s_PATH_KEY" -a --exclude={} --acls --xattrs --owner --group --times --stats --human-readable --progress -z "/home/${s_USER}/Desktop/data/" ${s_PATH_REMOTE}

I recommend you to use the same methodology in all your Desktops, like for example, having a data/ folder in the Desktop for each user.

You can use Erasure Code to split the Backups in blocks and store a piece in different Cloud Providers.

Also you can store your Backups long-term, with services like Amazon Glacier.

Other ideas are storing certain files in git and in Hadoop HDFS.

If you want you can CRC your files before copying to another device or server.

You will use tools like: sha512sum or md5sum.

CTOP.py video on the Activision Blizzard King IT Demos 2021 February

I’ve good memories of this video.

In the middle of pandemic, with all commerce’s closed and no access to better cameras or equipment, I demonstrated the plug-in architecture that I created and I added to my CTOP.py Open Source Python Monitoring tool in a global conference for all IT in ABK (Activision Blizzard King).

I was so proud.

For that I cloned ctop into a Raspberry Pi 4 with Ubuntu LTS and had that motherboard which is a Christmas Tree LED attached to the GPIO.

As the CPU load on the Raspberry was low, the LED’s were green, and a voice (recorded and provided by an Irish friend) was played “The System is Healthy”.

Then I added load to the CPU and the LED’s changed.

And I added more load to the CPU and the LED’s turned to Red and and human voice “CPU load is too high”.

Voice is only played after a change in the state and with a cool down of a minute, to prevent flapping situations to keep the program chatting like a parrot :)

I should have shaved myself, but you know, it was a savage pandemic.

Also a manager from Blizzard DM me and told me that the touch pad being emerged was due to the battery swallowing and that it could explode, so I requested a replacement. Then I explained to other colleagues with the same symptom, and to others with no problems so they are not at risk if the same happened to them.

WFH made things that would be quickly detected in the offices by others (like the touchpad emerging) go unnoticed.

if you are looking for source code, it is in the CTOP’s gitlab repository. However it’s advanced Python plugin architecture code.

If you just look for a sample of how to power on the LED’s in different colors, and the tricks for solving any problem you may encounter, then look at it here:

https://blog.carlesmateo.com/2021/02/16/raspberry-pi-solving-the-problem-gpio-setupself-number-gpio-in-self-gpio_pull_upsself-_pull-runtimeerror-not-running-on-a-rpi-in-ubuntu-20-04lts/

Docker with Ubuntu with telnet server and Python code to access via telnet

Explanations building the Container and running the python code

Here you can see this Python code to connect via Telnet and executing a command in a Server:

File: telnet_demo.py

#!/usr/bin/env python3
import telnetlib

s_host = "localhost"
s_user = "telnet"
s_password = "telnet"

o_tn = telnetlib.Telnet(s_host)

o_tn.read_until(b"login: ")
o_tn.write(s_user.encode('ascii') + b"\n")

o_tn.read_until(b"Password: ")

o_tn.write(s_password.encode('ascii') + b"\n")

o_tn.write(b"hostname\n")
o_tn.write(b"uname -a\n")
o_tn.write(b"ls -hal /\n")
o_tn.write(b"exit\n")

print(o_tn.read_all().decode('ascii'))

File: Dockerfile

FROM ubuntu:20.04

MAINTAINER Carles Mateo

ARG DEBIAN_FRONTEND=noninteractive

# This will make sure printing in the Screen when running in detached mode
ENV PYTHONUNBUFFERED=1

RUN apt-get update -y && apt install -y sudo telnetd vim systemctl  && apt-get clean

RUN adduser -gecos --disabled-password --shell /bin/bash telnet

RUN echo "telnet:telnet" | chpasswd

EXPOSE 23

CMD systemctl start inetd; while [ true ]; do sleep 60; done

You can see that I use chpasswd command to change the password for the user telnet and set it to telnet. That deals with the complexity of setting the encrypted password.

