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"That was an out-of-body experience. It was like God was coding through me. Time stood still.", by Dinesh Chugtai (Kumail Nanjiani) in series Silicon Valley

Simlinks, hard links and junctions in Windows
Development

Simlinks, hard links and junctions in Windows

Simlinks: There is really only one directory or file in storage, and the link. The space required is not doubled.It is a direct access to a directory or fileIt can be done

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
1 min read
JavaScript and its execution engines
Development

JavaScript and its execution engines

A JavaScript engine is a tool that executes JavaScript code.There are two types of JavaScript engines from the point of view of operation: runtime interpretes JIT: just-in-time compilation Runtime interpreters have less

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
2 min read
Scopes and declaration of variables with var, let and const in JavaScript
Development

Scopes and declaration of variables with var, let and const in JavaScript

In JavaScript there are two main scopes where to locate the variables, and these scopes determine the accessibility to these variables:* global * local: no están accesibles desde el scope global A variable in

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
2 min read
openssl - Linux man page with examples: example with command s_client and options showcerts, servername y connect
Development

openssl - Linux man page with examples: example with command s_client and options showcerts, servername y connect

Example with the command 's_client' of openssl to see the certificates of a domain. With the 'connect' option we specify the IP or DNS of the server we want to consult, the

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
5 min read
openssl - Linux man page with examples
Development

openssl - Linux man page with examples

NAME openssl - OpenSSL command line tool SYNOPSIS openssl command [ command_opts ] [ command_args ] openssl list [ standard-commands | digest-commands | cipher-commands | cipher-algorithms | digest-algorithms | public-key-algorithms] openssl no-XXX [ arbitrary options ] DESCRIPTION OpenSSL is a cryptography toolkit implementing

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
11 min read
Using curl: proxy calls with user and password to URLs with basic authentication
Development

Using curl: proxy calls with user and password to URLs with basic authentication

The way to use curl for calls to a URL that have basic authentication through a proxy with per-user authentication and password is as follows:curl -v -o /dev/null -x http://myproxy.

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
4 min read
How to implement an angular custom pipe in a JHipster application
Development

How to implement an angular custom pipe in a JHipster application

Let's detail the steps to create a custom pipe in a JHipster 6.10.5 application with angular 10.0.0.We will define a pipe that converts a string into a kebab-case

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
3 min read
How fix errors "No X11 DISPLAY variable was set" and "An error occurred: Can't connect to X11 window server using 'x.x.x.x:0.0' as the value of the DISPLAY variable" in ssh sesion with X11 forwarding
Development

How fix errors "No X11 DISPLAY variable was set" and "An error occurred: Can't connect to X11 window server using 'x.x.x.x:0.0' as the value of the DISPLAY variable" in ssh sesion with X11 forwarding

I use Windows 10 as a working operating system but almost all the development operation and system architecture is done through Ubuntu and CentOS computers that I access by ssh, VNC or RDP

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
5 min read
How to install kubectl with multiple versions to be able to manage different versions of kubernetes cluster with update-alternatives on ubuntu 20.04
Development

How to install kubectl with multiple versions to be able to manage different versions of kubernetes cluster with update-alternatives on ubuntu 20.04

I work with several clusters of kubernetes and each of it is of a specific version, therefore I need to have different kubectl. To manage this what I do is access https://github.

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
4 min read
Avoiding unexpected errors: 
sudo with meta characters like asterisk, question mark and others
Development

Avoiding unexpected errors: sudo with meta characters like asterisk, question mark and others

When a command is executed with 'sudo' the metacharacters except the $ are escaped. This causes that command like the following that we think should work correctly gives unexpected problems:sudo ls -t /etc/

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
1 min read
How to add to apache2 on Ubuntu 20.04 a new site configured to avoid cross domain errors using ProxyPass and ProxyPassReverse
Development

How to add to apache2 on Ubuntu 20.04 a new site configured to avoid cross domain errors using ProxyPass and ProxyPassReverse

In apache2 on Ubuntu, for example 20.04, if you want to add a new site or configuration for a site you must first define the site in a configuration file to be

