Cloudflare err_ssl_protocol_error - Fix it Now ?

This article covers methods to resolve Cloudflare ERR_SSL_PROTOCOL_ERROR. Basically, this error happens as a result of a number of reasons that include wrong DNS settings, SSL mode, TLS version or issues with SSL certificate. 


To fix this error,

1. If you are not the site owner, contact the site owner and let them know you are having issues accessing their site.

2. The domain name has not fully been set to use Cloudflare yet. Check to see if there are non-Cloudflare nameservers that are conflicting with the assigned Cloudflare name servers.

3. You are signed up for Cloudflare, but you have set a DNS record to :grey:. If you have a subdomain or hostname and that serves HTTP/HTTPS traffic, we would advise that you :orange: this DNS record to take advantage of Cloudflare’s security and performance features. See What subdomains are appropriate for :orange:/:grey: clouds? 69

4. The Free Universal SSL certificate hasn’t yet been deployed, :grey: (deactivate) Cloudflare so that your website can continue to use your origin’s SSL certificate. Wait 24 hours and :orange: (activate) Cloudflare again to see if your SSL certificate has been successfully deployed.

5. You have some conflict with TLS 1.3, disable it and see if you still encounter the error.

6. You have selected Full SSL (strict) under your SSL/TLS app, but your origin does not have a valid certificate (i.e., it is expired, self-signed, or not issued by a trusted CA). Temporarily select another SSL option until you have a valid origin certificate in place.

7. Try to look at developer web console (firefox Ctrl+Shift+K) - anything interesting under Security tab.

8. Also, Try to run the command curl -vk on the affected domain.

Configure Varnish with Apache - How to do it

This article covers how to configure Varnish #cache on the #Apache server. Varnish is an HTTP accelerator and a useful tool for speeding up a server, especially during a times when there is high traffic to a site. 

It works by redirecting visitors to static pages whenever possible and only drawing on the virtual private server itself if there is a need for an active process.

#Varnish is a caching HTTP reverse proxy. It receives requests from clients and tries to answer them from the cache.


Where is varnish configuration file?

The Varnish configuration file will be located in the /etc/varnish directory in CentOS 7. 

To make Varnish work in front of Apache, you will need to set up some basic configurations. 

By default Varnish listens on port 6081 . 

You will need to change port 6081 to 80 so that website requests access the Varnish cache first.


What is varnish WordPress?

Varnish is a full-page cache and HTTP preprocessor which can be used to speed up requests for a WordPress site. 

Setting up Varnish is a technical task, as it requires installing and configuring a system package on a web server, rather than just installing a plugin.

Install OpenCV on Ubuntu

This article will guide you on different methods to install OpenCV on #Ubuntu 20.04. Even though installing the packaged version from the Ubuntu repository is easier, building OpenCV from source gives you more flexibility, and it should be your first option when installing OpenCV.

#OpenCV is the huge open-source library for the computer vision, machine learning, and image processing and now it plays a major role in real-time operation which is very important in today's systems. 

By using it, one can process images and videos to identify objects, faces, or even handwriting of a human.


To install the latest OpenCV version from the source:

1. Install the required dependencies:

sudo apt install build-essential cmake git pkg-config libgtk-3-dev \
    libavcodec-dev libavformat-dev libswscale-dev libv4l-dev \
    libxvidcore-dev libx264-dev libjpeg-dev libpng-dev libtiff-dev \
    gfortran openexr libatlas-base-dev python3-dev python3-numpy \
    libtbb2 libtbb-dev libdc1394-22-dev

2. Clone the OpenCV’s and OpenCV contrib repositories:

mkdir ~/opencv_build && cd ~/opencv_build
git clone https://github.com/opencv/opencv.git
git clone https://github.com/opencv/opencv_contrib.git

3. Once the download is complete, create a temporary build directory, and switch to it:

cd ~/opencv_build/opencv
mkdir build && cd build

4. Set up the OpenCV build with CMake:

cmake -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=/usr/local \
    -D INSTALL_C_EXAMPLES=ON \
    -D INSTALL_PYTHON_EXAMPLES=ON \
    -D OPENCV_GENERATE_PKGCONFIG=ON \
    -D OPENCV_EXTRA_MODULES_PATH=~/opencv_build/opencv_contrib/modules \
    -D BUILD_EXAMPLES=ON ..

5. Start the compilation process:

make -j8

6. Install OpenCV with:

sudo make install


To uninstall OpenCV Linux: 

i. If you installed OpenCV from package manager, it's best to remove those packages. Check: apt list --installed | grep opencv

ii. If you built it yourself, and you still got the build folder, run sudo make uninstall from the OpenCV build directory.

Install XRDP Server

This article will guide you on steps to install XRDP #Server on #Ubuntu. To provide remote access via RDP, a Windows native protocol, XRDP behind the scenes uses #VNC, a remote access protocol more common in Linux.

After #xrdp is installed you can start the server with the following command:

Service xrdp start.

Service xrdp-sesman start (Thanks to Greg for pointing that out) — UPDATE!!

If want it to auto start after reboot you need to run this command also: update-rc.d xrdp enable (It will not start xrdp-sesman automatic).


To use XRDP Linux:

1. With #Ubuntu 18.04 first install xrdp: sudo apt-get -y install xrdp.

2. Next, one may adjust the configuration file: sudo nano /etc/xrdp/xrdp.ini.

3. Set encryption level to high: encrypt_level=high.

4. Next, allow just RDP through the local firewall: sudo ufw allow 3389/tcp.

Microsoft SQL server error 18470 How to fix it

This article will guide you on the different factors that causes SQL server error: 18470 and also how to fix this #error.

In SQL Server Configuration Manager, in the left pane, click SQL Server Services. In the results pane, right-click SQL Server (#MSSQLServer) or a named instance, and then click Start, Stop, Pause, Resume, or Restart.

User gets the #Microsoft SQL Server Error: 18470. This may happen if the SA (System Administrator) user account is disabled in #SQL Server. It can be verified by trying to log in to SQL Server Management Studio (#SSMS) using the SA account. In the Login Properties screen, select Status on the left side.

To Microsoft SQL Server Error 18456:

1. Log In with Remote Desktop.

2. Run Microsoft SQL Server Management.

3. Checking the Server Authentication Mode.

4. Restart the SQL Service.

5. Checking SQL User Permissions.

6. Mapping the User to the #Database.

MySQL BLOB Data Type

This article will guide you on how #MySQL #BLOB data type works in storing and displaying images with #PHP on Ubuntu 18.04. A BLOB is a binary large object that can hold a variable amount of data.
A Binary Large OBject (BLOB) is a collection of #binary data stored as a single entity in a database management system. Blobs are typically images, audio or other multimedia objects, though sometimes binary executable code is stored as a blob.
The four BLOB types are #TINYBLOB , #BLOB , #MEDIUMBLOB , and #LONGBLOB . These differ only in the maximum length of the values they can hold. The four TEXT types are TINYTEXT , TEXT , MEDIUMTEXT , and LONGTEXT .
The size of blob in MySQL:
TINYBLOB - Up to 255 bytes - 1 byte
BLOB - Up to 64 Kb - 2 bytes
MEDIUMBLOB - Up to 16 Mb - 3 bytes
LONGBLOB - Up to 4 Gb - 1 Bytes

List installed software Linux

This article will guide you on different methods to #list all #software, the number of #packages available on the server along with the method to copy them and use them when we reinstall our operating system(#OS).
Yum automatically refreshes the list of packages, whilst with apt-get you must execute a command 'apt-get update' to get the fresh packages.
To list of installed programs in #Linux:
1. Aptitude-based distributions (#Ubuntu, #Debian, etc): dpkg -l.
2. RPM-based distributions (#Fedora, #RHEL, etc): rpm -qa.
3. pkg*-based distributions (#OpenBSD, #FreeBSD, etc): pkg_info.
4. Portage-based distributions (#Gentoo, etc): equery list or eix -I.
5. pacman-based distributions (Arch Linux, etc): pacman -Q.