File: build_docker.sh

#!/bin/bash

s_DOCKER_IMAGE_NAME="ubuntu_telnet"

echo "We will build the Docker Image and name it: ${s_DOCKER_IMAGE_NAME}"
echo "After, we will be able to run a Docker Container based on it."

printf "Removing old image %s\n" "${s_DOCKER_IMAGE_NAME}"
sudo docker rm "${s_DOCKER_IMAGE_NAME}"

printf "Creating Docker Image %s\n" "${s_DOCKER_IMAGE_NAME}"
sudo docker build -t ${s_DOCKER_IMAGE_NAME} .
# If you don't want to use cache this is your line
# sudo docker build -t ${s_DOCKER_IMAGE_NAME} . --no-cache

i_EXIT_CODE=$?
if [ $i_EXIT_CODE -ne 0 ]; then
    printf "Error. Exit code %s\n" ${i_EXIT_CODE}
    exit
fi

echo "Ready to run ${s_DOCKER_IMAGE_NAME} Docker Container"
echo "To run in type: sudo docker run -it -p 23:23 --name ${s_DOCKER_IMAGE_NAME} ${s_DOCKER_IMAGE_NAME}"

When you run sudo ./build_docker.sh the image will be built. Then run it with:

sudo docker run -it -p 23:23 --name ubuntu_telnet ubuntu_telnet

If you get an error indicating that the port is in use, then your computer has already a process listening on the port 23, use another.

You will be able to stop the Container by pressing CTRL + C

From another terminal run the Python program:

python3 ./telnet_demo.py

Validate IP Addresses and Networks with CIDR in Python

Python has a built-in package named ipaddress

You don’t need to install anything to use it.

This simple code shows how to use it

import ipaddress


def check_ip(s_ip_or_net):
    b_valid = True
    try:
        # The IP Addresses are expected to be passed without / even if it's /32 it would fail
        # If it uses / so, the CIDR notation, check it as a Network, even if it's /32
        if "/" in s_ip_or_net:
            o_net = ipaddress.ip_network(s_ip_or_net)
        else:
            o_ip = ipaddress.ip_address(s_ip_or_net)

    except ValueError:
        b_valid = False

    return b_valid


if __name__ == "__main__":
    a_ips = ["127.0.0.2.4",
             "127.0.0.0",
             "192.168.0.0",
             "192.168.0.1",
             "192.168.0.1 ",
             "192.168.0. 1",
             "192.168.0.1/32",
             "192.168.0.1 /32",
             "192.168.0.0/32",
             "192.0.2.0/255.255.255.0",
             "0.0.0.0/31",
             "0.0.0.0/32",
             "0.0.0.0/33",
             "1.2.3.4",
             "1.2.3.4/24",
             "1.2.3.0/24"]

    for s_ip in a_ips:
        b_success = check_ip(s_ip)
        if b_success is True:
            print(f"The IP Address or Network {s_ip} is valid")
        else:
            print(f"The IP Address or Network {s_ip} is not valid")

And the output is like this:

The IP Address or Network 127.0.0.2.4 is not valid
The IP Address or Network 127.0.0.0 is valid
The IP Address or Network 192.168.0.0 is valid
The IP Address or Network 192.168.0.1 is valid
The IP Address or Network 192.168.0.1  is not valid
The IP Address or Network 192.168.0. 1 is not valid
The IP Address or Network 192.168.0.1/32 is valid
The IP Address or Network 192.168.0.1 /32 is not valid
The IP Address or Network 192.168.0.0/32 is valid
The IP Address or Network 192.0.2.0/255.255.255.0 is valid
The IP Address or Network 0.0.0.0/31 is valid
The IP Address or Network 0.0.0.0/32 is valid
The IP Address or Network 0.0.0.0/33 is not valid
The IP Address or Network 1.2.3.4 is valid
The IP Address or Network 1.2.3.4/24 is not valid
The IP Address or Network 1.2.3.0/24 is valid

As you can read in the code comments, ipaddress.ip_address() will not validate an IP Address with the CIDR notation, even if it’s /32.

You should strip the /32 or use ipaddress.ip_network() instead.

As you can see 1.2.3.4/24 is returned as not valid.

You can pass the parameter strict=False and it will be returned as valid.

ipaddress.ip_network(s_ip_or_net, strict=False)

See where is the space used in your Android phone from Ubuntu Terminal

So, you may have your Android phone full and you don’t know where the space is.

You may have tried Apps for Android but none shows the information in the detail you would like. Linux to the rescue.

First of all you need a cable able to transfer Data. It is a cable that will be connected to your computer, normally with an USB 3.0 cable and to your smartphone, normally with USB-C.

Sometimes phone’s connectors are dirty and don’t allow a stable connection. Your connections should allow a stable connection, otherwise the connection will be interrupted in the middle.

