Development on Abel World

Docker master slave MySQL replication

Tue, 11 Dec 2018 09:45:37 +0200

Docker master slave mysql replication can be a bit intimidating, but the basics are actually quite easy, just a bit of a laborious work. As of this example I will use docker swarm. for that I assume you have docker already installed fresh on the machine. My example uses CentOS 7.6, but should be similar on other systems like ubuntu. Enjoy the post!

Get the mysql image:

docker pull percona:5.7

Create a few dirs to hold the structure:

Two separate folders for master and slave.
The cnf directory has the configuration files for mysql
The data directory has the volume of mysql structural data.
The folders called mysql, performance schema and sys should NOT be created. those are done by MySQL server on start.

MySQL slave master switch

Sat, 01 Jul 2017 17:15:11 +0200

MySQL slave to master switch is an operation required in a few situations. Sometimes master dies and you need to make DB available as soon as possible. In this case if the DB is reasonably big then restoring from backup might take to long. Also keep present that slave has a current copy of data, you might have new data after the last backup that you can not afford to lose. Some other common situations where you might require such a procedure is when you want to upgrade your MySQL servers. For instance from Percona 5.6 to Percona 5.7. Also this will help to avoid long downtime.

Notice: if you have classic master slave replication some downtime is unavoidable, there are different setups that can be done to achieve having a cluster that does not stop working if you take the master offline, but this is NOT the objective of this post.

this post is some what related to another recent post; Mysql DB server OS change / replacement or distro upgrade; study case

Ok, let’s stop the chitchat and let’s get some stuff done.

Hosting network services services and websites basics

Thu, 12 Nov 2015 19:47:53 +0200

Hosting network services and websites or blogs like this one is now a days a regular task of anyone who want to conduct a successful business. This is non written a requirement for many other activities as well. If you are not an ICT professional and you have a website or need to deploy some services in your business and you wander where to store them and how. Then this article is for you.

More people than you might think want to get a server at their home or office and host their own websites and services locally. I am not 100% against this type of solutions, but the truth is the all the odds now a days are against it unless you have a particularly special need to have it locally. Let see what are the drawbacks.

Website development projects

Thu, 05 Nov 2015 19:39:13 +0200

Having a good Website is very important for modern business, so some of the last projects that I have been doing lately are related to website development. For instance one of them were done for Team Engineers (Pty) Ltd, Botswana. They already had a website, that needed a platform easier to edit and manage as well as a new look to certain extend and some interactive features. Team Engineers defines itself as follows.

“TEAM Engineers (PTY) Ltd. is a specialist prefabricated accommodation solutions provider. Since its establishment in 1997, TEAM has gone from strength to strength not only in capacity and knowledge, but also in diversity of the product range and our level of service.”

They are the biggest company in Botswana in the business with a very well gained reputation of great quality solutions, for diverse purposes like: accommodation, mining facilities, schools, hospitals, offices, housing, etc. Please check out the next slider for some basic details about the look of the current website.

Web hosting administration software free alternative.

Thu, 29 Jan 2015 10:35:17 +0200

Hi, have engaged myself on a quest to look for an administration panel for my customers hosting. I want a good one to have it as an alternative to

Web Hosting

cPanel, the truth is that every day I like the cPanel project less and the free alternatives are getting better. So unless you are committed for some MAJOR reason to cPanel I would not recommend it any more. Use any other GLP like thing from out there, if the problem is support get better support from one of the communities.

Update multiple tables from a column; MySQL

Tue, 27 Jan 2015 12:03:13 +0200

Update multiple tables from a column is something that does not happen very often. Personally I never had to do it. I came across this question from a friend. He is programming something, and he had the following situation:

field_data_body
+----------+---------------------+
| entry_id | body_value |
+----------+---------------------+
| 1009 | content |
+----------+---------------------+
| 1020 | |
+----------+---------------------+
| 1025 | more content |
+----------+---------------------+


i_posts
+------+---------------+
| id | html |
+------+---------------+
| 1009 | |
+------+---------------+
| 1020 | | 
+------+---------------+
| 1025 | | 
+------+---------------+

From this two tables he wanted to get i_posts updated with information from field_data_body’s body_value field. In other words write this:

Synchronization GLPI LDAP or Active Directory

Mon, 12 Jan 2015 23:27:46 +0200

Synchronization GLPI LDAP. GLPI is a very popular ticket (call) system. It has a lot of features that make it competitive with any other ticketing or ICT management system. Some of the features that I have configured before are here.

