Getting Started With RabbitMQ in 10 Minutes

RabbitMQ is one of the most popular opensource message broker/Queuing engine available in the market.. It has been used as communication(Message Oriented) bridge in many software architectures.. Communication between Microservices is one of the obvious use case where we can use MQ to make things simple .. RabbitMQ makes communication between services easy with it's simple messaging system.. Rabbit MQ supports multiple protocols like AMQP

In one of our projects, We've used it to delegate the heavy processing things to worker process written in python form single threaded NodeJs process.. thus it makes easy to scale our services and opened the doors to polyglot architecture for our services... we enjoyed it a lot.. So I thought to write a simple article which will help people to get start with RabbitMQ in 10 minutes..

Installing RabbitMQ (In Ubuntu based systems)

First update source-list and add signing key

Now add repository to source list

Now update the source list and install the RabbitMQ ....

The server is started as a daemon by default when the RabbitMQ is installed.

Verify the installation.. with the following command...

And also I'll show you small how to with NodeJS and RabbitMQ.. for this you need to have Node installed in your system.. If you haven't installed NodeJs you can check the instructions here..

First you need to install amqplib.. it's RabbitMQ client for NodeJs..

Then create two files named.. sender.js and receiver.js

Now you can run the receiver.js and and publisher.js and you can see the output like one shown below...

If you want to use it with other languages.. please check official guide.. https://www.rabbitmq.com/getstarted.html

That's it for now.. If you like.. don't forget to share it guys.. You can follow us on fb.com/opensourceinside and also subscribe our channel on Youtube..

How To Install Docker In Ubuntu Linux 14.04, 16.04 And 18.04

I'm going to show you how to install and run Docker in Ubuntu Linux

First update source-list

Install required dependencies..

Then.. Add docker's official GPG key with following command..

The above commands output will looks like..

Now add Docker Community Edition's repository to list..

Now update the package index once again..

Now Install the docker..

The Docker daemon starts automatically.

Verify the installation.. with the following command...

Here is the video version of above tutorial..

That's it for now.. If you like.. don't forget to share it guys.. You can follow us on fb.com/opensourceinside and also subscribe our channel on Youtube..

Installing Multiple Versions Of NodeJs Versions On Your Linux System

Today, I'm going to show you how to install and manage multiple versions of NodeJs on your linux system.

We are going to use NVM to install and manage multiple versions of NodeJs on same system. So we need to install NVM first.. To install it just copy paste the below command.

The above script will download and install NVM on your Linux box.. Now run the below command to activate it in current terminal session or just close and open your current terminal session.

Now just check the NVM installation with following command..

It should print version like one shown below..

Installing NodeJs with NVM

Now we are going to see how to install the latest version of Nodejs using NVM..
Just Run the below command to install latest version of nodejs in your system

This will produce output like one shown below.. on successful installation..

You can check the version of node installed with node -v and npm with npm -v

You can install particular version of NodeJs with npm install version-number. For example to install NodeJs version 8 you can use nvm install 8

To check the different versions of NodeJs installed in your local system.. run the following command

To switch from one version to other you can use following command.. nvm use version number. for example to use Node Version 10 you have to run nvm use 10

If you want to set some node version as default version to use ... you can set it with following command.. nvm alias default node-version.. if you want to set the node version 8 as default one you can set it by running this command nvm alias default 8

Here is the video for above tutorial...

That's it for now.. Thank You.. If you like don't forget to share it guys.. You can follow us on fb.com/opensourceinside and also subscribe our channel on Youtube..

Finding Application / Process Running On Particular Port In Linux Systems

Today, I'm going to show you how to find application / process running on particular port in Linux Systems.

We can use lsof command to find the process running on particular port. The syntax of lsof command to find the application running on particular port looks like following..

Summary of above code...
lsof command is used to list open files.. and the argument -i is used to list files whose ip address / port matched to specified ip address / port.

Note: If you ignore ip address / port after -i then the above command will lists processes for all ip addresses...

For example to find the process / application listening on port 80, run the following code..

The output will looks like following..

If you omit port value... lsof -i the output will looks like following one..

By specifying -t for lsof command we can get pid of process listening on particular port... Look at the below command signature..

If you want to find out pid of process listening on port 80, run the following code..

The above commands output will looks like..

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How To Solve Sublime Text Not Showing In Optional Application List Of Open With Menu On Right Click

I just installed sublime text in my new Linux box.. And tried to open text file with it instead of default editor.. So I clicked on 'Open With' option in Right Click menu.... But I couldn't see sublime-text in application list shown on clicking 'Open With'...

So I just googled for solution... It's easy to fix... We just need to copy desktop entry to local list of desktop entries list...

Just Run The Following Lines.. To Make Things Work...