Once you connect the Android smartphone to the computer, unlock the phone and authorize the data connection.

You’ll see that your computer recognizes the phone:

Open the terminal and enter this directory:

cd /run/user/1000/gvfs/

Here you will see your device and the name is very evident.

The usual is to have just one device listed, but if you had several Android devices attached you may want to query first, in order to identify it.

The Android devices use a protocol named Media Transfer Protocol (MTP) when connecting to the USB port, and that’s different on the typical way to access the USB port.

usb-devices  | grep "Manufacturer=" -B 3

Run this command to see all the devices connected to the USB.

You may see Manufacturer=SAMSUNG or Manufacturer=OnePlus etc…

The information returned will allow you to identify your device in /run/user/1000/gvfs/

You may get different type of outputs, but if you get:

T:  Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 13 Spd=480 MxCh= 0

your device can be accessed inside:

cd mtp\:host\=%5Busb%3A002%2C013%5D/

There you’ll see Card and Phone.

You can enter the Phone internal storage or the SD Card storage directory:

cd Phone

To see how the space is distributed nicely I recommend you to use the program ncdu if you don’t have you can install it with:

sudo apt install ncdu

Then run ncdu:

ncdu

It will calculate the space…

… and let you know, sorted from more to less, and will allow you to browse the sub-directories with the keyboard arrow keys and enter to get major clarity.

For example, in my case I saw 8.5 GB in the folder Movies on the phone, where I didn’t download any movie, so I checked.

I entered inside by pressing Enter:

So Instagram App was keeping a copy all the videos I uploaded, in total 8.5 GB of my Phone’s space and never releasing them!.

Example for the SD card, where the usage was as expected:

News from the blog 2022-07-22

Carles in the News

For all my friends and followers, I started to translate my radio space “El nou món digital” (in Catalan) to English “The New Digital World”. I cover Science, Technology, Entertainment and Video games.

You can see the first programs I translated here:

Catalan and English programs RAB

And the script and links mentioned here:

https://blog.carlesmateo.com/2022/06/20/rab-el-nou-mon-digital-2022-06-27-ca/

Social

I’ve created an Instagram fan page for me / for the blog.

It is open for everybody.

https://www.instagram.com/blog_carlesmateo/

Videos for learning how to code

Learning How to code Python Unit Tests with pytest from the scratch, for beginners:

I added it to my series of videos:

https://blog.carlesmateo.com/learn-python-3-unit-testing/

Video for learning how to use RabbitMQ with Python in a Docker Container

https://blog.carlesmateo.com/2022/07/20/creating-a-rabbitmq-docker-container-accessed-with-python-and-pika/

Site carlesmateo.com

I use mostly this site https://blog.carlesmateo.com to centralize everything, so I’ve kept http://carlesmateo.com as a simple landing page made with my old (from 2013) ultra fast PHP Framework Catalonia Framework.

I decided to create a Jenkins Pipeline to deploy any updates to this pages and I updated it a bit at least to provide the most common information searched.

Don’t expect anything fancy at Front End level. :)

Cloud

I created a video about how to provision a Ubuntu Droplet in Digital Ocean.

It’s just for beginners, or if you used other CSP’s and you wonder how Digital Ocean user interface is.

It is really easy, to be honest. Amazon AWS should learn from them.

I also created another about how to provision using User Data Cloud Init feature:

https://blog.carlesmateo.com/2022/06/25/how-to-deploy-a-digitalocean-droplet-instance-and-use-userdata/

Books

My Books

I have updated Docker Combat Guide to show how to work with different users in the Dockerfile and accessing an interactive terminal.

I have also added how to create a Jenkins containerized.

Books I bought > CI/CD

I recommend you these books:

I’ve created a video about how to deploy jenkins in Docker, following the official documentation, in 4 minutes.

Install jenkins on Docker in ubuntu in 4 minutes

And posted an article about solving the error load key invalid format when provisioning from Jenkins with your SSH .pem Key in a variable.

https://blog.carlesmateo.com/2022/07/05/solving-linux-load-key-ssh_yourserver-invalid-format-when-provisioning-from-jenkins/

Open Source from Carles

CTOP.py

I have released a new version of CTOP, ctop.py version 0.8.9.