How To Install MariaDB on Ubuntu Focal Fossa

This article will guide you on steps to install #MariaDB from the #Ubuntu #repositories and from the official MariaDB repositories. You can install MariaDB in two different ways.

To install MariaDB on Ubuntu, follow these steps:

1. Update #packages index. sudo apt update.

2. Once the packages list is updated, install MariaDB by issuing the following command: sudo apt install mariadb-server.

3. The MariaDB service will start automatically.

The default data directory for the MariaDB database server is /var/lib/mysql. The configuration file of MariaDB database server is /etc/mysql/mariadb. conf. d/50-server.

Update Ubuntu from 16 04 to 18 04 via command line

This article will guide you on steps to #upgrade #Ubuntu #version.

To update Ubuntu using #terminal:

1. Open the terminal application.

2. For remote server use the ssh command to login (e.g. ssh user@server-name )

3. Fetch update software list by running #sudo apt-get update command.

4. Update Ubuntu #software by running sudo apt-get upgrade command.

5. Reboot the Ubuntu box if required by running sudo reboot.

Deploy Laravel using Nginx on Ubuntu

This guide will help to set up Laravel with #Nginx on #Ubuntu 16.04. Laravel is the most popular, free, and open-source #PHP #framework in the world, known for its expressive and elegant syntax.
To move laravel project from localhost to production server, do:
1. Zip your #laravel app files.
2. Export your app's #database then set it up on your server.
3. After you have uploaded your laravel app files, open the . env file found on the root.
4. That's it!, now check your live #site.

JupyterLab Environment on Ubuntu 18 04

This article will guide you on the process to set up a JupyterLab Environment on Ubuntu and made it accessible remotely. 

The JupyterLab Credential Store uses a password that you set upon first use. Each credential is encrypted with a hash of your password. The encrypted credentials are stored in the credentialstore file in the #directory you start #JupyterLab from.

You can also create new #environments from within Jupyter Notebook (home screen, Conda tab, and then click the plus sign). And you can create a notebook in any environment you want. Select the "Files" tab on the home screen and click the "New" dropdown menu, and in that menu select a Python environment from the list.

Method to Install Software From Source on Ubuntu

This article will guide you on steps to #install #software from #source on #Ubuntu. The Complete #command is apt-get which is the easiest way to install files/Softwares #packages.

Once installed, on the command line, you can use dpkg --listfiles packagename . For instance, dpkg --listfiles firefox . 

If you want to see what files a package contains without installing it, then you can install apt-file and use that.

Install and Secure phpMyAdmin on Ubuntu

This article will guide you on the process to #install #PhpMyAdmin on Ubuntu. PHPMyAdmin allows users to interact with #MySQL through a web interface and makes MySQL #database #management easier.

SQL error 17806 Steps to fix

This article will guide you on the steps to fix #SQL error #17806 which happen due to Active Directory configuration issue or #Network issues.

Install and Configure ModSecurity on Ubuntu

This article will guide you on the steps to perform #ModSecurity installation on #Ubuntu which involves enabling Core Rule Set to handle malicious activities.

SQL server error 17 Steps to fix it

This article will guide you on the steps to fix 'SQL Server does not exist or access denied' error which occurs when the computer running #Microsoft #SQL Server is not reachable.

cURL 18 transfer closed with outstanding read data remaining

This article will guide you on the steps to fix cURL error 'cURL 18 transfer closed with outstanding read data remaining' which occurs while retrieving data from a #URL using a #cURL.

This #error can be fixed by correcting the permission of #directory '/var/cache/nginx'

SQL error 15123

This article will guide you on the steps to troubleshoot and fix #SQL server #error #15123 which occurs in the process of changing or viewing the values of any advanced server configuration option.

Windows update error 0x80070013

This article will guide you on the different methods to fix this Windows error which affects Windows Update processes.

Fix SQL server error 18

When there is an issue with TLS version or encryption of an SQL server, an SQL server error 18 occurs.

Method to fix Cloudflare error 527

When a #connection is interrupted between Cloudflare data center and an origin #Railgun server(rg-listener), thus a #Cloudflare error 527 will occur. This is influenced by loss of #packet data or a #firewall restriction in this situation.

Fix Cloudflare error 1018

Cloudflare error 1018 is a common Cloudflare error which affects a domain whose DNS is hosted on the Cloudflare network in the case when cloudflare cannot resolve to the domain when trying to access it on a browser.


To resolve Cloudflare error 1016:

1. Verify your Cloudflare DNS settings include an A record that points to a valid IP address that resolves via a DNS lookup tool.

2. For a CNAME record pointing to a different domain, ensure that the target domain resolves via a DNS lookup tool.


Generally, to fix Cloudflare errors:

1. Contact your site administrator or hosting provider to eliminate these common causes.

2. Ensure your origin web server is responsive.

3. Review origin web server error logs to identify web server application crashes or outages.

4. Confirm Cloudflare IP addresses are not blocked or rate limited.

Upgrade from Ubuntu 20.04 to Ubuntu 22.04 - Step by step guide ?

This article covers how to successfully upgrade from Ubuntu 20.04 Focal Fossa to Ubuntu 22.04 Jammy Jellyfish. In fact, Ubuntu 22.04 LTS Jammy Jellyfish is due to release on April 21, 2022. However, users of Ubuntu 20.04 and Ubuntu 21.10 are able to upgrade to the latest release right now.

Upgrade Ubuntu 20.04 to Ubuntu 20.10 - Step by step guide ?

This article covers the process of upgrading Ubuntu from version 20.10 (Focal Fossa to Groovy Gorilla) system. In fact, Being able to upgrade Ubuntu from one version to the next is one of Ubuntu's best features. You benefit from getting the latest software, including new security patches, and all the upgraded technology that comes with a new release without having to resort to reinstalling and reconfiguring your system.

Install Elasticsearch on Ubuntu 20.04 - Best Method ?

This article covers how to install elasticsearch in the stable version of Ubuntu 20.04. Now you can use the hosted elasticsearch server for doing searches.

If your application generates a huge amount of data and the search procedures are slow, then using elasticsearch will be best.

Install Gradle on Ubuntu 20.04 - Best Method ?

This article covers the installation of Gradle on the Ubuntu system using different ways. Gradle is a free and open-source build tool primarily used for Java projects. Gradle helps you to automate, build and deliver software efficiently. Gradle uses Groovy object-oriented programming language instead of XML to define the project configurations. Gradle also supports many popular IDE platforms, such as Android Studio, Eclipse, IDEA, and NetBeans.


