Tag Archives: Jenkinsfile

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:



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

It is open for everybody.


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:


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


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. :)


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:



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.


Open Source from Carles


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. :)


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


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 Jenkins configurations for your projects

Obviously for companies is a must, but if you work in your own projects, it will be super great that you configure Jenkins, so you have continuous feedback about if something breaks.

I’ll show you how to configure Jenkins for several projects using only your main computer/laptop.

Check my past article about setting up Jenkins in Docker.

Adding a new Freestyle project

Click on top left: New item.

Then give it an appropriate name and choose Freestyle Project.

Take in count that the name given will be used as the name of the workspace, so you may want to avoid special characters.

It is very convenient to let Jenkins deal with your repository changes instead of using shell commands. So I’m going to fill this section.

I also provided credentials, so Jenkins can log to my Gitlab.

This kind of project is the most simple and we will use the same Docker Container where Jenkins resides, to run the Unit Testing of our code.

We are going to select to Build periodically.

If your Server is in Internet, you can active the Web Hooks so your Jenkins is noticed via a web connection from GitLab, GitHub or your CVS provider. As I’m strictly running this at home, Jenkins will be periodically check for changes in the repository and do nothing if there are no changes.

I’ll set H * * * * so Jenkins will try every hour.

Go down and select Add Build Step:

Select Execute shell.

Then add a basic echo command to print in the Console Output, and ls command so you see what is in the default’s directory your shell script is executing in.

Now save your project.

And go back to Dashboard.

Click inside of Neurona.cat to view Project’s Dashboard.

Click: Build Now. And then click on the Build task (Apr 5, 2021, 10:31 AM)

Click on Console Output.

You’ll see a verbose log of everything that happened.

You’ll see for example that Jenkins has put the script on the path of the git project folder that we instructed before to clone/pull.

This example doesn’t have test. Let’s see one with Unit Test.

Running Unit Testing with pytest

If we enter the project CTOP and then select Configure you’ll see the steps I did for making it do the Unite Testing.

In my case I wanted to have several steps, one per each Unit Test file.

If each one of them I’ve to enter the right directory before launching any test.

If you open the last successful build and and select Console Output you’ll see all the tests, going well.

If a test will go wrong, pytest will exit with Exit Code different of 0, and so Jenkins will detect it and show that the Build Fails.

Building a Project from Pipeline

Pipeline is the set of plugins that allow us to do Continuous Deployment.

Inform the information about your git project.

Then in your gitlab or github project create a file named Jenkinsfile.

Jenkins will look for it when it clones your repo, to build the Pipeline.

Here is my Jenkinsfile in https://gitlab.com/carles.mateo/python_combat_guide/-/blob/master/Jenkinsfile

pipeline {
    agent any
    stages {
        stage('Show Environment') {
            steps {
                echo 'Showing the environment'
                sh 'ls -hal'
        stage('Updating from repository') {
            steps {
                echo 'Grabbing from repository'
                withCredentials([usernamePassword(credentialsId: 'ssh-fast', usernameVariable: 'USERNAME', passwordVariable: 'USERPASS')]) {
                    script {
                        sh "sshpass -p '$USERPASS' -v ssh -o StrictHostKeyChecking=no $USERNAME@$ip_fast 'git clone https://gitlab.com/carles.mateo/python_combat_guide.git; cd python_combat_guide; git pull'"
        stage('Build Docker Image') {
            steps {
                echo 'Building Docker Container'
                withCredentials([usernamePassword(credentialsId: 'ssh-fast', usernameVariable: 'USERNAME', passwordVariable: 'USERPASS')]) {
                    script {
                        sh "sshpass -p '$USERPASS' -v ssh -o StrictHostKeyChecking=no $USERNAME@$ip_fast 'cd python_combat_guide; docker build -t python_combat_guide .'"
        stage('Run the Tests') {
            steps {
                echo "Running the tests from the Container"
                withCredentials([usernamePassword(credentialsId: 'ssh-fast', usernameVariable: 'USERNAME', passwordVariable: 'USERPASS')]) {
                    script {
                        sh "sshpass -p '$USERPASS' -v ssh -o StrictHostKeyChecking=no $USERNAME@$ip_fast 'cd python_combat_guide; docker run  python_combat_guide'"

My Jenkins Docker installation has the sshpass command, and I use it to connect via SSH, with username and Password to the server defined by ip_fast environment variable.

We defined the variable ip_fast in Manage Jenkins > Configure System.

There in Global Properties , Environment Variables I defined ip_fast:

In the Build Server I’ll make a new user and allow it to build Docker:

sudo adduser jenkins_build

sudo usermod -aG docker jenkins_build

The Credentials can be managed from Manage Jenkins > Manage Credentials.

You can see how I use all this combined in the Jenkinsfile so I don’t have to store credentials in the CVS and Jenkins (Docker Container) will connect via SSH to make the computer after ip_fast Ip, to build and run another Container. That Container will run with a command to do the Unit Testing. If something goes wrong, that is, if any program return an Exit Code different from 0, Jenkins will consider the build fail.

Take in count that $? only stores the Exit Code of the last program. So be careful if you pass multiple commands in one single line, as this may mask an error.

Separating the execution in multiple Stages helps to save time, as after a failure, execution will not continue.

Also visually is easy to see where the error is.