LDAP Active Directory Connection.

One of the many powerful features of GLPI is the integration with many forms of LDAP. Among them Windows Active Directory (AD). To integrate it you just have to supply your AD server info on the form shown on this picture.

LDAP AD config

If you receive any error about not finding any configuration. You might have the PHP LDAP module missing. So make sure the module is installed.

Host LDAP is the address of the server (AD or Openldap) that glpi will use.
Basedn is the field that identifies the DN (Distinguished Name) where the search is starting.
rootdn (For non anonymous connections): this is for the user authorized to read the Directory (AD or Ldap for example: cn=Admin,ou=People,dc=mycompany make sure not to leave spaces between nodes. This is wrong: cn=Admin, ou=People , dc…)****
Pass (For non anonymous connections): User password.
Connection filter: To restrict the search.

Hits, visitors, challenges and achievements; Abel world

Fri, 09 Jan 2015 17:56:16 +0200

Visitors, my personal blog is more than one year now. During this time I managed to achieve a few things 🙂 and

Pic. 1 – Today’s visits per country.

some others not so well. As an ICT professional this was my first adventure with having my own blog. I have been in the field for many years. Mainly doing other types of works. Like network administration, developing software and websites, etc. Never before I have started my own web. Never tried to maintain a my own web to make it succeed.

before starting to explain the results fist let me tell you the objectives of creating the web. When I created my blog I wanted to:

Learn English by writing and being corrected by people.
Create sort of a logbook of some of the work I do.

So far I have half won half lost. Let me put the list of failures first.

My web is not a hit like Facebook. It would be good to have something like that and become a million-er. But it just did not happen. It was not one of my objectives and my subjects are not so general. I have not put enough time on this web. in general I did not manage.
I still have a lot of English to learn, and I think I am a bit dyslectic. I am serious! I write things and I think they are fine. Then review a few times. Everything is perfect. Give it to someone to read and he finds that I made a lot of mistakes like forgetting about letters or changing them. Let say I write “in” when I wanted to write “is”. About the English improvement, if you read my fist posts you will see for your self. For instance check out this one.
My website cost is payed from my own pocket, it does not pays it self yet. But soon it will.
I have not been able to really put all the time I wanted in to the site.

The good things:

Network segmentation for business

Thu, 08 Jan 2015 19:55:09 +0200

Network segmentation was created to help dividing network from each other. Wikipedia defines it as: “Network

Network Segmentetion

segmentation in computer networking is the act or profession of splitting a computer network into sub-networks, each being a network segment or network layer. Advantages of such splitting are primarily for boosting performance and improving security.”

The applications of this are infinite in now a days business world. Let me just explain a little about my customer particular case.

I decided to write this Network segmentation post due to our last client. He is a hotel owner. The hotel has a lot of rooms. They had a network of a few staff computers plus all the customers computers. The customers access the network using WiFi. Just to serve as an example the customers were on the same network as the accounting computer. That is not a good idea. For instance the day that I was deploying the server at the hotel. I had to cut the network for a few minutes. A customer came to complain and guess what. He was an IT guy. He came saying to me things like the IP address from today is different from the one I had yesterday. I did an NSLOOKUP and it says bla,bla,bla. This guy turned to be a really nice guy, but not everyone has a good heart and intentions.

So because of an incident the owner called me to find a solution. He wanted a few more things. Here is part of a presentation we did for him.

GLPI ticket system & Inventory solution a very viable solution

Tue, 06 Jan 2015 16:00:10 +0200

Team work organization solutions with GLPI

Have a problem to organize team work? have problem to document and follow performance? You do not have satisfactory the statistics about the work done! Have you ever had problems to find simple reports like who is the best worker of the month? Have problems planning resources for the department? Do not know how many computers and other equipment are in the network?

You can use GLPI to solve all those problems. I have a few years of experience maintaining these type of servers for different environment and customer needs. lso I decided to write this post and share some of the things that you can get with GLPI. The main features of GLPI are:

Inventory of computers, peripherals, network printers and associated components through an interface with OCS Inventory or FusionInventory.

Management of issues on many environments through creation of tickets, management of tickets, assignment, tickets scheduling, etc.

Licenses management (ITIL compliant)

Assignment of equipment by geographical area to users and groups

Management of business and financial information (purchase, guarantee and extension, damping)

Equipment status management

Management of applications for assistance of all types of equipment inventory

Interface to allow the user to file a support ticket

Business management, contracts, documents related to inventory items

Equipment booking

Management of a Frequently-Asked Questions (FAQ).

Report generator: hardware, network or interventions (support).

Multilingual support with 45 languages available.

Git client configuration for a local server.

Fri, 04 Jul 2014 18:03:31 +0200

Gitlab Logo

Configuring a git client can be painful sometimes if you are a beginner. I struggled the first time I configured git too. So I am creating this material for others like me to be able to configure git. I hope it works for you. Git is now a days one of the most popular versioning systems. I use git since a few months ago to keep my Symfony 2 projects update.

Configure gitclient with you User name:

git config --global user.name "Abel Guzman"

VirtualBox Virtual machine in Linux- Class 7

Tue, 13 May 2014 09:15:31 +0200

Virtualbox is today’s posts subject . We will talk about virtualization and how to virtualize a box using Virtualbox. To start we need to know what is virtualization and its advantages.

virtualbox logo

Virtualization, in computing, refers to the act of creating a virtual (rather than actual) version of something, including but not limited to a virtual computer hardware platform, operating system (OS), storage device, or computer network resources.

Taken from: http://en.wikipedia.org/wiki/Virtualization on 2014-04-22.

This post is part of a bigger Debian material that you can access here.

Fleet management system with Symfony 2, php, MySQL; TeamERP Transport

Tue, 15 Apr 2014 10:27:55 +0200

TeamERP Transport Symfony 2

Updated on 2014-05-19.

I have been programming for one week and I have a transport module that can work for different situation now. I have released it as a MIT license so that any one can use it or do what ever they want with it. My objective is to create a truly free ERP system. But you have to start somewhere, and I have decided that the transport module could be a nice module. This module is a software that can be used to record transport expenses and to follow the cars movements. It’s not a tracking systems. but in the future I an planning to integrate it with one of this projects. the project was developed with Symfony 2; php, MySQL.

In this document I described the Symfony 2 development process for the development of a Fleet management system. I started from scratch to what I currently have and it took me one week of work. The project is going to be used by a friend of mine company. All the iterations and problems found along a real life development process will be posted here. This document is about the Transport module and the objective is not to have a book of how to use Symfony 2 and develop. But a guide of what has been done with Symfony 2 and the current state of the module. More like a diary of notes and the documentation of this development. You can also find some other Symfony 2 development material here.

Apache 2 web server; install and config a virtual host

Tue, 08 Apr 2014 11:08:07 +0200

Good day; today we will install a web server using Apache 2. We will specifically use apache because there are many web servers out there, and apache is probably the most popular one even among windows users, when you install Wamp Server, or Xamp,

Apache Web Server

you are also installing apache 2.x. It has some other advantages or benefits like Openness, a lot of features, extensibility, portability, cost, simple administration, reliability, flexibility, etc. Check out this link for some explanations. It has also some downsides or disadvantages like for instance; it’s Written By Geeks, For Geeks. That does not mean is difficult or any thing like that, but it can be twisted for some specific situations.

The Linux philosophy to install a software like Apache 2 is different from Windows. Windows tries to solve all of your problems at once, Linux’s philosophy is to solve only one of your problems using the best practices. Each of this ways of thinking has it pros and cons, but that is not the objective of this class, so we move on.

To install the package you have to do:

aptitude install apache2

Symfony and WAMP 2.4 windows installation

Tue, 11 Mar 2014 16:05:24 +0200

To work with Symfony, many people recommend to install every thing as a separate entity; PHP, Apache and MySQL. But sometimes the reality is different and you just need to use what you need to use. That was my case. I had WAMP Server 2.4 working for WordPress and I neded to install a Symfony 2.4 project, no option. So I decided to just meet the Symfony dependencies and install it. Then I created a cert of manual or how to? to help to guide others that might have the same problem. Also you might want to do it because of some other reason, but that was my reason. I was requested to do it like that and only like that. And in my country we have a saying that teaches something like this. If someone wants something even if it is a bad thing; don’t give him other thing. Of course I do not mean that WAMP or Symfony together are a bad thing. This is what I have done:
Software to install:

Linux Server Classes (Introduction)

Thu, 27 Feb 2014 14:39:18 +0200

Linux Server Classes; About this group of materials.

Linux Versions with Tux

I have started this post to bring Linux classes to any one in Gaborone, Botswana. Also you can access and use this materials any where else in the world. The only conditions is that you have to be willing to learn new and useful stuff from the free software movement. This Linux skill sharing was done for the ICT staff in Princess Marina Hospital in Gaborone, Botswana. The main objective was to socialize the Linux knowledge. These skill sharing classes are not part of any certified course. They are just the product of the personal experiences of a Linux and windows network administrator. Linux is currently being used at the hospital in most of the servers and a few workstations. But the course is thought as a General introduction to networking using GNU Linux Debian.

Odoo specialist wanted.

Sun, 23 Feb 2014 07:35:12 +0200

Odoo/OpenERP Developer wanted. We need someone to create custom open source modules on request, modify workflows and templates as well as some other minor jobs.

Please provide samples of works, rates and references.

Please contact me with the information required and we will come back to you.

Closing date: February 15, 2015

Crystal Reports and Java expert needed

Sun, 23 Feb 2014 07:28:15 +0200

We need a crystal reports specialist to work as a consultant on some project for one of our best customers. They have an ERP system done in java with reports in Crystal Reports. They want some extra custom reports, so the main task is going to be related to the reports and not java programming but could also be included. Basically they will send the reports wanted once we have the specialist. Please send me the works you have done related to Crystal reports and having some Java knowledge is a plus and some references also send your hourly rate or some figures about how would you change for your job. We need someone able to spend time to understand the customer requirements and complete the work from A to Z.

Retirement Advisory System (RAS)

Mon, 25 Nov 2013 09:58:34 +0200

RAS acronim for Retirement Advisory system is a free software distributed under MIT license. This software is currently used in Princess Marina Hospital to assist the Terminal Benefits Department with the Retirement of workers. Check out the github repo here.

Animate on linux command prompt gif

Mon, 18 Nov 2013 17:42:02 +0200

To Animate images (even simple ones) sometimes difficult to achieve, and not every one has 700.00 USD to pay for the adobe products or you just do not want to pay 20 USD for adobe cloud for a simple animation. Here you can find a note to know how to create .gif animation from the command prompt in linux (in my case Debian).

CSS 3 to style a Symfony 2 project

Mon, 11 Nov 2013 16:34:32 +0200

CSS 3 and Symfony 2

Symfony 2 and CSS 3 is the subject of this how to. Styling a project can make the difference between buy or not to buy. so even if you have the best functional application, you need to css style it nicely to be able to attract people to it. We will go through styling your project from ground and also some additional tips that I have learn along my day to day work with Symfony 2.

GLPI for technical support, the free tickets System.

Sat, 09 Nov 2013 10:34:41 +0200

GLPI Statistic Charts

GLPI is a free Tickets System distributed under GNU/GPL license. But When do you need a ticket system like this? This is one of the biggest challenges of the technical support companies or technical support teams. If they have to deal with many customers and the response times are critical. To be able to track, follow and organize the work of the different technicians that are supposed to do the actual job. In this scenario the paper work always becomes a challenge, accessibility, loose of information, spell and writing errors, individual and collective statistics, reporting, etc.

Useful Notes as a solution to punctual problems

Fri, 08 Nov 2013 18:20:21 +0200

I tend to forget where I find the solution for my problem very often, so I will start recording some of the solutions that I find for my different problems, if any one find this list some how interesting or useful in the future please consider leaving a comment or suggest other useful information that you have found in internet:

GPS tracking; a Business automation Solution

Fri, 25 Oct 2013 08:45:33 +0200

GPS Tracking; this is the first of a few articles about business automation solutions. I try to suggest a stable but also as affordable as possible. This can be implemented by business that might not have enough to pay for a tracking company or just do not want to do it and they want to have their own tracking system.

Symfony 2 hosting server

Wed, 09 Oct 2013 06:54:35 +0200

Symfony again! Hello, as you know I like to hit my head against the screen from time to time. So today I’m going to try to configure a server to host Symfony Aplications. The host in this case will be a virtual machine in my own computer.

Note: this post is about how to install Symfony, how to meet the requirements. if you have done this already maybe what you need is to deploy your product app. visit this link for that . And if you want to install in windows you can follow this link

My OS is a Debian testing (8) and I have a virtualbox running ready to have a lot of virtual
machines. So I have created a Debian Stable (7) Virtual Machine that will be our server for the symfony 2 applications. in this case I’m going to use Symfony 2.3.5 the latest version available on the server. I am talking to much take a look at the image of my of my VM for more information.

Symfony 2 production environment server deploy

Mon, 07 Oct 2013 07:26:43 +0200

Symfony 2 logo

Symfony 2 is one of the most popular PHP frameworks and particularly my favorite. My fist time to deploy a project in production environment, I have struggled a lot. One of the most common errors you might get when you execute the prod environment is “401 Page Not found”. But, actually it is really simple to make a Sysfony 2 project work. you just have play a little bit around with it knowing what you want.

Siwapp online invoicing

Wed, 18 Sep 2013 14:57:10 +0200

Siwapp is a free invoicing software. It has friendly web environment that lets you install it on a local computer and also in internet or other network server. It is not a secret that for small and medium size business one of the biggest overheads many times is money that is spent on computers software.

My Telephone Directory

Thu, 05 Sep 2013 17:35:59 +0200

My Telephone directory 2013 is a free software that it is been created to manage organizations telephone directories and people information. It was originally designed for Princess Marina Hospital in Gaborone, Botswana. But thinking about a general solution for any businesses and organization. The solution is able to store useful information for the personal that works withing an organization or that needs information about the personal on the organization. It stores data like names, phones, e-mails, fax, departments, designations and much more. Every thing accessible from a web browser on a desktop, tablet or smart phone just with a couple of clicks.

Slider and gallery wp

Fri, 16 Aug 2013 09:34:37 +0200

OUT DATED POST

I needed a Slider and gallery of images using WordPress as it is my preferred development CMS because WordPress is very popular all over the world for several reasons. It’s easy to manage in beginner level, there is a lot of documentation and there is a huge community supporting new comers, but for more information you can check here or do your own research in Google.

Read the content of a word document with PHP.

Mon, 12 Aug 2013 14:21:30 +0200

Today we will try to read a word document with PHP, and when I say read I mean take the text in the document and extract it.

First we create this function:

<?php
    function read_file_docx($filename){

        $striped_content = '';
        $content = '';

        if(!$filename || !file_exists($filename)) return false;

        $zip = zip_open($filename);

        if (!$zip || is_numeric($zip)) return false;

        while ($zip_entry = zip_read($zip)) {

            if (zip_entry_open($zip, $zip_entry) == FALSE) continue;

            if (zip_entry_name($zip_entry) != "word/document.xml") continue;

            $content .= zip_entry_read($zip_entry, zip_entry_filesize($zip_entry));

            zip_entry_close($zip_entry);
        }// end while

        zip_close($zip);

        //echo $content;
        //echo "<hr>";
        //file_put_contents('1.xml', $content);        

        $content = str_replace('</w:r></w:p></w:tc><w:tc>', " ", $content);
        $content = str_replace('</w:r></w:p>', "\r\n", $content);
        $striped_content = strip_tags($content);

        return $striped_content;
    }

?>

Second we use the function:

Child Theme Wordpress

Sun, 04 Aug 2013 18:38:23 +0200

Well today I’m going to explain how to create a child theme in WordPress is kind of simple work, but some of us had to struggle to get it done when we started to do our first WordPress sites (by we you my understand ME), because the true is that is very easy now that I know.

Responsive child theme

Basically what you have to do is to go to /wp-content/themes/ create a folder with the name of the child theme (different from other themes you have) for instance “sosolar”. Inside this folder you can create any structure on a theme, but the only file required is “style.css”, then you only have to create a special content for this file.
The file is supposed to have inside the following:

Path links menu; Wordpress browsing

Wed, 31 Jul 2013 13:39:46 +0200

I have used the theme Twenty Eleven a couple of times as the father theme for my web creations, and it works for me very well, but sometimes when the website grows to much with a lot of contents and several child pages; while users are browsing, they might get confused; due to the default absence of path links in most WordPress themes, sometimes happens after the user goes inside the menu and clicks on a few links they don’t know where are they, so a functionality that shoes the path to the page where you are is very useful sometimes.