This version fixes few bugs, and adds better Unit Testing Code Coverage, and is integrated with jenkins (provides Jenkinsfile and a Dockerfile ready to automate the testing pipeline)

Sudo ku solver, Sudoku solver in Python, and Engineering solving problem approach

I’ve created this video explaining my experience writing a program to solve two impossible, very annoying Sudokus. :)

https://blog.carlesmateo.com/2022/04/26/working-on-a-sudoku-solver-in-python-source-code/

Commander Turtle: a small program in Python so children can learn to code by drawing

Children can learn to code and share their scripts, which are comma separated, easily.

Commander Turtle

My life at Activision Blizzard

We have released World of Warcraft Dragonflight Alpha.

In the sync meetings I lead with Wow SRE and product Team I was informed that streaming would be open. Myself I was granted to stream over twitch, but so far I didn’t want to stream video games in my engineering channels. It’s different kind of audiences IMO. Let me know if you would like to get video game streams in my streaming channels.

Lich King

Humor

If you have been in a madness of Servers of a Cluster getting irresponsible and having to cold reboot them from remote hands iDracs or similar, you know why my friends sent me this image :D

Creating a RabbitMQ Docker Container accessed with Python and pika

In this video, that I streamed on Twitch, I demonstrate the code showed here.

I launch the Docker Container and operated it a bit, so you can get to learn few tricks.

I created the RabbitMQ Docker installation based on the official RabbitMQ installation instructions for Ubuntu/Debian:

https://www.rabbitmq.com/install-debian.html#apt-cloudsmith

One interesting aspect is that I cover how the messages are delivered as byte sequence. I show this by sending Unicode characters

Files in the project

Dockerfile

FROM ubuntu:20.04

MAINTAINER Carles Mateo

ARG DEBIAN_FRONTEND=noninteractive

# This will make sure printing in the Screen when running in dettached mode
ENV PYTHONUNBUFFERED=1

ARG PATH_RABBIT_INSTALL=/tmp/rabbit_install/

ARG PATH_RABBIT_APP_PYTHON=/opt/rabbit_python/

RUN mkdir $PATH_RABBIT_INSTALL

COPY cloudsmith.sh $PATH_RABBIT_INSTALL

RUN chmod +x ${PATH_RABBIT_INSTALL}cloudsmith.sh

RUN apt-get update -y && apt install -y sudo python3 python3-pip mc htop less strace zip gzip lynx && apt-get clean

RUN ${PATH_RABBIT_INSTALL}cloudsmith.sh

RUN service rabbitmq-server start

RUN mkdir $PATH_RABBIT_APP_PYTHON

COPY requirements.txt $PATH_RABBIT_APP_PYTHON

WORKDIR $PATH_RABBIT_APP_PYTHON

RUN pwd

RUN pip install -r requirements.txt

COPY *.py $PATH_RABBIT_APP_PYTHON

COPY loop_send_get_messages.sh $PATH_RABBIT_APP_PYTHON

RUN chmod +x loop_send_get_messages.sh

CMD ./loop_send_get_messages.sh

cloudsmith.sh

#!/usr/bin/sh
# From: https://www.rabbitmq.com/install-debian.html#apt-cloudsmith

sudo apt-get update -y && apt-get install curl gnupg apt-transport-https -y

## Team RabbitMQ's main signing key
curl -1sLf "https://keys.openpgp.org/vks/v1/by-fingerprint/0A9AF2115F4687BD29803A206B73A36E6026DFCA" | sudo gpg --dearmor | sudo tee /usr/share/keyrings/com.rabbitmq.team.gpg > /dev/null
## Cloudsmith: modern Erlang repository
curl -1sLf https://dl.cloudsmith.io/public/rabbitmq/rabbitmq-erlang/gpg.E495BB49CC4BBE5B.key | sudo gpg --dearmor | sudo tee /usr/share/keyrings/io.cloudsmith.rabbitmq.E495BB49CC4BBE5B.gpg > /dev/null
## Cloudsmith: RabbitMQ repository
curl -1sLf https://dl.cloudsmith.io/public/rabbitmq/rabbitmq-server/gpg.9F4587F226208342.key | sudo gpg --dearmor | sudo tee /usr/share/keyrings/io.cloudsmith.rabbitmq.9F4587F226208342.gpg > /dev/null