How to Install Java on Linux ?

Gradle needs Java to be installed on your system. You can install the latest version of Java by running the following command:

$ apt-get install default-jdk -y 

After installing Java, you can verify the Java with the following command:

$ java -version

Install Arduino IDE on CentOS 8 - Step by Step Process ?

This article covers how to install Arduino IDE on CentOS machine either via the direct download method or the snap method. Also, you will learn how to uninstall Arduino. Arduino IDE stands for the "Arduino Integrated Development Environment". Arduino is used to create electronic devices that communicate with their environment using actuators and sensors. Arduino IDE contains an editor that is used for writing and uploading programs to the Arduino board. Before starting to create projects through Arduino, the user needs to set up an IDE for the programmable board.


How to Launch Arduino IDE on CentOS Linux System ?

Now, you will launch the Arduino IDE from the desktop. Click on 'Activities' and select show application form where you will launch Ardunio IDE to double click on the application icon.

You can also launch using the search bar, click on the 'Activities' where you can see a search bar. You will type 'Arduino' in the search bar.

Install phpMyAdmin with Nginx on Ubuntu 18.04 - Step by Step Process ?

This article covers how to Install phpMyAdmin with Nginx on Ubuntu 18.04 system. When developing a website or web application, many users need the functionality of a database system like MySQL. However, interacting with the system solely from the MySQL command-line client requires familiarity with Structured Query Language — more commonly referred to as SQL — which can present a major hurdle for some users. phpMyAdmin was created to allow users to interact with MySQL through an intuitive web interface, running alongside a PHP development environment. 


How to Secure phpMyAdmin with Let's Encrypt SSL ?

Before starting, you will need to install the Certbot client to download and install Let's Encrypt SSL.

1. First, add the Certbot repository with the following command:

$ add-apt-repository ppa:ahasenack/certbot-tlssni01-1875471

2. Next, update the repository and install the Certbot client using the following command:

$ apt-get update -y
$ apt-get install certbot python3-certbot-nginx -y

3. Once the Certbot has been installed, run the following command to download and install the Let's Encrypt SSL for your domain:

$ certbot --nginx -d phpmyadmin.domain.com

Enable and Disable Root User Account on Ubuntu 20.04 - Do it Now ?

This article covers how to enable and disable root user account in Ubuntu system. Considered the most privileged account on a Unix system, root can perform any tasks needed for system administration.

Navigating a specific folder, killing any process or deleting a directory, root is so powerful that it has to be managed properly.


In order to change the root password, you have to use the "passwd" and specify the root account:

$ sudo passwd root

After changing your password, the account will be automatically unlocked.

In order to switch to the root account, you can use the well-known "su" command without any arguments (the default account is root):

$ su - 


To restart your SSH server for the modifications to be taken into account:

$ sudo systemctl restart sshd

Install Java on Ubuntu 20.04 LTS - Step by Step Process ?

This article covers how to install Java Run-time Environment (JRE) and the Java Developer Kit (JDK) on Ubuntu 20.04. Java is one of the most popular programming languages. It is used for developing anything from lightweight mobile to desktop applications.

Oracle's licensing agreement for Java doesn’t allow automatic installation through package managers. To install the Oracle JDK, which is the official version distributed by Oracle, you must create an Oracle account and manually download the JDK to add a new package repository for the version you'd like to use. 


To install the Default JRE/JDK 

1. To install this version, first update the package index:

$ sudo apt update

2. Next, check if Java is already installed:

$ java -version

If Java is not currently installed, you’ll see the following output:

Output
Command 'java' not found, but can be installed with:
apt install default-jre
apt install openjdk-11-jre-headless
apt install openjdk-8-jre-headless

3. Execute the following command to install the default Java Runtime Environment (JRE), which will install the JRE from OpenJDK 11:

$ sudo apt install default-jre

The JRE will allow you to run almost all Java software.

4. Verify the installation with:

java -version

Install the Let's Encrypt Certificate Using Certbot in Ubuntu 20.04 - How to do it on Nginx web server ?

This article covers how to install Certbot, to get let's encrypt certificates. SSL/TLS encryption is an integral part of the network infrastructure. Any web and mail server allows you to enable data encryption.

To begin, you must have a domain name. Its DNS A-record must contain the public address of your server. If the firewall is enabled, open access for HTTP and HTTPS traffic:

$ sudo ufw allow 80
$ sudo ufw allow 443


To Install the "Let's Encrypt" package on Ubuntu:

1. Run the command below to install Let's Encrypt.

$ sudo apt install letsencrypt

2. Check the "certbot.timer" utility for automatic certificate renewal.

$ sudo systemctl status certbot.timer

Secure Nginx with Let's Encrypt on Ubuntu 18.04 - How to do it ?

This article covers how to install certbot client, obtain Let's Encrypt SSL certificate and configured to Nginx to use the certificates. Also, you will learn how to set up a cronjob for automatic certificate renewal.

Let's Encrypt is a Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers. 


To Install Certbot on Ubuntu:

1. First, add the repository.

$ sudo add-apt-repository ppa:certbot/certbot

You'll need to press ENTER to accept.

2. Install Certbot's Nginx package with apt:

$ sudo apt install python-certbot-nginx

Configure Nginx Server Blocks on Ubuntu 18.04

This article covers how to create an Nginx server blocks to host multiple website on a single Ubuntu machine. When using the Nginx web server, server blocks (similar to the virtual hosts in Apache) can be used to encapsulate configuration details and host more than one domain off of a single server.

Install phpMyAdmin with Apache on Ubuntu 18.04 - Step by Step Process ?

This article covers how to install phpMyAdmin with Apache on Ubuntu 18.04 system. While many users need the functionality of a database management system like MySQL, they may not feel comfortable interacting with the system solely from the MySQL prompt. phpMyAdmin was created so that users can interact with MySQL through a web interface. 


Important php packages includes:

  • php-mbstring: A module for managing non-ASCII strings and convert strings to different encodings.
  • php-zip: This extension supports uploading .zip files to phpMyAdmin.
  • php-gd: Enables support for the GD Graphics Library.
  • php-json: Provides PHP with support for JSON serialization.
  • php-curl: Allows PHP to interact with different kinds of servers using different protocols.

Secure Apache with Let's Encrypt on Ubuntu 18.04 - How to do about it ?

This article covers how to install Let’s Encrypt SSL on Ubuntu 18.04 by using Certbot. Enabling an encrypted connection to the web server is fundamental because it allows you to use the secure HTTPS protocol for your website. Let's Encrypt, a Certification Authority issues a free certificate completely in line with the required security standards. Let's Encrypt simplifies the process for installing the security certificate to help even the less experienced user secure a website through the use of the Certbot client.


To Install Certbot client on Ubuntu:

1. First, add the Certbot repository:

$ sudo add-apt-repository ppa:certbot/certbot

You'll need to press ENTER to accept.

2. Install Certbot's Apache package with apt:

$ sudo apt install python-certbot-apache

Configure Apache Virtual Hosts on Ubuntu 18.04 - Step by Step Process ?

