Aug 13

Deploying AKS from Powershell

Azure Kubernetes Services (AKS) allows you to quickly deploy a production ready Kubernetes cluster in Azure. The following are the set of commands which will help you to bring up a K8S cluster in Azure. Pre-requisites Docker service installed azure cli installed git installed Visual Studio Code installed Valid azure account and subscription Agenda Build Image Push images to azure container registry

Aks

1 min read

Aks

1 min read

Deploying AKS from Powershell

Pre-requisites

Docker service installed
azure cli installed
git installed
Visual Studio Code installed
Valid azure account and subscription

Agenda

Build Image
Push images to azure container registry
Create Kubernetes Cluster
Deploy application in Kubernetes
Scale the application
Update the application
Upgrade Kubernetes Cluster
SSH access to VM/AKS Node

Steps

Linux Node AKS Cluster: Link
Windows Node AKS Cluster: Link

Jun 13

How to implement Worker Pool [Thread Pool] in GoLang ?

Worker Pool (Or Thread Pool) is something which enables controlled parallel execution of processes. Parallel execution is by running the tasks under multiple Go-Routines and control is done by limiting the number of Go-Routines. We run a limited number of workers/threads (using a constant defined) always to do processing. It…

Golang

3 min read

Golang

3 min read

May 29

UniversalClient — One client for message brokers and NoSQL DBs

UniversalClient is a one stop client solution for all ( few for now ;) )message brokers and NoSQL DBs. Currently it supports for message brokers like NATS , Kafka and NoSQL Db Redis only. You can find the client in repo : https://github.com/princepereira/Binaries/tree/main/UniversalClientLib Environment $ hostnamectl Operating System: Ubuntu…

Kafka

2 min read

Kafka

2 min read

Mar 6

Implement LRU Cache

LRU or Least Recently Used is the most prominent cache eviction policy used in cache systems. What is the need of Cache ? Microservice or Monolithic based architectures use databases to store information/data. And Databases stores the info in Disks. Accessing (Read/Write) the Disks are resource intensive and time consuming…

Lru Cache

3 min read

Lru Cache

3 min read

Feb 19

Rate Limiter : Token Bucket Algorithm

Implement Rate Limiter using Token Bucket Algorithms Source Code in Golang package main import ( "fmt" "sync" "time" ) func min(a, b int) int { if a < b { return a } return b } type TockenBucket struct { MaxBucketSize int RefillRate…

Rate Limiter

2 min read

Rate Limiter

2 min read

Feb 18

Generating a token in Git

Git supports pushing the files to the repo only through tokens. Here will explain how to generate tokens for Git access. Login to your Github Account 2. Access url: https://github.com/settings/tokens 3. Enter: Generate Token 4. Provide some info in Note 5. Select required checkboxes (I selected all checkbox) 6. Click Generate Token A token will be generated for you. You have to use the generated token to do git clone.

Github

1 min read

Github

1 min read

Generating a token in Git

Git supports pushing the files to the repo only through tokens.

Here will explain how to generate tokens for Git access.

2. Access url: https://github.com/settings/tokens

3. Enter: Generate Token

4. Provide some info in Note

5. Select required checkboxes (I selected all checkbox)

6. Click Generate Token

A token will be generated for you.

You have to use the generated token to do git clone.

How to git clone with generated token

For eg:

Username is : johndoe

Generated Token is : ghp_abc123

Repo is : greetings

Then the git repo url will be :

https://johndoe:ghp_abc123@github.com/johndoe/greetings.git

7. Once the token is generated, you can also set it globally in gitconfig

$ git config --global url."https://${username}:${access_token}@github.com".insteadOf "https://github.com"Eg: git config --global url."https://johndoe:ghp_abc123@github.com".insteadOf "https://github.com"

Feb 8

Make your First Spring Boot Application

Spring boot installation steps Install JDK 11 $ sudo apt install openjdk-11-jdk -y $ java -version Download Gradle $ VERSION=6.5.1 $ wget https://services.gradle.org/distributions/gradle-${VERSION}-bin.zip -P /tmp $ sudo unzip -d /opt/gradle /tmp/gradle-${VERSION}-bin.zip $ sudo ln -s /opt/gradle/gradle-${VERSION} /opt/gradle/latest Setting up environment variables for Gradle $ sudo vi /etc/profile.d/gradle.sh

Spring

1 min read

Spring

1 min read

Make your First Spring Boot Application

Spring boot installation steps

Install JDK 11

$ sudo apt install openjdk-11-jdk -y
$ java -version

Download Gradle

$ VERSION=6.5.1
$ wget https://services.gradle.org/distributions/gradle-${VERSION}-bin.zip -P /tmp
$ sudo unzip -d /opt/gradle /tmp/gradle-${VERSION}-bin.zip
$ sudo ln -s /opt/gradle/gradle-${VERSION} /opt/gradle/latest

Setting up environment variables for Gradle

$ sudo vi /etc/profile.d/gradle.shexport GRADLE_HOME=/opt/gradle/latest
export PATH=${GRADLE_HOME}/bin:${PATH}

Make the script executable and execute

$ sudo chmod +x /etc/profile.d/gradle.sh
$ source /etc/profile.d/gradle.sh
$ gradle -v

Install Spring Boot Cli

$ wget https://repo.spring.io/release/org/springframework/boot/spring-boot-cli/2.6.3/spring-boot-cli-2.6.3-bin.tar.gz 
$ tar -zxvf spring-boot-cli-2.6.3-bin.tar.gz
$ sudo ln -s $PWD/spring-2.6.3/bin/spring /usr/local/bin/spring

Make first Spring Boot Application

$ vi $Projects/Sample/app.groovy@RestController
class ThisWillActuallyRun {@RequestMapping("/")
    String home() {
        "Hello World!"
    }
}

Run the spring boot application

$ spring run app.groovy

Jan 28

HAProxy as a Loadbalancer

HAProxy can be used as Loadbalancer as well as Reverse Proxy. Here will be providing steps to bringup HAProxy as Loadbalancer. Environment Ubuntu 20.04 VM, Docker installed Following are the steps: Bring up multiple web servers Create a docker network sudo docker network create --driver=bridge mynetwork Create Webserver 1 sudo docker…

Haproxy

2 min read

Haproxy

2 min read

Jan 21

Evaluating Postgresql DB with Apache JMeter

We can use Apache Jmeter for Evaluating Postgresql DB Bring up Postgresql in Docker Bringup Postgresql in Docker $ mkdir -p $HOME/docker/volumes/postgres $ docker run --rm --name pg-docker -e POSTGRES_PASSWORD=docker -d -p 5432:5432 -v $HOME/docker/volumes/postgres:/var/lib/postgresql/data postgres Login to Postgres Docker $ sudo docker exec -it pg-docker bash Configure Postgresql DB …

Postgresql

2 min read

Postgresql

2 min read

Jan 21

Tree Operations in Golang

Tree operations [Insertion, Inorder, Postorder, Level order] Explained package main import ( "fmt" ) type Node struct { Val int Left *Node Right *Node } func NewNode(val int) *Node { node := &Node{Val: val} return node } func AddNode(head *Node, val int) *Node { if head == nil {…

Golang

1 min read

Golang

1 min read