## Add apt repositories maintained by Team RabbitMQ
sudo tee /etc/apt/sources.list.d/rabbitmq.list <<EOF
## Provides modern Erlang/OTP releases
##
deb [signed-by=/usr/share/keyrings/io.cloudsmith.rabbitmq.E495BB49CC4BBE5B.gpg] https://dl.cloudsmith.io/public/rabbitmq/rabbitmq-erlang/deb/ubuntu bionic main
deb-src [signed-by=/usr/share/keyrings/io.cloudsmith.rabbitmq.E495BB49CC4BBE5B.gpg] https://dl.cloudsmith.io/public/rabbitmq/rabbitmq-erlang/deb/ubuntu bionic main

## Provides RabbitMQ
##
deb [signed-by=/usr/share/keyrings/io.cloudsmith.rabbitmq.9F4587F226208342.gpg] https://dl.cloudsmith.io/public/rabbitmq/rabbitmq-server/deb/ubuntu bionic main
deb-src [signed-by=/usr/share/keyrings/io.cloudsmith.rabbitmq.9F4587F226208342.gpg] https://dl.cloudsmith.io/public/rabbitmq/rabbitmq-server/deb/ubuntu bionic main
EOF

## Update package indices
sudo apt-get update -y

## Install Erlang packages
sudo apt-get install -y erlang-base \
                        erlang-asn1 erlang-crypto erlang-eldap erlang-ftp erlang-inets \
                        erlang-mnesia erlang-os-mon erlang-parsetools erlang-public-key \
                        erlang-runtime-tools erlang-snmp erlang-ssl \
                        erlang-syntax-tools erlang-tftp erlang-tools erlang-xmerl

## Install rabbitmq-server and its dependencies
sudo apt-get install rabbitmq-server -y --fix-missing

build_docker.sh

#!/bin/bash

s_DOCKER_IMAGE_NAME="rabbitmq"

echo "We will build the Docker Image and name it: ${s_DOCKER_IMAGE_NAME}"
echo "After, we will be able to run a Docker Container based on it."

printf "Removing old image %s\n" "${s_DOCKER_IMAGE_NAME}"
sudo docker rm "${s_DOCKER_IMAGE_NAME}"

printf "Creating Docker Image %s\n" "${s_DOCKER_IMAGE_NAME}"
sudo docker build -t ${s_DOCKER_IMAGE_NAME} . --no-cache

i_EXIT_CODE=$?
if [ $i_EXIT_CODE -ne 0 ]; then
    printf "Error. Exit code %s\n" ${i_EXIT_CODE}
    exit
fi

echo "Ready to run ${s_DOCKER_IMAGE_NAME} Docker Container"
echo "To run in type: sudo docker run -it --name ${s_DOCKER_IMAGE_NAME} ${s_DOCKER_IMAGE_NAME}"
echo "or just use run_in_docker.sh"

requirements.txt

pika

loop_send_get_messages.sh

#!/bin/bash

echo "Starting RabbitMQ"
service rabbitmq-server start

echo "Launching consumer in background which will be listening and executing the callback function"
python3 rabbitmq_getfrom.py &

while true; do

    i_MESSAGES=$(( RANDOM % 10 ))

    echo "Sending $i_MESSAGES messages"
    for i_MESSAGE in $(seq 1 $i_MESSAGES); do
        python3 rabbitmq_sendto.py
    done

    echo "Sleeping 5 seconds"
    sleep 5

done

echo "Exiting loop"

rabbitmq_sendto.py

#!/usr/bin/env python3
import pika
import time

connection = pika.BlockingConnection(pika.ConnectionParameters(host="localhost"))

channel = connection.channel()

channel.queue_declare(queue="hello")

s_now = str(time.time())

s_message = "Hello World! " + s_now + " Testing Unicode: çÇ àá😀"
channel.basic_publish(exchange="", routing_key="hello", body=s_message)
print(" [x] Sent '" + s_message + "'")
connection.close()

rabbitmq_getfrom.py

#!/usr/bin/env python3
import pika


def callback(ch, method, properties, body):
    # print(f" [x] Received in channel: {ch} method: {method} properties: {properties} body: {body}")
    print(f" [x] Received body: {body}")


connection = pika.BlockingConnection(pika.ConnectionParameters(host="localhost"))

channel = connection.channel()

channel.queue_declare(queue="hello")

print(" [*] Waiting for messages. To exit press Ctrl+C")

# This will loop
channel.basic_consume(queue="hello", on_message_callback=callback)
channel.start_consuming()

print("Finishing consumer")

Video: Parse the Tables from a Website with Python pandas

A quick video, of 3 minutes, that shows you how it works.

