Forem: Purvesh Shende

Setting Up a Multi-Tier Web Application Locally: A DevOps Guide

Purvesh Shende — Wed, 25 Sep 2024 00:01:52 +0000

For any developer or DevOps engineer, setting up and managing a multi-tier web application can be a daunting task, especially when working locally. But with the right tools, the process can be automated and simplified—saving you time and headaches. Let’s dive into how I automated the setup of a multi-tier web app using Vagrant, Oracle VM VirtualBox, and Git Bash.

Why Local Setup?

When you're in the middle of a project, making changes directly on live servers can be nerve-wracking. What if something breaks? What if it's not easily reversible? The ability to experiment and configure the entire application stack locally can make a world of difference, allowing you to research, experiment, and troubleshoot without any risk to production environments.

But manual setup? It’s often:

Complex — so many services, dependencies, and configurations.
Time-consuming — doing it from scratch every time is tedious.
Not repeatable — making it hard to maintain consistency across multiple environments.

The Solution? Automate it Locally

I used three core tools to automate the setup:

Oracle VM VirtualBox for the hypervisor.
Vagrant to automate the provisioning of virtual machines (VMs).
Git Bash as the command-line interface (CLI).

This setup allows you to automate the process of provisioning and configuring your VMs while integrating multiple services required to run a full web application. Let’s break it down.

Project Architecture: What Are We Building?

Imagine you’re setting up a social networking site written in Java. You need to configure several services across different virtual machines, and these services need to communicate seamlessly. Here’s the stack we’ll be working with:

NGINX — Web server and reverse proxy.
Tomcat — Application server.
RabbitMQ — Message broker.
Memcached — In-memory data caching.
MySQL — Relational database.

Step-by-Step Setup

1. Provisioning the VMs with Vagrant

Start by writing your Vagrantfile. This file contains all the configuration needed to spin up VMs with VirtualBox. Use $ vagrant up to boot your VMs and $ vagrant ssh to access them. Each service will run on its own VM.

Commands like $ vagrant global-status help you check the status of your machines. You can bring them up or down as needed with $ vagrant reload.

2. Setting Up MySQL

Once your MySQL VM is up and running, SSH into it ($ vagrant ssh db01). Start by installing MariaDB. Don’t forget to run the mysql_secure_installation script to secure your database.

From there, you can create databases, configure users, and load your SQL backups.

3. Configuring Memcached

Memcached is great for caching. Once SSH'd into your Memcached VM ($ vagrant ssh memcached), install it and open the appropriate ports for communication. With Memcached, you can speed up your app by reducing the load on MySQL.

4. Setting Up RabbitMQ

RabbitMQ is used to handle messaging and queuing in distributed systems. After SSH'ing into your RabbitMQ VM ($ vagrant ssh rmq01), install RabbitMQ and configure it to start on boot. Don’t forget to enable the necessary ports and configure user roles for messaging.

5. Deploying Tomcat

The Tomcat VM hosts your web application. After installing Tomcat, configure it to auto-start and deploy your web app using Maven. You can also create a script for automatic deployment and link it to a systemd service for even smoother operation.

6. NGINX Configuration

As the entry point to the application, NGINX handles HTTP requests and balances the load. The NGINX VM is configured to route requests to the Tomcat VM, ensuring efficient distribution of traffic.

7. Connecting It All Together

Once the services are up and running, the magic happens. Requests sent to NGINX get forwarded to Tomcat, where the application is processed. Database queries go through Memcached first for faster lookups, while MySQL holds all the actual data. RabbitMQ handles message queuing, and each component communicates seamlessly through properly configured networking and hostnames.

Wrapping Up

At the end of the day, this local setup allows you to create a repeatable and automated environment for experimenting with a multi-tier web application. You’re free to break things, fix things, and tweak the setup as much as you need without worrying about impacting live servers.

And when you’re done? $ vagrant destroy --force will tear it all down, clean as a whistle.

HTML Crash Course

Purvesh Shende — Tue, 23 Feb 2021 18:46:35 +0000

Hey folks🔥 I am here with another blog this time we are going to learn the basics of HTML. This is for the people who are starting with web and want to learn HTML in an easy and structured way.
Whether you’re interested in becoming a professional web developer or you simply want to learn more about how websites work, the first thing you need to study is HTML.
Without wasting more time let's get started.

What is HTML?

HTML is the standard mark-up language for creating Web pages.
HTML stands for Hyper Text Mark-up Language, HTML describe the structure of the page. Consist of series of elements
Html element tell the browser how to display the content.
It allows the user to create and structure sections, paragraphs, heading links and blockquotes for web pages and applications.
Html is not a programming language, meaning it doesn’t have the ability to create dynamic functionality. Instead, it makes it possible to organize and format documents.

Versions of HTML –

The first version of HTML was developed by physicist Tim Berners-Lee in 1990, and the first publicly available version was released in 1991. Since then, HTML has been updated numerous times to address advances in technology.
The current standardized version is HTML5, which has been in use since 2014.

A simple HTML Document structure -

<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
</head>
<body>
  <h1>My First Heading</h1>
  <p>My first paragraph.</p>
</body>
</html>

The <!DOCTYPE html> declaration defines that this document is an HTML5 document.
The <html></html> element is the highest level element that encloses every HTML page.
The <head></head> element holds meta information such as the page’s title and charset.
The <title></title> element specifies a title for the HTML page.
The <body></body> tag encloses all the content that appears on the page.
The <h1> element defines a large heading
The <p> element defines a paragraph

HTML Editors –

1 – Sublime Text
2 – Atom
3 – Visual Studio code
4 – Notepad ++
5 – Brackets

What is an HTML element?

An HTML element is defined by a start tag, some content, and an end tag.
The HTML element is everything from the start tag to the end tag.
Tags are used to mark up the start of an HTML element and they are usually enclosed in angle brackets.
EX : <h1> Hello World !</h1>

Golden Rules for using HTML tags –

You must always use angle brackets for tags.
you must always close a tag after opening it.
When using multiple tags, the tags must be closed in the order in which they were opened.

Ex :
<strong><em> Hello </em></strong>

What are the HTML attributes?

HTML attributes provide additional information about HTML elements.
Attributes are always specified in the start tag.
Example –
The <a> tag defines a hyperlink , the href attributes specifies the URL of the page.
<a href=https://www.google.com> Visit Google </a>

Adding stuff to HTML file –

The <img> tag is used to add an image in an HTML page. Image link goes into a src attribute of img tag.
Headings have 6 levels in HTML. They range from <h1></h1> to <h6></h6>, where h1 is the highest level heading and h6 is the lowest one.
The <b></b> tag specifies bold text without any extra importance.
The <strong></strong> tag is used to define text with strong importance. The content inside is typically in bold.

Now that you’ve gotten started with HTML, you can improve your skills. It’s exciting to see everything to see you can do with web pages check out world’s best tutorial W3-schools

Hope you like it.

Thank you❤️ for reading my blog. Feel free to connect on LinkedIn or Twitter :)

Photo by Goran Ivos on Unsplash

Best Programming Languages in 2021👩‍💻

Purvesh Shende — Sat, 23 Jan 2021 18:15:34 +0000

It’s a new year, a time when many technologists are considering which new skills and programming languages to learn. So here I’m with this blog.

Follow me!⬇️

#1 Python –

Currently the most popular programming language on this planet 🌎 is Python .It was designed for readability, and has some similarities to the English language. Python is an interpreted, high-level ,general-purpose and object-oriented programming language. It is free , open source and python has a huge community support. Python is the most easy language in implementation in AI, Machine learning and data science.

Common uses of python –

Machine Learning and Artificial Intelligence
Internet of things
Data Science and Data Visualization.
Desktop GUI
Web Development
Game Development
Business Applications & many more..

Companies that love ❤️ Python –

Google
Facebook
Instagram
Spotify
Netflix & many more ..

#2 JavaScript –

One of the top and most popular programming language is JavaScript. Java and JavaScript are exactly opposite just like a cat has nothing to do with catfish,JavaScript has nothing to do with java. It doesn’t require compilation and is interpreted with object-oriented capabilities. Also, it works with various other programming languages. And this is the reason for its vast use all around the world.
JavaScript use in developing great backend and frontend webapps as well as Native apps using frameworks like React Native, JavaScript allows users to interact with web pages.

Common uses of JavaScript–

Adding interactive behavior to web pages
Creating web and mobile apps
Building web servers and developing server applications
Game development
Flying Robots & many more..

Companies that love ❤️ JavaScript–

Microsoft
Netflix
PayPal
Google
Uber & Many more

#3 Java –

One of the most popular programming language is Java. It is a class-based, object-oriented programming language and is designed to have as few implementation dependencies as possible. A general-purpose programming language made for developers to write once run anywhere that is compiled Java code can run on all platforms that support Java and that’s the region more than 3 billion devices run Java. Java works on different platforms (Windows, Mac, Linux, Raspberry Pi, etc.) It has a huge community support.

Common uses of Java–

Android Apps
Server Apps at the Financial Services Industry
Java Web applications
Software Tools
Embedded Space
Big Data technologies & Many more ..

Companies that love ❤️ Java–

Google
Intel
Netflix
LinkedIn
Amazon
Phillips & many more..

#4 Kotlin –

whenever there is a talk of android app development – the name of ‘Kotlin’ undoubtedly comes first! Though, a huge inclination of developers towards Kotlin is noticed after Google declared it as its preferred language for Android application development. Kotlin is a statically typed general-purpose programming language that supports object-oriented as well as functional programming feature.

Common uses of Kotlin–

App development
Server side & Client side web development
support for other platforms such as embedded systems, macOS and iOS is coming.

Companies that love ❤️ Kotlin–

Google
Amazon
Netflix
Pinterest
Uber
Foursquare
Trello

#5 c++ –

C ++ one of the most popular programming language in the competitive world as well as development world . C++ is a cross-platform language that can be used to create high-performance applications. C++ was developed by Bjarne Stroustrup, as an extension to the C language. C++ gives programmers a high level of control over system resources and memory.

Common uses of C++ –

Games
GUI Based Applications
Database Software
Operating Systems
Browsers
Banking Applications
Cloud/Distributed System
Embedded Systems & many more..

Companies that love ❤️ C++ –

Apple
Google
Maya
Infosys
Mozilla Firefox & many more ..

#6 Go –

Go also known as Golang is an open source, compiled and statically typed programming language developed by Google Go is a general-purpose programming language with a simple syntax and is backed by a robust standard library. One of the key areas where Go shines is the creation of highly available and scalable web apps ,command-line applications, desktop apps and even mobile applications.

Common uses of Go –

Command line applications
Desktop apps
Mobile apps

Companies that love ❤️ Go –

Google
Uber
Twitch
Dailymotion & Many more ..

#7 Ruby -

A dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write. Ruby is a pure Object-Oriented language developed by Yukihiro Matsumoto in the mid 1990’s in Japan. Ruby has similar syntax to that of many programming languages like C and Java, so it is easy for Java and C programmers to learn. It supports mostly all the platforms like Windows, Mac, Linux. frameworks like Ruby on Rails helps developers to build websites and applications, providing structure for all the code they write.

Common uses of Ruby–

Web development
Text processing
Network programming
General programming
GUI applications
Data analysis & many more..

Companies that love ❤️ Ruby–

GitHub
Apple
Twitter
Airbnb & many more..

#8 C# -

For the last many years, C# is holding a good position in the list of top programming languages of almost every index. It is an object-oriented programming language created by Microsoft that runs on the .NET Framework. C# is close to other popular languages like C++ and Java. It is easy to learn and simple to use. C# has huge community support.

Common uses of C#–

Mobile applications
Desktop applications
Web services
VR
Games & many more..

Companies that love ❤️ C#–

Microsoft
Accenture
Alibaba Travels
Stack Overflow & many more..

Thank you❤️ for reading my blog. Feel free to connect on LinkedIn or Twitter :)

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Git for beginners

Purvesh Shende — Wed, 13 Jan 2021 19:35:00 +0000

Welcome to Git for beginners blog, Hope you are doing well and staying home and staying safe, Here is git cli blog
So ,
what is git -
Git is distributed version control system for tracking changes in source code during Software development . It is designed for coordinating work among programmers ,but it can be used to track changes in any set of file. Its goals include speed, data integrity ,and support for distributed non linear workflows.

How to install Git
Go to the Git Website

Getting started -

What is a git repository

This is a folder inside your project where git tracks all the changes made in the files and build a history reference over time. In your project the git repository folder you will see a .git folder.

Basic Commands –

To create a folder : mkdir Hello
To create a file: touch index.html style.css
To delete a file : rm index.html
To see inside a folder : ls (Ls)/ dir
To move up a folder : cd ..
To delete a folder : rmdir Hello
To go in any folder : cd

To get started with Git, go to your terminal and run the following command in your project directory.

Git config-
To set your user name and email in the main configuration file.

Command –

git config –global user.name “robin”
git config –global user.email “robin@example.com”

Git init –
To initialise a git repository for a new or existing project.
Get into root directory and type following command.

Command –

    git init

Git Clone-
Git clone is a git command line utility which used to target an existing repository and create a clone , or copy of that target repository , also sets the remote to original source so that you can pull again.

Command-

git clone <git url to clone>

Git status-
To check the status of files you’ve changed in your working directory

Command:

git status

Git add-
To add changes to your working directory so that git can index those files.

Command –

git add .

To add all changed files to git or
Just type “git add filename”

Git Commit-
This command is use for to commit changes you have made and sets it to new commit object for your remote

Command –

git commit -m”your message”

Git Pull / Push-
This command is use for push or pull your changes to remote . If you have added and committed your changes and you want to push them and if your remote has updated and you want those latest changes.

Command –

git pull<remote><branch> and 
git push<remote><branch>

Git Branch –
It will list out all of the branches

Command –

git branch

or

git branch -a

to list remote branches as well.

Git checkout –
To switch between different branches.

Command –

git checkout <branch name> or
git checkout -b<branch name>

Git Stash –
To save changes that you don’t want to commit immediately.

Command –

git stash

or

git stash apply

in your working directory.

Git merge–
To merge two branches you are working

Command –

First checkout the branch into which you want to merge other branch and then type

git merge <name_other_branch>

Git logs–
This will list all of the commits you have made into working directory this shows the history of commits with their ids and information.

Command –

git logs

Git Revert–
To revert the changes to last commit.

Command –

git revert<commit-id>

Git Remote–
To check what remote/ source you have or you want to add a new remote

Command –

git remote and git remote add <remote_url>

Thank you for reading my blog. Feel free to connect on LinkedIn or Twitter :)