This article covers how to create apache virtual host files to host multiple domains on a single Ubuntu server. Each website published on the Internet is hosted on a web server (host), connected to the network with a public IP address and able to manage requests for web pages on a browser (client) such as Chrome, Firefox or Internet Explorer.

If you need to host a website on your machine, first, install a web server. Among those available, one of the best known is Apache, an open source software compatible with both Unix and Windows systems. 


How to Install Apache on Ubuntu ?

1. To install Apache 2 through the official Ubuntu repositories, proceed by typing:

$ sudo apt-get update
$ sudo apt install apache2

Since Apache communicates externally, it should be inserted among the exceptions of your Firewall. 

2. In case of using UFW, allow bidirectional communications between Apache and a Client by typing:

$ sudo ufw allow 'Apache Full'

3. Apache should already be running. To check its stateuse the command:

$ sudo systemctl status apache2

Install MariaDB on Ubuntu 18.04 - Step by Step Process ?

This article covers how to install MariaDB on Ubuntu 18.04 server. Also, you will learn how to secure and connect to MariaDB server. MariaDB is an open-source relational database management system, commonly used as an alternative for MySQL as the database portion of the popular LAMP (Linux, Apache, MySQL, PHP/Python/Perl) stack. Basically, It is intended to be a drop-in replacement for MySQL.


How to Install MariaDB ?

1. To install it, update the package index on your server with apt:

$ sudo apt update

2, Then install the package:

$ sudo apt install mariadb-server

Install Apache on Ubuntu 18.04 - Step by Step Process ?

This article covers how to successfully install Apache on your Ubuntu 18.04 server. The Apache HTTP server is the most widely-used web server in the world. It provides many powerful features, including dynamically loadable modules, robust media support, and extensive integration with other popular software.


To install Apache on Ubuntu:

1. Update your local package index:

$ sudo apt update

2. Install the apache2 package:

$ sudo apt install apache2

Install LEMP Stack on Ubuntu 18.04 - Step by Step Process ?

This article covers how to Install a LEMP Stack on Ubuntu 20.04 LTS. LEMP stack is a group of open-source software that is typically installed together to enable a server to host dynamic websites and web apps. LEMP stands for Linux OS, with the Nginx (pronounced like "Engine-X") web server, Data store in a MySQL database, and dynamic content is processed by PHP.


To install Nginx Web Server:

1.  Run the commands below to install Nginx.

$ sudo apt update
$ sudo apt install nginx

2. Allow traffic on port 80.

$ sudo ufw allow 'Nginx HTTP'

You can verify the change by running:

$ sudo ufw status

Install LAMP Stack on Ubuntu 18.04 - Step by Step Process ?

This article covers step by step process to install a LAMP stack on an Ubuntu 18.04 server. LAMP stack is a group of open-source software that is typically installed together to host dynamic websites. LAMP stands for Linux OS, with Apache web server, Data store in a MySQL database, and dynamic content is processed by PHP.


To Install Apache and Update the Firewall.

1. Install Apache using Ubuntu’s package manager, apt:

$ sudo apt update
$ sudo apt install apache2

2. Allow incoming HTTP and HTTPS traffic for this profile:

$ sudo ufw allow in "Apache Full"

Configure Static IP Addresses on Ubuntu 18.04 Server - Step by Step Process ?

This article covers method to set up a static IP address on Ubuntu 20.04. Basically, in most network configurations, the IP address is assigned dynamically by the router DHCP server. 

The recommended way to assign a static IP address to a device on your LAN is to configure a Static DHCP on your router. Static DHCP or DHCP reservation is a feature found on most routers which makes the DHCP server to automatically assign the same IP address to a specific network device, each time the device requests an address from the DHCP server. This works by assigning a static IP to the device's unique MAC address.


To Get the name of network interface and the default gateway in Linux:

You can either use ip command or the network manager CLI like this:

$ nmcli d

Install MySQL on Ubuntu 18.04 - Step by Step Process ?

This article covers how to install MySQL version 8.0 on an Ubuntu 20.04 server. By completing it, you will have a working relational database that you can use to build your next website or application.

MySQL is an open-source database management system, commonly installed as part of the popular LAMP (Linux, Apache, MySQL, PHP/Python/Perl) stack. It implements the relational model and uses Structured Query Language (better known as SQL) to manage its data.


To install MySQL using the APT package repository:

1. Update the package index on your server if you've not done so recently:

$ sudo apt update

2. Then install the mysql-server package:

$ sudo apt install mysql-server

This will install MySQL, but will not prompt you to set a password or make any other configuration changes. 

Because this leaves your installation of MySQL insecure, we will address this next.

Download Ubuntu 18.04 LTS ISO File – Desktop & Server

This article covers a review about Ubuntu 18.04 LTS (Bionic Beaver). You can find the Ubuntu 18.04 release notes on its official website.


Ubuntu 18.04.4 (Bionic Beaver) was released on February 12, 2020, the long-term support (LTS) release of the Ubuntu, this was the 4rd point release of the 18.04 LTS and it was available for desktop / laptop computers and servers. Ubuntu 18.04.4 desktop didn't support 32-bit CPU architecture, and is only available to install 64-bit (x86-64) versions. Compared to previous releases, this Ubuntu version includes security updates and fixed bugs.

Add Swap Space on Ubuntu 20.04 - Step by Step Process ?

This article covers how we can add and maintain swap space in the ubuntu system. Swap space can take the form of either a dedicated swap partition or a swap file. Typically, when running Ubuntu on a virtual machine, a swap partition is not present, and the only option is to create a swap file.


To Adjust the Swappiness Value:

Swappiness is a Linux kernel property that defines how often the system will use the swap space. It can have a value between 0 and 100. A low value will make the kernel to try to avoid swapping whenever possible, while a higher value will make the kernel to use the swap space more aggressively.

On Ubuntu, the default swappiness value is set to 60. You can check the current value by typing the following command:

$ cat /proc/sys/vm/swappiness


To Remove a Swap File:

1. First, deactivate the swap space:

$ sudo swapoff -v /swapfile

2. Next, remove the swap file entry /swapfile swap swap defaults 0 0 from the /etc/fstab file.

3. Finally, remove the actual swapfile file using the rm command:

$ sudo rm /swapfile

Configure Network in Linux Using Netplan and NMTUI - Step by Step Process ?

This article covers how to set up your network interface using Netplan and NMTUI. Setting up the network interfaces is one of the most basic step that every system administrator and server engineers have to do to make it accessible over the network.

Netplan is based on YAML based configuration system that makes configuration process very simple. Netplan has replaced the old configuration file /etc/network/interfaces that we previously used for configuring network interfaces in Ubuntu.


To Restart the network service

1. Once all the configurations are successfully applied, restart the Network-Manager service by running the following command:

$ sudo systemctl restart network-manager

2. If you are using a Ubuntu Server, instead use the following command:

$sudo systemctl restart system-networkd


To Verify IP address

Now to verify if the new configurations are successfully applied, run the following command to verify the IP address:

$ ip a


The Netplan default configuration file is under the directory /etc/netplan

You can find that using the following command:

$ ls /etc/netplan/

To view the content of Netplan network configuration file, run the following command:

$ cat /etc/netplan/*.yaml

Install Visual Studio Code on Ubuntu 20.04 - Step by Step Process ?

This article covers how to easily install Visual Studio code on your Ubuntu 20.04 system. Visual Studio Code is an open-source cross-platform code editor developed by Microsoft.

It has a built-in debugging support, embedded Git control, syntax highlighting, code completion, integrated terminal, code refactoring and snippets.


To Install Visual Studio Code on Ubuntu:

1. First, update the packages index and install the dependencies by typing:

$ sudo apt update
$ sudo apt install software-properties-common apt-transport-https wget

2. Next, import the Microsoft GPG key using the following wget command :

$ wget -q https://packages.microsoft.com/keys/microsoft.asc -O- | sudo apt-key add -

And enable the Visual Studio Code repository by typing:

$ sudo add-apt-repository "deb [arch=amd64] https://packages.microsoft.com/repos/vscode stable main"

3. Once the apt repository is enabled , install the latest version of Visual Studio Code with:

$ sudo apt update
$ sudo apt install code

Ubuntu 18.04 LTS (Bionic Beaver) Release

This article covers an overview about Ubuntu 18.04 LTS (Bionic Beaver). Also we covered in details the main features of this Ubuntu release.

The Ubuntu operating system's latest Long Term Support (LTS) release, Ubuntu 18.04 (Bionic Beaver), was released on April 26, 2018. 


To upgrade an Ubuntu system of version 16.04 or later to Ubuntu 18.04:

1. Back Up Your System.

2. Update Currently Installed Packages

Begin by updating the package list:

$ sudo apt-get update

3. Next, upgrade installed packages to their latest available versions:

$ sudo apt-get upgrade

4. Now, use the dist-upgrade command with apt-get, which will perform any additional upgrades that involve changing dependencies, adding or removing new packages as necessary.

$ sudo apt-get dist-upgrade

Upgrade Ubuntu 16.04 to Ubuntu 18.04 LTS - Step by Step Process ?

This article covers method to Upgrade Ubuntu 16.04 to Ubuntu 18.04. If you are still using Ubuntu version 16.04, you may want to consider updating to the latest Long Term Support release, version 18.04.


What does LTS or Long Term Support Release Mean?

A Long Term Support release or LTS release, means that Ubuntu will support the version for five years. 

If you are running a production environment, you will likely want to use a Long-Term Support version of your preferred server operating system.


What is New in Ubuntu Version 18.04:

1. Depending on when you installed Ubuntu version 16.04, the Linux kernel used would have been anywhere from version 4.4 to 4.10. Version 18.04 uses Linux kernel 4.15 at launch.

2. Linux kernel 4.5 now includes new features like CPU controller for the cgroup v2 interface, AMD secure memory encryption support, the latest MD driver with software RAID enhancements, and improved power management for systems with SATA Link Power Management.

3. The new kernel also includes some Ubuntu-specific updates, Linux security module stacking support, and the signing of POWER host and NV kernels is now supported.

18.04 does not install Python 2 default, and it updated Python version 3 to version 3.6.

4. Apache updates to version 2.4.29 and supports HTTP/2.

5. Nginx updates to version 1.14.0.

6. PHP updates from version 7.1 to 7.2.

7. The ifupdown network manager is removed on new installs and is deprecated. netplan.io is the new network configuration manager.

8. OpenSSH now refuses to use RSA keys smaller than 1024 bits. This command can report the length of a key.

ssh-keygen -l -f /path/to/key.pub

32-bit PowerPC support has been dropped.

9. The Subuquity server installer brings live sessions and fast installs of Ubuntu Desktop to server users.

10. Ubuntu 18.04 ships with LXD system container manager version 3.0. Version 3.0 of LXD allows for clustering of LXD servers, adds support of NVIDIA run-time pass-through, and lxd-p2c is a new tool that turns existing systems into LXD containers.


To Upgrade Ubuntu from 16.04 to 18.04:

1.  Create a backup of your environment.

2. Run the command below to update and upgrade the packages.

$ sudo apt-get update && sudo apt-get upgrade

3. To add the Update Manager to your server add command below to your terminal.

$ sudo apt install update-manager-core

4. Now that you have created a backup installed package updates and have the upgrade manager you are ready to upgrade Ubuntu.

$ sudo do-release-upgrade

5. To check what version of Ubuntu is currently installed use the command below.

$ lsb_release -a

Use Let's Encrypt To Secure Apache2 On Ubuntu - How to do it ?

This article covers method to Secure Apache with Let's Encrypt on Ubuntu 20.04. Let's Encrypt is a certificate authority created by the Internet Security Research Group (ISRG).

It provides free SSL certificates via a fully automated process designed to eliminate manual certificate creation, validation, installation, and renewal.

Certificates issued by Let's Encrypt are valid for 90 days from the issue date and trusted by all major browsers today.


To install Certbot on Ubuntu:

Certbot is a command-line tool that automates the tasks for obtaining and renewing Let’s Encrypt SSL certificates. 

The certbot package is included in the default Ubuntu repositories. 

Update the packages list and install certbot using the following commands:

$ sudo apt update
$ sudo apt install certbot

Before enabling the configuration files, make sure both mod_ssl and mod_headers are enabled by issuing:

$ sudo a2enmod ssl
$ sudo a2enmod headers

Next, enable the SSL configuration files by running the following commands:

$ sudo a2enconf letsencrypt
$ sudo a2enconf ssl-params

Enable the HTTP/2 module, which will make your sites faster and more robust:

$ sudo a2enmod http2

Reload the Apache configuration for changes to take effect:

$ sudo systemctl reload apache2

Install WordPress On Ubuntu 18.04 | 16.04 Servers - Step by Step Process ?

This article covers methods to install WordPress on Ubuntu Linux System. WordPress is undoubtedly one of the most popular Content Management Systems (CMS) available in the market. You can easily install WordPress on Ubuntu 18.04 because it is configured to work with Apache or NGINIX, MySql, PHP in a LAMP or a LEMP stack. 

It also features an extensive plugin framework, and theme system that allows site owners to use the simple and powerful publishing tools.


To Configure Maximum File Size Upload Setting to Allow Larger Files on Ubuntu:

By default, PHP restricts web uploads to under two megabytes.

To allow larger file uploads through the web interface, configure the upload_max_filesize setting in php.ini:

Apache: /etc/php/7.2/apache2/php.ini.
NGINX: /etc/php/7.2/fpm/php.ini.

; Maximum allowed size for uploaded files.

; http://php.net/upload-max-filesize

upload_max_filesize = 2M

Install NetBeans on Ubuntu 20.04 - Step by Step Process ?

This article covers the different methods for the installation of NetBeans on Ubuntu OS.

NetBeans is an open source integrated development environment that comes with good cross-platform support. 

You can configure this tool to support a wide array of development objectives. 

Practically, you can develop Web, Desktop and Mobile Applications without leaving this platform.

Besides this, the user can add a wide array of known languages such as PHP, C, C++, HTML, Ajax, JavaScript, JSP, Ruby on Rails  and so on.


To install Netbeans IDE on any Linux distribution using Snap.

Snap is a universal package manager and if you have enabled Snap on your distribution, you can install it using the following command:

$ sudo snap install netbeans --classic

Install phpMyAdmin with Apache on Ubuntu 20.04 - Step by Step Process ?

This article covers how you can  seamlessly install phpMyAdmin on your Ubuntu Linux system.