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
3 min read
How to update node with npm and the "n" module
Development

How to update node with npm and the "n" module

Whenever I have to update the node version I do it using npm along with module "n" although there are other options, but this one seems to me the most comfortable.Before upgrading

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
1 min read
How to fix the Error: EACCES: permission denied, unlink '/usr/local/bin/jhipster' when installing generator-jhipster library node with npm
Development

How to fix the Error: EACCES: permission denied, unlink '/usr/local/bin/jhipster' when installing generator-jhipster library node with npm

I found this error when creating a jhipster project with npm, and first trying to install the node generator-jhipster library with:npm install -g generator-jhipster The error detail is as follows:[operatorfeitam@dev01

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
5 min read
How to allow access to the jBPM Git repository from a network interface other than localhost
Development

How to allow access to the jBPM Git repository from a network interface other than localhost

The jBPM 7.43.1 Git repository only serves localhost by default. If you have the jBPM server on a machine other than where you are developing, it is required to enable this

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
2 min read
How to create a new maven archetype
Development

How to create a new maven archetype

I am in a project that requires the use of jBPM and the technical approach is to have the different BPM processes deployed in containers. This forces me to generate many jBPM applications

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
12 min read
Error installing eclipse on CentOS 8: No protocol specified. Unable to init server: could not connect: connection refused. Eclipse Installer: cannot open display
Development

Error installing eclipse on CentOS 8: No protocol specified. Unable to init server: could not connect: connection refused. Eclipse Installer: cannot open display

If you are installing Eclipse on CentOS 8 and you encounter this error:/home/operatorfeitam/Downloads/eclipse-installer [root@localhost eclipse-installer]# ./eclipse-inst No protocol specified Unable to init server: Could not connect: Connection refused

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
2 min read
Error while doing mvn install of nifi-1.11.4: Could not resolve dependencies for project ... was cached in the local repository, resolution will not be reattempted until the update interval of splunk has elapsed or updates are forced
Bugs and errors fix

Error while doing mvn install of nifi-1.11.4: Could not resolve dependencies for project ... was cached in the local repository, resolution will not be reattempted until the update interval of splunk has elapsed or updates are forced

I am compiling nifi-1.11.4 with "mvn -T C2.0 clean install -Pinclude-grpc -DskipTests" to parse a problem I am having in the connectivity of the ListSFTP processor with an SFTP service

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
3 min read
Maven error with jetty:run java.util.ServiceConfigurationError: org.apache.juli.logging.Log: org.eclipse.jetty.apache.jsp.JuliLog not a subtype
Development

Maven error with jetty:run java.util.ServiceConfigurationError: org.apache.juli.logging.Log: org.eclipse.jetty.apache.jsp.JuliLog not a subtype

The other day I found myself in a java project that was running locally with the jetty-maven-plugin and JDK 11.0.5, and it generated the error:[WARNING] Failed startup of context o.

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
5 min read
How to reduce the size of the .git folder
Development

How to reduce the size of the .git folder

In my projects I see that many times the .git folder grows too much and you can reduce it if you require spaces or consider it excessive.To reduce it by reorganizing all

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
1 min read
Use of avro-maven-plugin with complex schemas defined in several files to be reused in different typed messages
Development

Use of avro-maven-plugin with complex schemas defined in several files to be reused in different typed messages

In a project I am working on we integrate the different products with kafka and use avro. And to facilitate the generation of avro entities in java with their attributes and methods we

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
9 min read
How to change the language of google search results
Development

How to change the language of google search results

Today I found that the results of Google searches appeared in a different language than what I had configured in the browser and on my computer. It also appeared in my searches both

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
1 min read
Error: Couldn't find the 'yo' binary. Make sure it's installed and in your $PATH
Bugs and errors fix

Error: Couldn't find the 'yo' binary. Make sure it's installed and in your $PATH

Installing Yoeman in a CentOS 7,with the root user, and with the command 'npm install -g yo' I got the following error:[root@localhost ~]# npm install -g yo npm WARN deprecated cross-spawn-async@

  • Juan Luis Sánchez Vázquez
    Juan Luis Sánchez Vázquez
2 min read
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