Step 1 :

Just Copy the contents of /usr/share/applications/sublime_text.desktop to ~/.local/share/applications/sublime_text.desktop

Step 2 :

Now Just update the index of desktop entries... sudo update-desktop-database

That's It Now It will appear at menu list of 'Open With'...

Just check the video... Friends... Don't Forget To Subscribe...

Disabling/Changing Drum Beat Sound On Ubuntu Startup

Ubuntu would always play, Drum Beat sound on Ubuntu system startup, But some people may find this is annoying and want to disable or want to change it with their own custom alert sound... Unfortunately, Ubuntu haven't provided a simpler GUI way to disable/customize the startup sound (so far I know..).

However, it's not that much hard to disable/change the startup sound. In this post I will show you how to change/disable startup sound in Ubuntu.

Mostly, All sounds which generally used by Ubuntu are .ogg format sound files and they are located in /usr/share/sounds/ubuntu/. We can disable or change the startup sounds just by renaming/replacing the corresponding sound file...

Disable Startup Sound :

To disable startup sound we just have to rename the file named system-ready.ogg which is located in /usr/share/sounds/ubuntu/stereo/. Just run the below command to disable the startup drum beat in your Ubuntu system..

Changing The Startup Sound With One You Like To Hear..

We can change/customize our startup sound just by replacing existing system-ready.ogg with our own sound file (should be in .ogg format) with existing name (system-ready.ogg)..

I have already mentioned that Ubuntu use .ogg file format for its alert sounds.. So your new sound file also should be in that format.. Don't worry, If you don't have your sound file in .ogg format.. You can just convert your sound file from current format to .ogg .. There are many tools available to do that for you.. Even you can convert it in online... media.io is one of such kind of web site where you can freely convert your sound file to .ogg format..

Now, if you have your new sound file with .ogg format in your hands.. Then... Just disable existing sound by running following commands..

For Example..

If you have your new file named beep.ogg in your Downloads directory.. Then you have to execute following command....

That's it.. Now just restart your system and see the change... Follow us on facebook.

How To Get Rid Of
"N: Ignoring file '20auto-upgrades.ucf-dist' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension"
Warning Message In Ubuntu 16.04

As usual, today morning, I ran sudo apt-get -y upgrade in my Ubuntu Linux box.. But at the end of the upgrade I got "N: Ignoring file '20auto-upgrades.ucf-dist' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension".... I googled about it to find the reason for this kind of nasty warnings...

Finally, found the reason and solution for this issue from Ask Ubuntu...

According to AskUbuntu, The reason for this warning message is, the update contains a new version of configuration file.. but if you choose system package manager to keep old one itself... then the new config file would just exists there, along with old configuration file...

So every time we use package manager, it is printing file with invalid extension warning message... However, it will not cause any issues.. We can just ignore it... But if you want to get rid of this warning message.. Just follow the bellow instructions...

We can get rid of this message by removing redundant new configuration file which came with updates..
Just execute bellow command to remove the new redundant configuration file.. So that we can get rid of warning message..

Now run sudo apt upgrade... This time you wouldn't get warning message..

Thats all... Follow us on facebook fb.com/opensourceinside..

Installing Rust On Ubuntu 16.04 and 14.04

Rust, also known as Rust-Lang, is a new programming language which aims safety, speed and concurrency... It's designed to create highly concurrent and secure Applications/Systems by having more a number of compile-time safety checks that produce no runtime overhead, while eliminating all data races.... According to documentation, Rust also aims to achieve ‘zero-cost abstractions’ even though some of these abstractions feel like those of a high-level language.

Here.. We are going to see how to install and getting start with rust on Ubuntu Linux 16.04 & 14.04

Step 1: Update Source(Package) List

Open terminal and run the following commands to ensure that package source list is upto date and also install curl...

For Ubuntu 16.04

For Ubuntu 14.04

Step 2: Install Rust

Now run the following command which download and runs a script that will install rust on your Linux box..

Or If you have curl installed..

Rust packages are available in three different release channels namely stable, beta and nightly... The above command will install current stable version of rust on your system..

If you want to install beta version(A preview of the upcoming stable release, intended for testing) of rust, run the following command..

Or

If you want to enjoy features that are not available in stable and beta channels, install rust from nightly release channel.. (Be aware, Features which are available in nightly channel are unstable may change anytime before they get into beta channel)

Or

Step 3: Verify The Installation

You can verify the successful installation of rust in your System by running rustc -V . You will get output similar to output shown below..

Get start with rust..

If you see output similar to above.. that means your installation was successful.. So now here i am going to show how to write a hello world program in rust and run it..

Create file named main.rs, open it with your favorite text-editor, then copy and paste the following code in that file and save it...

Now compile it with rustc main.rs, you will get executable file named main .... execute it by running ./main .. You will see.. "Hello, World" text on your screen..