Working with a database can sometimes be intimidating, but PhpMyAdmin can simplify tasks by providing a control panel to view or edit your MySQL or MariaDB database.

To Install phpMyAdmin on Ubuntu:
1. Update the apt package tool to ensure we are working with the latest and greatest.

$ apt update && upgrade

2. Install PhpMyAdmin and PHP extensions for managing non-ASCII string and necessary tools.

$ apt install phpmyadmin php-mbstring php-gettext

During this installation you’ll be asked for the web server selection, we will select Apache2 and select ENTER.
Here, you have the option for automatic setup or to create the database manually.
For us, we will do the automatic installation by pressing ENTER for yes.
3. At this setup, you'll be asked to set the PhpMyAdmin password.
Specifically for the PhpMyAdmin user, phpmyadmin,  you'll want to save this in a secure spot for later retrieval.
4. Enable PHP extension.

phpenmod mbstring

5. Restart the Apache service to recognize the changes made to the system.

# systemctl restart apache2

Access Google Drive on Ubuntu 20.04 LTS - Step by Step Process ?

This article covers how you can access Google drive on Ubuntu. Now you can easily access your Google Drive files directly from the File Manager.

The process involves adding your online Google account to your Gnome Online Accounts list. This configuration then lets you mount your Google Drive account to your Nautilus File Manager. 

After mounting, you can access your online files, edit them, and add new files directly from your Ubuntu to your Google Drive.


To Install and Open Gnome Online Accounts:

1. Open the Ubuntu command line, the Terminal, either through the system Dash or the Ctrl+Alt+T shortcut. 

2. Once the Terminal application opens, enter the following command as sudo:

$ sudo apt install gnome-online-accounts

Please remember that only an authorized user can add, remove and configure software on Ubuntu.

3.  Once the utility is installed on your system, you can open it through one of the following methods:

By entering the following command in your Terminal:
$ gnome-control-center online-accounts

Install Python 3.9 on Ubuntu 20.04 - Step by Step Process ?

This article covers how to install and compile Python3.9 using different methods, using PPA repo, compiling it from the source code, and installing it using the Linuxbrew tool.

We can now start using Python 3.9 for our projects.

Python is a high-level programming language, mostly used to write scripting and automation. It is a very popular language known for its simplicity and easy syntax. 

Python one of the best language for for artificial intelligence (AI).


To Install Python 3.9 on Ubuntu 20.04 using APT:

1. Update package list, type:

$ sudo apt update

2. Install software-properties-common package to easily manage distribution and independent software vendor software sources:

$ sudo apt install software-properties-common
$ sudo add-apt-repository ppa:deadsnakes/ppa

3. Now install python 3.9 using apt command:

$ sudo apt-get install python3.9

4. The following command can help to identify the proper install location of Python:

$ which python3

The execution of the above command produces the following output on console:

/usr/bin/python3

Install MongoDB on Ubuntu 20.04 LTS - Step by Step Process ?

This article covers how to install MongoDB on Ubuntu 20.04 LTS using either the apt package manager or by downloading and installing through the archive. For more information, visit MongoDB's official documentation.


MongoDB is an open-source and cross-platform document-oriented database system written in C++. It stores data in collections of JSON-like, flexible documents and used to create powerful websites and applications. 

Due to its scalability and high performance, it is used for building modern applications that require powerful, mission-critical and high-availability databases.


To Configure MongoDB on Ubuntu:

MongoDB default configuration file is located at /etc/mongod.conf

By default, each user will have access to all databases and perform any action. 

For production environments, it is recommended to enable the MongoDB authentication.

i. You can do it by editing the file /etc/mongod.conf:

$ nano /etc/mongod.conf

2. Add the following lines:

security:
  authorization: enabled

3. Save and close the file then restart the MongoDB service to apply the changes:

$ systemctl restart mongod


Advantages of MongoDB:

1. Absence of a schema

2. Based on the collections of various documents

3. A clear structure of every object

4. Highly scalable

5. Internal memory is used to store data, which lets us get data faster.

6. Data is stored as JSON objects.

7. MongoDB supports document-based queries

Install FileZilla on Ubuntu 20.04 LTS - Step by Step Process ?

This article covers how to install FileZilla on Ubuntu 20.04 LTS system. Also we mentioned the steps to remove FileZilla in case you need to so.

FileZilla is a ftp client for both windows & linux operating system. It is a powerful client for plain FTP, FTP over SSL/TLS (FTPS) and the SSH File Transfer Protocol (SFTP). 


To Install FileZilla from command line on Ubuntu / Debian:

Use the following commands.

$sudo apt-get update
$sudo apt-get install filezilla

First command synchronizes the configured repositories.

This command is used to ensure that always the latest version of the software is installed.

Install IntelliJ IDEA on Ubuntu 20.04 LTS - Step by Step Process ?

This article covers the different methods to install IntelliJ IDEA on Ubuntu 20.04 Linux system. Basically, In developing Java applications, IntelliJ IDEA is arguably one of the most ergonomic and formidable IDEs there is. 

It ships with all the right tools and a set of plugins to make coding a seamless exercise.


To Install IntelliJ IDEA from command line on Ubuntu:

1. Start by opening a terminal window and execution of the bellow apt command. Select your preferred version to install:

$ sudo snap install intellij-idea-community --classic

OR

$ sudo snap install intellij-idea-ultimate --classic

OR

$ sudo snap install intellij-idea-educational --classic

2. You can start the IntelliJ IDEA using the below command:

$ intellij-idea-community

OR

$ intellij-idea-ultimate

OR

$ intellij-idea-educational

Install Atom Editor on Ubuntu 20.04 - Step by step process ?

This article covers the different methods to install Atom editor on Ubuntu 20.04 system. Atom is an open-source text and source code editor for Windows, Linux, and macOS, developed by GitHub. 

It is called "A hackable text editor for the 21st century" due to being a highly customizable text editor.


To Install Atom Editor using Snap:

1. First, install the Snap package manager on your system if it is not already installed.

$ sudo apt update && sudo apt install -y snapd

2. Then, install Atom editor with the snap command.

$ sudo snap install atom --classic

Configure WordPress on Ubuntu Server with Apache - Step by step process to do it ?

This article covers setup WordPress — including Apache, MySQL, and PHP, on the Ubuntu Linux server. WordPress is the most popular CMS (content management system) on the internet. It allows you to easily set up flexible blogs and websites on top of a MySQL backend with PHP processing. WordPress has seen incredible adoption and is a great choice for getting a website up and running quickly. After setup, almost all administration can be done through the web frontend.


How to install PHP Extensions on Ubuntu?

1. You can download and install some of the most popular PHP extensions for use with WordPress by executing the commands:

$ sudo apt update
$ sudo apt install php-curl php-gd php-mbstring php-xml php-xmlrpc php-soap php-intl php-zip

2. Then restart Apache to load these new extensions in the next section. 

If you are returning here to install additional plugins, you can restart Apache now by running:

$ sudo systemctl restart apache2


To install WordPress on Ubuntu:

1. Change into a writable directory and then download the compressed release by typing:

$ cd /tmp
$ curl -O https://wordpress.org/latest.tar.gz

2. Extract the compressed file to create the WordPress directory structure:

$ tar xzvf latest.tar.gz

3. Add a dummy .htaccess file so that this will be available for WordPress to use later.

Create the file by typing:

$ touch /tmp/wordpress/.htaccess

4. Copy over the sample configuration file to the filename that WordPress actually reads:

$ cp /tmp/wordpress/wp-config-sample.php /tmp/wordpress/wp-config.php

5. Create the upgrade directory, so that WordPress won't run into permissions issues when trying to do this on its own following an update to its software:

$ mkdir /tmp/wordpress/wp-content/upgrade

6. Copy the entire contents of the directory into our document root:

$ sudo cp -a /tmp/wordpress/. /var/www/wordpress

Configure XRDP to Securely Connect Remote Linux Servers - Step by step process ?

This article covers how to install and use XRDP to securely connect to remote servers. Xrdp is an open-source implementation of the Microsoft Remote Desktop Protocol (RDP) that allows you to control a remote system graphically. 

With RDP, you can log in to the remote machine and create a real desktop session the same as if you had logged in to a local machine.


Installing Xrdp on Debian:

Xrdp package is available in the standard Debian repositories. To install it, run:

$ sudo apt install xrdp 

The service will automatically start once the installation process is complete. You can verify that the Xrdp service is running by typing:

$ sudo systemctl status xrdp


How to Configure Xrdp on Linux?

The Xrdp configuration files are stored in the /etc/xrdp directory.

Whenever you make any changes to the configuration file you need to restart the Xrdp service:

$ sudo systemctl restart xrdp

Install Nginx on Ubuntu 20.04 - Step by Step process to implement it ?

This article covers how to install Nginx on the Ubuntu system. Also, you will learn how to configure the firewall and manage Nginx services. 

Finally, you will see how to uninstall Nginx in case you no longer need it in your system.

Nginx is a free, open-source Linux application for web servers. It works as a reverse proxy server by directing web traffic to specific servers.

Also, Nginx is used for security and load-balancing, but can also function independently as a web server.


To Install Nginx From Ubuntu Repositories:

1. Update Software Repositories

It is important to refresh the repository lists before installing new software. This helps make sure that the latest updates and patches are installed.

Open a terminal window and enter the following:

$ sudo apt-get update

2. Nginx is included in the Ubuntu 20.04 default repositories. Install it by entering the following command:

$ sudo apt-get install nginx


How to manage Nginx on Ubuntu ?

The behavior of Nginx can be adjusted. Use this to start or stop Nginx, or to enable or disable Nginx at boot.

Start by checking the status of the Nginx service:

$ sudo systemctl status nginx

If the status displays active (running), Nginx has already been started. 

Press CTRL+z to exit the status display.

If Nginx is not running, use the following command to launch the Nginx service:

$ sudo systemctl start nginx

To set Nginx to load when the system starts, enter the following:

$ sudo systemctl enable nginx

To stop the Nginx service, enter the following:

$ sudo systemctl stop nginx

To prevent Nginx from loading when the system boots:

$ sudo systemctl disable nginx

To reload the Nginx service (used to apply configuration changes):

$ sudo systemctl reload nginx

For a hard restart of Nginx:

$ sudo systemctl restart nginx

To Test the Configuration

$ sudo nginx –t

The system should report that the configuration file syntax is OK, and that the configuration file test is successful.

Install Skype on Ubuntu 20.04 - Step by Step process to perform it ?

This article covers the different methods to install Skype on Ubuntu 20.04 LTS including both the GUI and the command line. 


To install the Skype snap, open your terminal (Ctrl+Alt+T) and run the following command:

$ sudo snap install skype --classic

That's it. You have installed Skype on your Ubuntu machine, and you can start using it.


How to install Skype with apt on Ubuntu ?

Skype is available from the official Microsoft Apt repositories. To install it, follow the steps below:

1. Open your terminal and download the latest Skype .deb package using the following wget command:

$ wget https://go.skype.com/skypeforlinux-64.deb

2. Once the download is complete, install Skype by running the following command as a user with sudo privileges :

$ sudo apt install ./skypeforlinux-64.deb

You will be prompted to enter your password.

3. When a new version is released, you can update the Skype package through your desktop standard Software Update tool or by running the following commands in your terminal:

$ sudo apt update

$ sudo apt upgrade

Install Mozilla Firefox on Ubuntu 20.04 - How to do it ?

This article covers how to install the Mozilla Firefox browser on the Ubuntu system. Mozilla Firefox is the official Internet browser for Ubuntu, therefore, most Ubuntu distros have it installed by default.

If your system lacks this browser due to any reason or if you have accidentally deleted it, we will tell you how to install it on your Ubuntu.


To update Firefox on Linux:

1. Click the menu button , click. Help and select About Firefox. On the menu bar click the Firefox menu and select About Firefox.

2. The About Mozilla Firefox Firefox window opens. Firefox will check for updates and download them automatically.

3. When the download is complete, click Restart to update Firefox.


To Delete Firefox and all it's data from Ubuntu:

1. run sudo apt-get purge firefox.

2. Delete /etc/firefox/ , this is where your preferences and user-profiles are stored.

3. Delete /usr/lib/firefox/ should it still be there.

4. Delete /usr/lib/firefox-addons/ should it still be there.

Install Spotify on Ubuntu 20.04 - Step by Step process to do it ?

This article covers the different methods of installation of Spotify on the Ubuntu 20.04 system. 

Spotify is a Popular music streaming application used globally and users can use any of the methods discussed above for its installation. 

The uninstallation process is also quite easy and we covered it for the ease of our readers. 

Users can also update Spotify with each newly released version.


Where is Spotify installed Linux?

If you followed the instructions on https://www.spotify.com/download/linux/ and installed from Ubuntu Software or snap, it should be located at /snap/bin/spotify . 

If you installed the debian package, it should be located at /usr/bin/spotify .


To update Spotify on Ubuntu:

1. Update list of available packages:

$ sudo apt-get update.

2. Install Spotify:

$ sudo apt-get install spotify-client.


To uninstall Spotify on Linux:

1. Quit Spotify.

2. Uninstall. sudo apt-get remove spotify-client.

3. Remove old config and cache.

cd $HOME/.config. rm -r spotify. cd $HOME/.cache. rm -r spotify.

4. Reinstall by following instructions on https://www.spotify.com/download/linux. 


To Install via command line on Ubuntu:

If you don't have access or don't want to use Ubuntu Software, it is possible to install Spotify from the command line with snap. 

Run the following command in your terminal:

$ snap install spotify

Process to configure an NTP server and client on Ubuntu 20.04 LTS ?

This article will guide you on how to configure the NTP server on the #Ubuntu machine and then sync a clock of NTP client machine. Now you can easily set up NTP server and connect multiple client machines with it for time synchronization.

The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.

NTP is intended to synchronize all participating computers to within a few milliseconds of Coordinated Universal Time (UTC).


How do I start #NTP on Linux?

In order to add command line options to the ntpd service (/etc/init. d/ntpd), one has to edit /etc/sysconfig/ntpd file and add the desired option to the OPTIONS variable, and restart the service via 'service ntpd restart'.


What port does NTP use?

NTP time servers work within the TCP/IP suite and rely on User Datagram Protocol (UDP) port 123. NTP servers are normally dedicated NTP devices that use a single time reference to which they can synchronize a network. 