If you don’t have pandas installed you’ll have to install it and lxml, otherwise you’ll get an error:

  File "/home/carles/Desktop/code/carles/blog.carlesmateo.com-source-code/venv/lib/python3.8/site-packages/pandas/io/html.py", line 872, in _parser_dispatch
    raise ImportError("lxml not found, please install it")
ImportError: lxml not found, please install it

You can install both from PyCharm or from command line with:

pip install pandas
pip install lxml

And here the source code:

import pandas as pd


if __name__ == "__main__":

    # Do not truncate the data when printing
    pd.set_option('display.max_colwidth', None)
    # Do not truncate due to length of all the columns
    pd.set_option('display.max_columns', None)
    pd.set_option('display.max_rows', None)
    pd.set_option('display.width', 2000)
    # pd.set_option('display.float_format', '{:20,.2f}'.format)

    o_pd_my_movies = pd.read_html("https://blog.carlesmateo.com/movies-i-saw/")
    print(len(o_pd_my_movies))

    print(o_pd_my_movies[0])

Video: How to create a Docker Container for LAMPP step by step

How to create a Docker Container for Linux Apache MySQL PHP and Python for beginners.

Note: Containers are not persistent. Use this for tests only. If you want to keep persistent information use Volumes.

Sources: https://gitlab.com/carles.mateo/blog.carlesmateo.com-source-code/-/tree/master/twitch/live_20220708_dockerfile_lamp

File: Dockerfile

FROM ubuntu:20.04

MAINTAINER Carles Mateo

ARG DEBIAN_FRONTEND=noninteractive

RUN apt update && \
    apt install -y vim python3-pip &&  \
    apt install -y net-tools mc vim htop less strace zip gzip lynx && \
    apt install -y apache2 mysql-server ntpdate libapache2-mod-php7.4 mysql-server php7.4-mysql php-dev libmcrypt-dev php-pear && \
    apt install -y git && apt autoremove && apt clean && \
    pip3 install pytest

RUN a2enmod rewrite

RUN echo "Europe/Ireland" | tee /etc/timezone

ENV APACHE_RUN_USER  www-data
ENV APACHE_RUN_GROUP www-data
ENV APACHE_LOG_DIR   /var/log/apache2
ENV APACHE_PID_FILE  /var/run/apache2/apache2.pid
ENV APACHE_RUN_DIR   /var/run/apache2
ENV APACHE_LOCK_DIR  /var/lock/apache2
ENV APACHE_LOG_DIR   /var/log/apache2

COPY phpinfo.php /var/www/html/

RUN service apache2 restart

EXPOSE 80

CMD ["/usr/sbin/apache2", "-D", "FOREGROUND"]

File: phpinfo.php

<html>
<?php

// Show all information, defaults to INFO_ALL
phpinfo();

// Show just the module information.
// phpinfo(8) yields identical results.
phpinfo(INFO_MODULES);
?>
</html>

File: build_docker.sh

#!/bin/bash

s_DOCKER_IMAGE_NAME="lampp"

echo "We will build the Docker Image and name it: ${s_DOCKER_IMAGE_NAME}"
echo "After, we will be able to run a Docker Container based on it."

printf "Removing old image %s\n" "${s_DOCKER_IMAGE_NAME}"
sudo docker rm "${s_DOCKER_IMAGE_NAME}"

printf "Creating Docker Image %s\n" "${s_DOCKER_IMAGE_NAME}"
# sudo docker build -t ${s_DOCKER_IMAGE_NAME} . --no-cache
sudo docker build -t ${s_DOCKER_IMAGE_NAME} .

i_EXIT_CODE=$?
if [ $i_EXIT_CODE -ne 0 ]; then
    printf "Error. Exit code %s\n" ${i_EXIT_CODE}
    exit
fi

echo "Ready to run ${s_DOCKER_IMAGE_NAME} Docker Container"
echo "To run in type: sudo docker run -p 80:80 --name ${s_DOCKER_IMAGE_NAME} ${s_DOCKER_IMAGE_NAME}"
echo "or just use run_in_docker.sh"

echo
echo "If you want to debug do:"
echo "docker exec -i -t ${s_DOCKER_IMAGE_NAME} /bin/bash"