Here, You Can Learn Rust Programming..

Here is the video for above tutorial...

How To Install And Configure Postfix To Send Mail By Using Gmail As Mail Relay In Ubuntu 16.04 & 14.04

Postfix is a cross platform, free and opensource Mail Transfer Agent (MTA) designed to be an alternative to the widely-used Sendmail program. The main aim of Postfix is to be fast, easy to administer, and secure. The outside has a definite Sendmail-ish flavor, but the inside is completely different. Today we are going to see how to install and configure Postfix to send E-mail using gmail as mail relay server... and I'm using Ubuntu 16.04 LTS for this tutorial..(also tested in 14..04)

Installation

You can get Postfix from offical Ubuntu repositories.. So you can install it by running the apt install command..

For Ubuntu 16.04

For Ubuntu 14.04

Postfix Configuration..

During the installation of Postfix, you will be asked to choose default configuration for postfix...
Select Internet Site...

Enter Fully Qualified Domain Name(FQDN).. for example if you are going to use myuser.example.com then you have to fill example.com for following field..

After installation has completed successfully, proceed following steps to use gmail SMTP server as relayhost.

Configuring Postfix To Use Gmail's SMTP server as Relayhost..

Now we will see how to configure Postfix to send E-mails using gmail as relay host.. To do this we need to edit /etc/postfix/main.cf... open main.cf file in your favorite text editor.. here i am using sublime text(it's my favorite editor ☻)..
See How To Install Sublime Text On Linux

If you want to open with gedit run following the command..

Then add following lines to the end of main.cf file..

And also set relayhost value to [smtp.gmail.com]:587..

Configure Gmail Username and Password For Authentication :

first you have to create file named sasl_passwd inside /etc/postfix/...

Then open recently created file with your choice of text editor..

or, if you have sublime text editor... run following..

Now add your smtp server address, port, username and password details in the format shown below..

For our case (gmail)... following is more suitable example...

You have to Turn On Allow less secure apps in-order to use your Postfix MTA work properly with gmail.. To do this go to https://myaccount.google.com/security/lesssecureapps find Allow less secure apps option and Turn On it..

⇓

then save and create lookup-table or hash for above file.. by running postmap command..
if you ma any changes

Restart or Reload Postfix :

Before you use, You should reload or restart Postfix whenever you make changes to main.cf file..

For Ubuntu 16.04

For Ubuntu 14.04

Or you can reload postfix with it's own implementation..

Testing Postfix Installation

The easy way to test your postfix installation and configuration is use mail command or sendmail command..

Testing using mail command :

You can use mail command to send mail as follows..

For example.. if you want to send mail to [email protected] ... the above command will looks like the following one..

Testing using sendmail command :

You can even postfix's implementation of sendmail command..

Debugging :

If you didn't receive mail, when you test with above commands.. then see mail.log and mail.err files which are present in /var/log/... From these two files you can point-out the problem and it will be helpful for troubleshooting the problem.

Here is the video for above tutorial...

That's it for now.. If you like don't forget to share it guys.. You can follow us on fb.com/opensourceinside and also subscribe our channel on Youtube..

Installing phpMyAdmin in Ubuntu 16.04

phpMyAdmin is an open source tool used for the administration/management of MySQL or MariaDB with the use of a web browser. In addition to offering the capability to perform administration tasks such as creating, editing, or deleting databases, and managing users and permissions, phpMyAdmin provides a graphical user interface to do all of these tasks and more. Here, we are going to see how to install, up and run phpMyAdmin on Ubuntu 16.04.

Install phpMyAdmin

Before you start installing phpmyadmin, install PHP, apache and MySql or similar Db..

Then.. Run following command .. to install phpMyadmin on your Ubuntu installation...

Continue with typing Y once the installation prompts you with Do you want to continue [Y/n]? Like in the image below.

Now we are prompted with dialog selecting our web server, in our case we are selecting apache2 like shown below.

Select <Yes> as we just want a basic installation like shown below.

Now provide a password for phpMyAdmin to use. So that it can register with the MySQL database itself. (Need not to be the same as the MySQL root user)

Enter in the phpMyAdmin password you created in last step to confirm it as follows.

phpMyAdmin is now installed, but, still we have a few more things to do.

Testing phpMyAdmin

Now we will test phpMyAdmin! Open your favorite Web Browser..
and Navigate to http://localhost/phpmyadmin/

If you end up with a page that looks like one shown below... means, phpMyadmin was installed successfully on your system..

Now lets login, the default username for phpMyAdmin is root and the password is what you have entered while installing phpMyadmin... Enter as follows.

Username: root

Password: What you selected earlier

Select Go to login.

When you log in, you'll see the user interface, which will look something like this: