Jose Castrillo

DevOps Projects

Sat, 28 Feb 2026 00:00:00 +0000

Senior DevOps Engineer - Projects & Professional Journey

My Career Journey

Sat, 28 Feb 2026 00:00:00 +0000

Senior DevOps Engineer - Projects & Professional Journey

Linux on Business

Fri, 07 Nov 2025 00:00:00 +0000

Why Linux 🐧? the question isn’t why Linux ? the real question is why not ? did you try it?

Linux is widely regarded as the best option for development, DevOps, hybrid cloud solutions, and even as a desktop for home and office environments due to its open-source nature, robust ecosystem, scalability, security, and cost-effectiveness. Its flexibility allows seamless integration across diverse platforms, from small IoT devices to large-scale cloud infrastructures, making it the backbone of modern technology stacks.

Thu, 02 Oct 2025 00:00:00 +0000

Cloud Development Operations - [currently]

Jose Castrillo

Title: Cloud Development Operations
Public Cloud: AWS
Started: Nov 2024 - Currently
Company: Aubay
Client: Allianz

As part of the DevOps team, I design, maintain, and automate AWS infrastructure with Terraform and Terragrunt, following Infrastructure as Code (IaC) principles. I drive automation, CI/CD adoption, and cloud cost/security optimization across environments.

Curriculum for Allianz Technology

Fri, 30 May 2025 00:00:00 +0000

Jose Castrillo

📱 Phone: +xxxxxxxx

✉️ Email: jose@castrillo.addy.io

🌍 Location: Barcelona, Spain.

Title: Cloud Development Operations
Public Cloud: AWS
Started: Nov 2024 - Currently
Company: Aubay

As part of the DevOps team, I specialize in designing, maintaining, and automating AWS infrastructure using Terraform and Terragrunt, following Infrastructure as Code (IaC) principles. I support project teams by implementing infrastructure changes, deploying new environments, and ensuring stability, security, cost-efficiency, and compliance. Additionally, I contribute to the design and implementation of GitLab CI/CD pipelines tailored to project requirements, fostering collaboration and continuous improvement across cloud deployments.

🎨 Customize Your Terminal Shell with Oh My Bash

Tue, 14 Jan 2025 00:00:00 +0000

Learn how to dynamically switch themes in Oh My Bash based on your environment and directory.

👨‍💻 Tunning your Devbox shell

Fri, 26 Jul 2024 00:00:00 +0000

Using Oh-My-Bash with Jetify Devbox: A Step-by-Step Guide

If you’re a developer working with Jetify Devbox, you might have noticed that its shell environment doesn’t always play nicely with Oh-My-Bash. By following these steps, you can customize and personalize your themes and PS1 prompt to create a more enjoyable and productive shell experience.

Step 1: Install Oh-My-Bash

First, you need to install Oh-My-Bash. You can do this by running the following command in your terminal:

Automation a Nextcloud as a Podman Container

Sun, 30 Jun 2024 00:00:00 +0000

I’ve been thinking to upgrade my Nextcloud service also switching to another alternative rather than docker, hence I used podman and buildah in my solution.

From the rockylinux.org I found a nice post where it describes how to build and provisioning by using buildah and podman, it works pretty good and I added a tool in order to run it faster, called taskfile.

Requirements:

Podman
Buildah
Taskfile

Install taskfile
Clone my project
From the project you can see the task defined:

version: "3"

tasks:
  up-db:
    dir: "db/mariadb"
    preconditions:
      - test -f db-init.sh
    cmds:
      - bash db-init.sh

  create-app:
    dir: "app"
    preconditions:
      - test -f run.sh
    cmds:
      - mkdir nc nc/nextcloud nc/apps nc/config nc/data
      - task: up-db
      - bash run.sh

  build_base:
    dir: "db/base"
    preconditions:
      - test -f build.sh
    cmds:
      - bash build.sh

  build_tools:
    dir: "db/db-tools"
    preconditions:
      - test -f build.sh
    cmds:
      - bash build.sh

  build_maria:
    dir: "db/mariadb"
    preconditions:
      - test -f build.sh
    cmds:
      - bash build.sh

  build_db:
    cmds:
      - task: build_base
      - task: build_tools
      - task: build_maria

  up-app:
    cmds:
      - podman container start nextcloud

Main task to build and run nextcloud:

Goland CORS, logs and healtcheck

Sat, 01 Jun 2024 00:00:00 +0000

In this guide, we’ll walk through how to create CORS (Cross-Origin Resource Sharing) and a health check endpoint in a Golang application using the Chi router.

Setting Up Chi and CORS Middleware

We’ll use the go-chi/chi and go-chi/cors packages to handle routing and CORS in our application.

Step 1: Import Required Packages

First, make sure to import the necessary packages:

import (
	"fmt"
	"net/http"
	"log"

	"github.com/go-chi/chi"
	"github.com/go-chi/chi/middleware"
	"github.com/go-chi/cors"
	AdminMiddleware "github.com/project/api/middleware"
	"github.com/project/api/services"
	"gorm.io/gorm"
)

Step 2: Define the CORS AllowOriginFunc

We’ll define a function to specify the allowed origins for CORS. This function also logs disallowed origins:

Faster and simple maintenance page

Sun, 04 Feb 2024 00:00:00 +0000

Working on different platform either to update, patch, etc need to be notificate for those people that consume that services, it shouldn’t change if that service it’s internal, you must notificate your teams about it.

When you’re into your maintenance window you can use a faster way to broadcast everyone you’re working on it; I use this simple solution when I was working into a Jenkins migration, hence I stop the jenkins service and instead of 500 html error I developed a simple html text exposing it by a nginx container by the root path.

Como configurar un router neutro

Sun, 19 Nov 2023 00:00:00 +0000

📣 Actualizado 02/2024

Continuando con mi post anterior explico como realizar una conexion directa con tu propio router, en mi caso tengo un router gl.inet; puedes usar otro router que disponga la configuración de VLAN.

Dependiendo de tu proveedor de servicio, necesitamos ir a la siguiente pagina y busca tu VLAN, Leer con atencion las notas dejadas en la pagina!. En mi caso tengo Orange aunque a en mi zona llega por NEBA.

Trigger pipelines by using the API

Sat, 15 Jul 2023 00:00:00 +0000

When you join a new project, company, customer, etc. (you’re still in the onboarding phase 😅), meanwhile you may find that you need to make a few changes to get your team’s production pipelines up and running. In this case, you can call an API trigger from one project to another (this is just a example).

I’ve been in the situation described above before, and it was how I discovered this amazing feature in GitLab.

Mastering GitLab CI/CD, Unleashing the Power of Pipelines

Fri, 16 Jun 2023 00:00:00 +0000

Hey everyone! 👋 I hope you’re all having a fantastic summer time! 🌞

I wanted to drop a quick note to let you know that I’m currently working on something special for all my fellow developers/operations and GitLab enthusiasts out there. 🤓✨

In the upcoming posts, I’ll be sharing a treasure trove of valuable tips and tricks related to GitLab pipelines! based in my experiences 🏗️ Whether you’re a seasoned pro or just getting started with GitLab CI/CD, there’s bound to be something for everyone.

Upgrading major version Nextcloud

Sat, 20 May 2023 00:00:00 +0000

For those who have been facing the “Maintenance mode active” after applied a nextcloud upgrade by switching container image version, due a major versioning issue.

Even when you issue the occ upgrade into continer you gets hit by something like below:


www-data@87401bdd2fa8:~/html$ php /var/www/html/occ upgrade
Nextcloud or one of the apps require upgrade - only a limited number of commands are available
You may use your browser or the occ upgrade command to do the upgrade
Setting log level to debug
Exception: Updates between multiple major versions and downgrades are unsupported.
Update failed
Maintenance mode is kept active
Resetting log level

Keep a eye on this part: Updates between multiple major versions and downgrades are unsupported. as I was running 25 version I can no jump for above 27, if that’s our case, we can edit the file app/config/config.php edit the version of your nextcloud like below:

Python & Virtual Environments

Wed, 15 Mar 2023 00:00:00 +0000

When starting a Python 3 project in Linux, it’s essential to follow best practices to ensure a clean and isolated development environment. One of the recommended approaches is to utilize virtual environments. Virtual environments allow you to create an isolated environment for each project, preventing conflicts between different packages and dependencies. In this guide, we’ll walk you through the steps to set up and activate a virtual environment for your Python 3 project.

Fixing tags on Azure invoices

Tue, 21 Feb 2023 00:00:00 +0000

Merging two CSV files using Pandas in Python 3 on Linux is a quick and easy process that can save you a lot of time and effort, however in my case I used other script to extract specific tag values from a CSV file, converts them into a JSON object, and writes them to a new CSV file, in that way I provided a workaround for those tags wanted.

Java Native Memory Tracking in GNU/linux

Tue, 10 Jan 2023 00:00:00 +0000

Java provides a Native Memory Tracking feature that enables you to monitor the memory usage of your Java application. This feature is particularly useful for identifying memory leaks and optimizing the memory usage of your application. In this post, we will discuss how to activate Native Memory Tracking for a Java jar application in Linux.

Step 1: Check Java Version

First, you need to check the version of Java installed on your system using the following command:

Cloining a repo and setting up as artifact

Tue, 20 Dec 2022 00:00:00 +0000

On this post I will give you an example of how to clone a repo into your pipeline and use it for other jobs.

As you can read from Gitlab official documentation artifact can output an archive of files/directories. I set the following example:


  artifacts:
    paths:
      - <project_name>
    exclude:
      - <project_name>/.git/**/*
    expire_in: 60 seconds

We need to call the artifacts by using “artifacts” keyboard in the pipeline, in this example paths keyboard which files/directories add into artifacts.

Trigger pipelines in Gitlab

Thu, 10 Nov 2022 00:00:00 +0000

The following post is example of how to activate and use Trigger pipeline by API the official documentation over here as it mentioned is can be use “to trigger a pipeline for a specific branch or tag”; for our example I use it to activate a pipeline into specific branch.

