Entries by Nikolas

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Cartooning A Webcam Stream With Python’s OpenCV

  import cv2 # Create a VideoCapture object and read from input file # If the input is the camera, pass 0 instead of the video file name webcam = cv2.VideoCapture(0) # Check if camera opened successfully if (webcam.isOpened()== False): print("Error opening video stream or file") # Read the video while(webcam.isOpened()): # Capture frame-by-frame ret, […]

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How To Install PortWorx On A Kubernetes Cluster

Introduction Portworx is a software-defined persistent storage solution designed and purpose-built for applications deployed as containers, via container orchestrators such as Kubernetes, Nomad, Marathon,  and Docker Swarm. In this tutorial, you will learn how to install Portworx on a Kubernetes Cluster consisting of 3 nodes.  It is a clustered block storage solution providing a Cloud-Native […]

Linux Administration Commands Cheat Sheet

System Administration System Information uname -a uname -r IP Address Management ifconfig eth0 #show specific interface On Centos ifconfig ens3 #show specific interface On Ubuntu ip addr show ens3 #show specific interface hostname -I|cut -d" " -f 1 #current ip of system/node hostname -I | awk {'print $1'} Disk Information Display All FileSystems df -ah […]

Fizzbuzz Challenge In Javascript, Bash, Python, and PhP

Introduction The “Fizz-Buzz programming test” is an interview technical question aiming to filter out the 99.5% of programming job candidates who can’t seem to program their way out of a wet paper bag. The text of the programming assignment is as follows: Given a number n, for each integer i in the range from 1 […]

Git Commands Cheat Sheet

Git Basics Creating a new repository mkdir project cd project git init git remote add origin git@github.com:yourlogin/your-repo.git git add . git commit -am “new repository” git push -u origin master Git Clone Clone repo located at<repo>onto the local machine. The original repo can be located on the local filesystem or on a remote machine via […]

How To Create A CI/CD Pipeline With Jenkins

Introduction In a previous tutorial, you learned how to install Jenkins on a Kubernetes Cluster.  In this tutorial, we will create a Jenkins CI/CD pipeline to build a docker image, test it on a staging server to make sure it works as expected, and then push it to Docker Hub. Prerequisites Jenkins installed on a […]

Automatic Scaling Jenkins Pods on Kubernetes

Introduction Jenkins is one of the most popular CI/CD tools for many companies nowadays, but it doesn’t scale out of the box. One could simply add more nodes and connect them with the Master Jenkins node, but that would consume extra infrastructure resources with all the negatives that come with it. In this tutorial, you […]

How To Install Jenkins On A Kubernetes Cluster

Introduction Jenkins is a CI tool ( continuous integration) that automates a large portion of the software development process. Several development teams working on multiple projects in a complex microservices environment can be a strain on limited resources.  In this tutorial, you will learn how to install Jenkins and create a CI/CD pipeline. Prerequisites Docker installed on […]

Kubernetes Automated Bash Install Script

Following up on the tutorial about installing Kubernetes and Flannel on Ubuntu, might be useful for some people to automatically install K8s via a bash script. The code below will take care of that. It includes removal of existing Docker and Kubernetes installation (if any), and install fresh copies while updating the hostname, configures Docker […]