Steps:

repoA will be the main one where the pipeline trigger it will be activate

From repoA go to Settings-CI/CD-Pipeline triggers
Click on “add trigger” copy your token
From repoB that will be our caller of the repoA pipeline create a variable where you can paste the token.
Finally into your pipeline on repoB you can add something like below:

The best part is that you can reference to specific branch ref="<branch_name>".

Creating snapshot image in Hetzner with packer

Tue, 20 Sep 2022 00:00:00 +0000

On this entry we will cover how to create an new image in Hetzner Public Cloud by using Packer, as result we willl get a snapshot and then we can generate this new instance by using the snapshot created.

Tools used so far:

Ansible
Packer
hcl2_upgrade

I did not create a repo yet because it will be the first part of a personal project I’m working on, hence I will provide a couple of templates below.

S3 by using random provider on Terraform

Sun, 24 Jul 2022 00:00:00 +0000

This is a piece of cake for most of you that are working on tf, I will drop this snippet code where you can create a S3 bucket with an unique name; as you know those requirements should fit in order to create the S3, hence we can use random_string, also we can use random_id, on this case I used random_string.

main.tf

resource "random_string" "randomz" {
  length = 8
  lower  = true
  special = false
  upper = false
}

Above is a resource block where its block label is random_string I defined the block body in that way in order to fit the S3’s requirements.

How to switch 3053 to 53 on Gl.inet

Mon, 06 Jun 2022 00:00:00 +0000

For those who has a Gl.inet router featured with Adguard on it, you should being facing a issue at Adguard when it activated at first time, from clients list the only client listed is “localhost”, the reason it’s due dnsmasq is runing on port 53 in the other hand adguard by default on port 3053, in order to solve it you have to switch them. This entry is a forward post by the workaround explained by chao-chao from gl-inet-forum I did it and it’s working from my side, below is a little summary of the steps I did:

setup auto mount smb v1.0

Fri, 27 May 2022 00:00:00 +0000

In any case you still having a device that works with smb v1.0 you can use the following way in order to mount it on your Fedora host:

Path: /etc/NetworkManager/dispatcher.d/smb-setup.sh

#!/bin/sh -e
# Script to dispatch NetworkManager events
# more over: https://stackoverflow.com/questions/16848021/linux-networkmanagers-etc-networkmanager-dispatcher-d-test-script-does-not
# Runs ifupdown scripts when NetworkManager fiddles with interfaces.
# See NetworkManager(8) for further documentation of the dispatcher events.

INF="$1" # your current interface name such as eth0, wlp4s0 and so on
STA="$2" # status such as UP or DOWN

# Send message to /var/log/messages
logger -s "$0 called for interface named $INF with $STA ..."

if [ "$INF" == "eno1" ]
then
mount -t cifs -o vers=1.0,username=admin,password=Tr3x_1986,uid=1000,gid=1000,forceuid,forcegid //10.34.1.1/1fea-6abb /home/jose/homedisk
fi

more info:

csi interface for eks by terraform

Tue, 10 May 2022 00:00:00 +0000

It has been a while since my last post, I was busy these last couples of weeks; meanwhile I’ve learned how to implement a csi interface on eks (aws k8s) and it’s pretty interesting on AWS by EKS service, thus I though it can be useful this content into a post.

Requirements:

You will need your eks already running.

I’ll point each tools, techs, etc I used on this procedure:

Ansible missing sudo

Sun, 03 Apr 2022 00:00:00 +0000

Ansible FAILED! => {"msg": "Missing sudo password"}

I have a couple of ansible-playbook, from one of my endpoint device started to prompt missing sudo password due there is needed a sudoers access, thus this is one of the solutions.

login by ssh to the device, where ansible can’t login.
go to /etc/sudoers.d/
create a new entry eg: “023_user-nopass”
add the following line “user ALL=(ALL) NOPASSWD: ALL” into the file “023_user-nopass”
change the permission by using:

sudo chmod 440 023_user-nopass

NOTE: please change value for your normal user access -not the root one-

HelloWorld Solidity

Fri, 14 Jan 2022 00:00:00 +0000

This’s my Hello World on Solidity:


// SPDX-License-Identifier: GPL-3.0

pragma solidity ^0.8.6 < 0.9.0;

contract TaskContract {
    uint nextId;

    struct Task {
        uint id;
        string name;
        string description;
    }
    Task[] tasks;

    function createTask (string memory _name, string memory _description) public {
        tasks.push(Task(nextId, _name, _description));
        nextId++;
    }
    function findIndex(uint _id) internal view returns (uint) {
            for (uint i=0;i < tasks.length; i++){
        if (tasks[i].id == _id){
            return i;
            }
        }
        revert('Task not found');
    }
    function readTask(uint _id) public view returns (uint, string memory, string memory) {
// _id ---> variable local
        uint index = findIndex(_id);
        return (tasks[index].id, tasks[index].name, tasks[index].description);
    }

    function updateTask(uint _id, string memory _name, string memory _description) public {
        uint index = findIndex(_id);
        tasks[index].name = _name;
        tasks[index].description = _description;
    }

    function deleteTask(uint _id) public{
        uint index =findIndex(_id);
        delete tasks[index];
    }

}

Tutorial followed: Solidity SCRUD

How setup a Gitlab Runner (CI)

Wed, 08 Dec 2021 00:00:00 +0000

Part I -

I’m learning Gitlab Runner and how them works on CI implementation.

GitLab Runner is an application that works with GitLab CI to run jobs in a pipeline, they are written in GO

Summary the task I will do:

Install Gitlab-runner as container(podman).
Runner registration.
- Enter the GitLab instance URL
- registration token.
- runner description.
- tags.
- Select an executor.
Create a gitlab-ci.yml

Install runner:

Create the Volume:

podman volume create gitlab-runner-config

Pull and start the container by register command, then we will prompt the data need for register the runner into the project.

Install Hetzner-CLi on Fedora by Toolbox

Sun, 04 Jul 2021 00:00:00 +0000

On this new entry I will share a briefly installation step by step by using Toolbox at Fedora 34 to use the hcloud-cli. Due we do not have an official package on fedora git-repo yet, hence we can create this container.

Pre-requirement:

Visit Hetzner Cloud Console at https://console.hetzner.cloud, select your project, and create a new API Token.

Let’s start:

1- Create a file named Dockerfile.debian with the following contents(the following image is made to use a script to named and set a token_key):

Redundant Array of Inexpensive Disks

Sun, 06 Jun 2021 00:00:00 +0000

RAID

RAID is a technology that is used to increase the performance and/or reliability of data storage. The abbreviation stands for Redundant Array of Inexpensive Disks. A RAID system consists of two or more drives working in parallel. These disks can be hard discs, but there is a trend to also use the technology for SSD (solid state drives). There are different RAID levels, each optimized for a specific situation. These are not standardized by an industry group or standardization committee.

How to install /e/OS in Gigaset GS290 from GNU/Linux

Sun, 21 Mar 2021 00:00:00 +0000

I created this post as aim to collaborate with the project and help those how are bought a Gigaset GS290 to test this great /e/ OS degoogle fork, and have been failed by using easy installer, but first I will let clearly that these steps are the steps I followed in order to set up the /e/ OS in my Gigaset.

Requirement-system:

GNU/Linux OS (in my case Fedora).**
ADB & Fastboot library latest.**
/e/OS build**
boot.img**
recovery.img**
Basic knowledge in terminal & command line.
Sudo

Requirement-smartphone:

/prometheus/data/chunks_head/ troubleshoot

Mon, 22 Feb 2021 00:00:00 +0000

I will share a little workaround in order to re-establish Prometheus service back in the game.

Origin of issue:

I’ve had an issue with my local network at home by the ISP provider, I had have shut down my RaspberryPi and other devices.

Then when I could solved the issue and all my devices were up and running I checked up my services and I found that Prometheus got stuck by a “mmap: invalid argument” message.

Setup monitoring system [Grafana+Prometheus] in RaspberryPi (Part1)

Wed, 03 Feb 2021 00:00:00 +0000

On this post I will explain how I set up a Grafana + Prometheus into a RaspberryPi with Raspbian.

Here it’s a little design where explains how it is the implementation I did:

🔵 Server: RaspberryPi 3B+

Services to install(server side):
1. Grafana
2. Prometheus (Metric collector and database)
3. Node Exporter (collector worker)

🟢 Clients: Raspberrypi Zero Fedora Workstation Debian VPS

Services to install(client side):
1. Node Exporter (collector worker).

🔵 Lets start from the server side.

Format & Mount an usb drive in GNU/Linux [terminal]

Fri, 22 Jan 2021 00:00:00 +0000

Format and Mount usb drive in GNU/Linux

Tools/commands:

lsblk
parted
df
fdisk
mkfs
wipefs

check if which blcok devices used by usb (sd) [df -h, lsblk] eg:

$ sudo fdisk -l
Disk /dev/sda: 7.2 GiB, 7736072192 bytes, 15109516 sectors
Disk model: DataTraveler 3.0
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000

Monitoring with Cockpit

Mon, 11 Jan 2021 00:00:00 +0000

On this post we are going to talk about cockpit how to monitoring and manage your GNU/Linux infrastructure. Based on the official description, Cockpit project is pretty easy to use, install and integrate, you can manage and add servers by ssh credentials to your dashboard, showing logs, monitoring containers(podman/docker), services running, disk usage, etc.

I’ve using it around 1 year, the only thing I cannot see it’s an alert tool or event trigger, maybe for the next release; is developed by RH team and open source, it’s already integrated in some of the GNU/Linux distribution ( RH, debian, ubuntu, fedora, etc).

Display Android devices from Linux workstation

Mon, 28 Dec 2020 00:00:00 +0000

I’m sure you’ve heard about Scrcpy! it’s a pretty nice tool that allows you to display and control an Android devices from your PC either usb or TCP/IP, hence on this post I will explained how to set up Scrcpy in Fedora 33 by using copr repo. It’s really useful, and believe me if I told you that; from one of my last job, one of my colleagues got the idea to install it, and thanks to that the dev team saved a lot of time testing a app integration remotely.

Serial communication Arduino

Fri, 27 Nov 2020 00:00:00 +0000

From my last post (Arduino-oled-display) I added a new function that allows me to send notification/messages from my terminal (linux) to my Arduino and it shows it through the little Oled screen. Here I will share the commands and code lines to get done the serial communication on your project.

void loop() {
  while (Serial.available() > 0)
    {
        char recieved = Serial.read();
        inData += recieved;

        // Process message when new line character is received

        if (recieved == '\n')
        {
            Serial.print("Arduino Received: ");
            Serial.print(inData);
            //digitalWrite(ledPin, HIGH);
            //
            if(inData == "HELLO\n")

            { // DON'T forget to add "\n" at the end of the string.

              Serial.println("HELLO");
              //digitalWrite(ledPin, LOW);
              display.clearDisplay();
              display.setCursor(0,0);
              display.setTextSize(2);
              display.print("Hi jose!");
              display.display();
              delay(3000);
            }
            inData = ""; // Clear received buffer
        }
    }
}

Open a Nextcloud's DB through a ssh connection

Mon, 23 Nov 2020 00:00:00 +0000

The following post explains how to open and connect your Nextcloud’s DB (MariaDB) by a ssh tunnel.

Field description:

Server side(GNULinux):
- Nextcloud: running on Docker-compose engine.
- OS: Debian with Docker compose installed.
- Database: MariaDB.
Localhost side(GNULinux):
- OS: Fedora.
- CLient: Dbeader 7.2.5

Further information you can go to my docker compose Statement here.

Edit your docker-compose.yml and add the “ports” key into the statement.

$ nano docker-compose.yml
  ports:
    - 5555:3306

port: 5555 –> Host.
port: 3306 –> Container.

From the above the port “5555” it was used as example.

Nextcloud bot as Notification System

Fri, 09 Oct 2020 00:00:00 +0000

Following the last post, where I shared how to use Telegram’s bot; on this post I’m going to explain how implement it by Chat Nextcloud API. This post is useful for those have a Nexctcloud deployment running at home/cloud.

Assuming you have already Nextcloud up and running, we can create the new user, that we are gonna use it as “BOT” we will need the chat room token and the “BOT” credentials.

Telegram Bot as Notification System

Thu, 24 Sep 2020 00:00:00 +0000

From one older post “Create a job using crontab” I used into my script the service exim4/ssmtp as mail server using gmail, but as we’re trying to walk away of Google’s jaw, I switched my notification engine to Telegram by an API service(bot)… almost it’s a step forward ! :)

Requirement:

Bot (Telegram)
Web Browser
Terminal(script)

I will assume you have already set up your Bot on Telegram with BotFather

When you have already created your Bot you can check by the API through a web browser

How to deploy Wordpress + Mariadb using Docker

Sat, 08 Aug 2020 00:00:00 +0000

Below you will see the statement I used to deploy a Wordpress as db mariadb (mysql); I shared it to you, cos I’ve been looking out for a good .yml statement piece, but some of them are older or put other set frontend as nginx, etc. I did a simple and easier deployment statement, so here we have:


version: '3.3'

services:
   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     volumes:
       - ./html:/var/www/html
     ports:
       - "8080:80"
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: password
     links:
       - db
     depends_on:
       - db

   db:
     image: mariadb:10.5.4-focal
     volumes:
       - ./db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: SECRET
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: password
     ports:
       - "3306:3306"

You can switch the local mount to volume mount it will depend of you design.

OpenVPN usando Raspberry Pi3 + Noip

Wed, 15 Jul 2020 00:00:00 +0000

Requisitos:

RaspberryPi –> https://www.raspberrypi.org/downloads/raspberry-pi-os/
OpenVPN –> https://pivpn.io/
Cuenta abierta –> https://www.noip.com/
Una IP Estatica en tu Raspberry –> Router manual
Router con capacidad de tunel VPN —> IPsec, PPTP, L2TP.
Public IP —> https://www.whatismyip.net/

Pasos:

1. Crear DNS Record A en Noip

Apunta tu IP publica
Abre tu sesion con tus credenciales en Noip
Dentro del Dashboard ve al apartado “Dynamic DNS > Create Hostname” rellena:
- hostname, ejemplo: test
- Domain, ejemplo: ddns.net
- IPv4 address: Tu IP publica
- Click en Crear

Setup Podman service in Silverblue by Systemd

Tue, 07 Jul 2020 00:00:00 +0000

Into my Devops learning path 👨‍💻 I decided to deploy a monitoring centre into my workstation where I could be able to watch my containers, resources, logs, etc and continue improving my knowledge, in my case I’m using Silverblue developed by Fedora so in here it’s a little bit different the setup; as monitoring tool I choose Cockpit for its great integration and support.

Workstation: Silverblue 🖥️
Container engine: Podman ⚙️
Monitoring tool(app/service):Cockpit 📦

I splinted out the instructions in 4 simple parts:

How to set your Domain name in Linux

Sun, 31 May 2020 00:00:00 +0000

Resume to set a domain name in Linux

concepts:

FQDN (Fully Qualified Domain Name)

eg:

hostname = server1 // FQDN = server1.example.com

1. First add FQDN to your hostname in /etc/hosts file.

# cat /etc/hosts
10.120.68.23 server1.example.com server1

confirm the FQDN issue the following command:

# hostname -f
server1.example.com

2.1. Configure domain name (Red Hat RHEL, Fedora and CentOS)

From these path add the parameters needs

vi /etc/sysconfig/network
DOMAINNAME=<domainname>

vi /etc/sysctl.conf
kernel.domainname = <domainname>

2.2. figure domain name ( Ubuntu, Debian)

#vi /etc/hostname
server1

Then restart the service:

Display OLED Arduino

Sun, 17 May 2020 00:00:00 +0000

On this post I’ll explaining how to setup a little OLED screen 128X64 on Arduino Leonardo

Tools:

Chit: Arduino Leonardo
Screen: Led OLED display 128x64 bought here
Workstation: Silverblue Fedora 33
Compiler: Arduino IDE

Over here you can see the connection diagram.

Steps:

Install the Arduino IDE from Flathub repo.
Now you have the flatpak Arduino app, below you will see older information related to a bug of the last Arduino Flatpak version, but now it fixed. Please continue with the 3th step.

~~2. Launch the Arduino IDE:~~

LineageOS 17.1 in Xiaomi A2 Lite (Daisy)

Fri, 03 Apr 2020 00:00:00 +0000

LineageOS17.1 in Xiaomi A2 Lite (Daisy)

The follow instructions are done by adb and twrp commands line.

OS used: Windows 10

Requirement:

adb fastboot tool
USB drivers
Xiaomi driver

Set into your android device:

USB debugging option enable.
Disable Encryption on the phone (DisableForceEncryption.zip)

Packages(download and leave the installation packages into your mobile SD):

LineageOS 17.1 for Xiaomi “Daisy”
TWRP
GApps

Press the dlower button + power button to boot in
Plug the mobile on your pc.
Open adb terminal tool (C:\Program Files (x86)\Minimal ADB and Fastboot\cmd-here.exe) and test it by: adb devices
Fastboot boot twrp.img –> in my case I use: twrp-daisy-3.3.1-0-offain.img it worked for my device :)
Make sure to create a backup (System, Data and Boot).
Then wipe the data partition, cache partition and the system partition (on this step you will lose all your data).

adb shell

twrp wipe data
twrp wipe cache
twrp wipe system

Install LineageOS17 image by TWRP commands and restart to TWRP mode again.

twrp install /external_sd/LineageOS17/lineage-17.1-20200413-UNOFFICIAL-daisy.zip
exit
adb reboot bootloader

Install Gapps (google play market)

adb shell
twrp install /external_sd/LineageOS17/BiTGApps-arm64-10.0.0-v0.6_signed.zip
exit

switch to slot if you are been in the A slot now switch boot onto B

fastboot getvar current-slot  --to know which slot you are
fastboot set_active b  -- If you were at A slot so switch to B
adb reboot

Below I left a couple of links were useful for me; I strong recommended to backup all your data before to start, as well as count with other phone in case you get in trouble with the installation.

Add your app into the Gnome Desktop Menu

Mon, 30 Mar 2020 00:00:00 +0000

I’ve been looking for a encryptation app open source, to encrypt my files into Cloud with a touch of off-online control, and I found this nice app called Cryptomator. I downloaded the extension .Appimage, so the following instruction I will explain is how to set the .appimage into the app menu in Gnome.

Download the Cryptomator by the link above.
Set the permission below:

#chmod a+x cryptomator-1.4.15-x86_64.AppImage

The try to execute the file by a shell terminal or just double click on it ( to confirm it was downloaded fined)

Repo-list

Sun, 08 Mar 2020 00:00:00 +0000

This is a documentation I’ve made time ago searching some open source tools and platforms(& freeware), I hope It can be useful to you:

Ticketing

https://www.graylog.org/ Monitoring / Open source

Discover and resolve issues faster. Keep end users happy with less downtime and better performance by proactively monitoring key indicators and exceptions across the entire stack.

https://www.happyfox.com/ Ticketing / private

Meet HappyFox, a practical help desk and customer support software solution. Reduce chaos and bring order to your support process with a robust support ticket system, self-service knowledge base and community forums.

SQL some concepts & notes

Mon, 24 Feb 2020 00:00:00 +0000

SQL Structured Query Language, is a language designed to allow both technical and non-technical users query, manipulate, and transform data from a relational database.

Some popular SQL databases:

SQLite
MySQL
Postgres
Oracle
Microsoft SQL Server

Relational database:

Represents a collection of related ( two-dimensional) tables.Each of the tables are similar to an Excel spreadsheet, with a fixed number of named columns and any number of rows of data.

DDL (Data Definition Language) refers to the CREATE, ALTER and DROP statements DDL allows to add / modify / delete the logical structures which contain the data or which allow users to access / maintain the data (databases, tables, keys, views…). DDL is about “metadata”.
DML (Data Manipulation Language) refers to the INSERT, UPDATE and DELETE statements DML allows to add / modify / delete data itself.
DQL (Data Query Language) refers to the SELECT, SHOW and HELP statements (queries) SELECT is the main DQL instruction. It retrieves data you need. SHOW retrieves infos about the metadata. HELP… is for people who need help.
DCL (Data Control Language) refers to the GRANT and REVOKE statements DCL is used to grant / revoke permissions on databases and their contents. DCL is simple, but MySQL’s permissions are rather complex. DCL is about security.
DTL (Data Transaction Language) refers to the START TRANSACTION, SAVEPOINT, COMMIT and ROLLBACK [TO SAVEPOINT] statements DTL is used to manage transactions (operations which include more instructions none of which can be executed if one of them fails).

Some SQL queries:

Docker Container "before start"

Sun, 26 Jan 2020 00:00:00 +0000

Part I

Containers are environments that host individual applications using a framework like Docker.

Docker Editions:

Docker CE ( community edition ) free version
Docker EE ( enterprise edition) Paid

Versions:

Stable, released every 4 months.
Edge (beta) released every month. For testing
EE, support for one year.

Example how to create a container:

$docker container run --publish 80:80 --detach --name webhost nginx

detach: subcommand is to let run the container and keep use the command prompt name: create a container’s name.

How to set you SSH key into Gitlab

Thu, 26 Dec 2019 00:00:00 +0000

How to set you SSH key into Gitlab [First you need to had installed Git onto your distro]

Go to your terminal and issue the follow command to generate your key: $ssh-keygen
Copy your public key from the route: /home/user/.ssh/id_rsa.pub
Then go at your gitlab profile https://gitlab.com/profile/keys/ a paste and save.
From the terminal test the conection by typing: $ssh -T git@gitlab.com and if everything was fine it has to promt –> Welcome to GitLab, @user_account!

How to create a docker-compose.service

Sun, 08 Sep 2019 00:00:00 +0000

Here are the steps I made to set a service into my Fedora server to start/stop my Docker-compose (Wikijs)

Why I decided to use a docker-compose into a Linux VM machine? —> for make it more stable, faster,portable, isolated, etc.

First I stared using Docker for Windows and it was a little bit unstable and not quite easy to handled, so when I switched to Docker compose into a Fedora VM and in that point it was a huge different(I do not recommend to use Docker in Windows); I use a Vmware hypervisor ( in the office we use it ).

Backup your Wikijs DB

Mon, 15 Jul 2019 00:00:00 +0000

This is a little resume of how I’m doing a backup procedure of my wikijs database based in Docker-compose.

Below are the systems used in my enviroment:

Project: Wikijs 2.0 Beta
Platform: Docker-Compose
DB: Postgres (9.6.14)
Server: Fedora Server 30.x86_64
Workstation: Windows 10 (provided by work) 😬

PSQL basic commands:

Here are 4 basic commands I use to connect into my Postgre DB and check out DB list and quite.

$psql -h localhost -p 5416 -U <my-user> -d <my-database>

Create a .zip using 7z by cmd in Windows

Tue, 11 Jun 2019 00:00:00 +0000

After to install the 7z in our windows workstation/server then we need to create our evironment variables to call the function from the cmd [1].

Then the command below will guide you to zip a simple file:

7z a -r [myzip] [example.txt]

[myzip] - the zip name file
[example.txt] file used for the example

To zip a folder

7z a [myzip] [folder]

Docu based thx to the information seen from: [1] GlobalEnviroment

Closing opened ports on Linux (Fedora 29)

Sun, 05 May 2019 00:00:00 +0000

Using the Nmap to list our opened port in our machine, how described the official website: Nmap “..is an utility for network discovery and security auditing..”

Regarding CUPS from the official website: “is an open source printing system developed by Apple Inc. for macOSÂ® and other UNIXÂ®-like operating systems. CUPS uses the Internet Printing Protocol (IPP) to support printing to local and network printers.”

By default we have the cups service running in the system’s startup we could check out issue the following commands:

Output IPCONFIG report to HTML by PowerShell

Thu, 25 Apr 2019 00:00:00 +0000

$file = "C:\Users\jcr\a.html"
$ipconfig=ipconfig /all |%{"$_<br/>"}

$body=@"
<html>
    <head>
    <title>Network Report</title>
    </head>
<body>
    <h1>IPConfig /All</h1>
    <pre>$ipconfig</pre>
</body>
</html>
"@
$body | Out-File $file
. $file

Setup Grafana in Raspbian (Raspberrypi)

Tue, 09 Apr 2019 00:00:00 +0000

The below post is a simple explanation I did time ago, if you want further info and better explanation about how to setup a monitoring system into your Raspberripy please go to here.

Raspbian version:9.8

$ uname -r
4.14.98-v7+
$ uname -m
armv7l

Version installed on my RasPi: Grafana v6.0.2 (3f4c2e7)

Download Grafana package for your correct Raspi ARM
$sudo dpkg -i grafana_6.1.3_armhf.deb
$systemctl start grafana-server
$systemctl status grafana-server
then you will see from the status propmt the address=0.0.0.0:3000

msg="HTTP Server Listen" logger=http.server address=0.0.0.0:3000

To check the site is working go through localhost:3000

Create a job using crontab

Wed, 03 Apr 2019 00:00:00 +0000

To automate tasks or create some monitoring job we can use the older and efficient tool the “CronJob”.

For our example, I’ve created a simple script to detect the cache memory and clean it if raise to a condition then send a notification by mail.

Library used:

exim4 (mail server) or ssmtp (mail server). Both uses the same “mail” command.

Script:

# grab the buff/cache memory
mem="$(free -m | grep 'Mem:' | awk '{print $6}')"

if  (( $mem > 350 ))
then
echo 'wooo is more than 250M'
echo 3 | sudo tee /proc/sys/vm/drop_caches
echo 'cache dropped'
echo "Memory buff/cache cleaned last value:" $mem | mail -s "cache_memory" target_mail@local.com
else
echo 'be cool man, memory lower'
fi

script path: /user/Documents/script/memory

Parsing date format from .xlsx to R

Mon, 01 Apr 2019 00:00:00 +0000

Version:

platform x86_64-redhat-linux-gnu
arch x86_64
os linux-gnu
system x86_64, linux-gnu version.string R version 3.5.3 (2019-03-11)

Library

lubridate

Parse method

—————————— as.factor ——————————

mydata$FECHA_NACIMIENTO<-as.factor(mydata$FECHA_NACIMIENTO)

—————————— variable for strptime ——————————

tempo<-strptime(mydata$FECHA_NACIMIENTO,"%d/%m/%Y")
mydata$FECHA_NACIMIENTO<-as.Date(tempo,"%d/%m/%Y")

—————————— clean variable ——————————

rm (tempo)

mydata$FECHA_NACIMIENTO <- format(as.Date(mydata$FECHA_NACIMIENTO), "%d/%m/%Y")

—————————— parsing data ——————————

library(lubridate)
mydata$FECHA_NACIMIENTO <-dmy(mydata$FECHA_NACIMIENTO)

Disable live-restore to run Docker Swarm

Thu, 28 Mar 2019 00:00:00 +0000

The following instruction is a solution when you got an error response with live-restore using Docker Swarm in Fedora 28 or highter

$ docker swarm init
Error response from daemon: --live-restore daemon configuration is incompatible with swarm mode

That’s not possible to enable Live-restore and Swarm-mode together.

First make sure that the SElinux is Permissive or Disabled.

$ sestatus

SELinux status:                 enabled
SELinuxfs mount:                /sys/fs/selinux
SELinux root directory:         /etc/selinux
Loaded policy name:             targeted
Current mode:                   permissive
Mode from config file:          enforcing
Policy MLS status:              enabled
Policy deny_unknown status:     allowed
Memory protection checking:     actual (secure)
Max kernel policy version:      31

Then remove the –live-restore line from the /etc/sysconfig/docker

Pulling Mysql using Docker Hub into Linux workstation

Thu, 28 Mar 2019 00:00:00 +0000

$ systemctl start docker
$ systemctl status docker
$ docker pull mysql
$ docker image ls
$ docker run --name db -e MYSQL_ROOT_PASSWORD=mysql123 -d mysql

Use the docker exec -it command to start a mysql client inside the Docker container you have started, like the following:

$ docker exec -it db mysql -uroot -p

Enable "Kubectl" auto-completion in the Shell (Linux)

Sun, 25 Nov 2018 00:00:00 +0000

When you’ve done the SDK installation in your Linux workstation. list the components you have installed, then you will see the full list additional components from gcp SDK:

gcloud components list
gcloud components install <COMPONENT_ID>
gcloud components install kubectl

Then follow the instruction from the kubernetes official documentation, check the “bash-completion” and finally issue the command below:

echo "source <(kubectl completion bash)" >> ~/.bashrc

Even you can go directly through your .bashrc (sudo) to add manually, it should look like:

About

Mon, 01 Jan 0001 00:00:00 +0000

Hello there! I’m a big fan of GNU/Linux 🐧 and all things open-source. By day, I work as a DevOps 👨‍💻, wrangling various projects to ensure they run like well-oiled platform. But let me take you back to where my journey began - coding in Assembly language and tinkering with MicroChip, Atmega and embedded devices. That was my playground before I took the leap into the cloud, focusing on CI/CD, GitOps, SRE, and HA zones, my main focus it’s to delivers reliable IDP.