This time reference is most often a Coordinated Universal Time (UTC) source.


To Sync NTP client with server via command line:

1. Edit the /etc/ntp.

2. Search for the lines beginning server .

3. Replace the server entries with the IP address or hostname of the NTP server or servers with which you want to synchronize.

4. Save the file.

5. Configure the NTP client service to start at run level 3 when the appliance boots.

Install VirtualBox on Ubuntu 20.04 LTS - Step by step process ?

This article will guide you on the different methods to #install #VirtualBox on Ubuntu 20.04 system. Now, you can create your first guest Linux machine or Windows environment on your Ubuntu system. 

#Xen is a popular, open-source virtual machine application that is officially supported by #Ubuntu. 

It provides high performance, but only supports a small number of host and guest operating systems. 

Ubuntu is supported as both a host and guest operating system, and Xen is available in the universe software channel.

If you want to explore more about the working of the Virtualbox then, you can visit the Official documentation of Virtualbox use from this page .

VirtualBox can be installed on #Windows, Linux, macOS, Solaris, and FreeBSD.


To find the #Linux version:

1. Open the terminal application (#bash shell).

2. For remote server login using the ssh: ssh user@server-name.

3. Type any one of the following command to find os name and version in Linux: cat /etc/os-release. lsb_release -a. hostnamectl.

4. Type the following command to find Linux kernel version: uname -r.

Install MongoDB ( NoSQL ) on Linux (Ubuntu 20.04) - Step by step process ?

This article will guide you on how to add MongoDB’s official #repository and install the latest stable release of MongoDB #NoSQL in the #Ubuntu 20.04 LTS system. 

Also, you will learn how to completely uninstall from the system in case you no longer need it.

MongoDB stores data in db folder within data folder. But, since this data folder is not created automatically, you have to create it manually. 

Remember that data directory should be created in the root (/).

To get stats about #MongoDB server, type the command db. stats() in MongoDB client. 

This will show the database name, number of collection and documents in the database.

In MongoDB, data is stored as documents. 

These documents are stored in MongoDB in JSON (JavaScript Object Notation) format. 

#JSON documents support embedded fields, so related data and lists of data can be stored with the document instead of an external table.

Step by step process to install and configure Odoo ERP on Ubuntu 20.04 LTS ?

This article will guide you on how to install and configure the Odoo14 on #Ubuntu 20.04 system. Also you will learn how to install required #PostgreSQL and wkhtmltopdf packages on your system. 

1. Odoo Community Edition is the free basic version of Odoo supported by open source software. 

2. #Odoo #CRM (Customer Relationship Management) system is a powerful browser-based sales software designed to increase organisational efficiency. Odoo, contains all of the applications that your sales, marketing, accounts department and management teams need in the one place.

3. Once all dependencies are set up, Odoo can be launched by running odoo-bin , the command-line interface of the server. It is located at the root of the Odoo Community directory.

4. Once Odoo installed, you can verify the service is up and running and is enabled to automatically start at system #boot. 

5. By default, Odoo listens on port 8069 and you can verify it using the netstat or ss tools. 

This is another way to confirm that Odoo is up and running.

Step by step process to install and configure HAproxy on Ubuntu 20.04 LTS ?

This article will guide you on how to #install and configure #HAproxy load balancer on the #Linux system. 

You will learn the basic setup and configuration of HAproxy as a load balancer for #Apache web servers. Also, we looked at some commands for managing the HAproxy server. In the end, we tested the load balancing through the browser and the #curl command. 

HAProxy is free, open source #software that provides a high availability #load #balancer and proxy server for #TCP and HTTP-based applications that spreads requests across multiple servers.

To Deploy on Linux :

1. Download the source code of HAProxy.

2. Unzip the file into the desired location tar xvzf haproxy-1.8-dev1.

3. Compile the source code.

4. Create config file haproxy.cfg with the configuration details.

5. Start the haproxy with ./haproxy -f haproxy.

6. Access the status page on http:localhost:9999/stats.

Steps to install XAMPP Server on Linux Mint 20 ?

This article will guide you on steps to install #XAMPP on Linux Mint 20. You will also learn the method of uninstalling XAMPP web server whenever you feel like it.

The #htdocs folder can be found in /opt/lampp/ . You can navigate to your root folder from the file manager (nautilus by default), by clicking on Other locations from the sidebar, then #Computer . From there you can find the opt folder that contains the lampp folder.

To install xampp in MX #Linux:

1. Click XAMPP for Linux. It's in the middle of the page.

2. Allow the download to complete.

3. Open #Terminal.

4. Change over to the "Downloads" directory.

5. Make the downloaded file executable.

6. Enter the installation #command.

7. Enter your password when prompted.

8. Follow the installation prompts.

Steps to install Google Chrome in Ubuntu 20.04 LTS ?

This article will guide you on the different methods to #install #Google #Chrome on #Ubuntu 20.04 system using two different ways using the command line and graphical methods. We have executed different commands on the terminal for the installation.

To Install Google Chrome on Ubuntu Graphically:

1. Click on Download Chrome.

2. Download the DEB file.

3. Save the DEB file on your #computer.

4. Double click on the downloaded DEB file.

5. Click Install button.

6. Right click on the deb file to select and open with Software Install.

7. Google Chrome installation finished.

Steps to start, stop or restart services in Ubuntu 20.04 LTS ?

This article will guide you steps on how you stop, start, or restart a #service in #Ubuntu 20.04. service operates on the files in /etc/init. d and was used in conjunction with the old init system. #systemctl operates on the files in /lib/systemd . If there is a file for your service in /lib/systemd it will use that first and if not it will fall back to the file in /etc/init. To list all loaded services on your system (whether active; running, exited or failed, use the list-units subcommand and --type switch with a value of service. To Check running process in #Linux: 1. Open the #terminal #window on Linux. 2. For remote Linux server use the ssh command for log in purpose. 3. Type the ps aux command to see all running process in Linux. 4. Alternatively, you can issue the top command or htop command to view running process in Linux.

How to install Notepad++ on Ubuntu 20.04 LTS ?

This article will guide you on steps to install #Notepad++ on Ubuntu 20.04 #Linux operating system using snap package manager. Notepad++ is a #GUI based user friendly text editor that can be used on #Linux as well as on Windows platform. To #Install Notepad++ on Ubuntu 20.04 : 1. Install Notepad++ on Ubuntu 20.04. Notepad++ runs over the WINE platform, which provides compatibility for the Windows application on Unix-like operating systems. 2. Open Notepad++. 3. Uninstall Notepad++.

How to use Linux command to delete the PREROUTING rule in iptables ?

This article will guide you on how to list and remove/delete iptables pretrouting chain nat rules on your #Linux based system. The -D or --delete option delete one or more rules from the selected chain. There are two versions of this #command, the rule can be specified as a number in the chain or a rule to match. One of the ways to delete #iptables #rules is by rule specification. To do so, you can run the iptables command with the -D option followed by the rule specification.

Steps to Install and Configure Nginx on Ubuntu Linux 18.04 LTS?

This tutorial will guide you on how to get Nginx server installed and configured on an Ubuntu Linux 18.04 LTS server.

Nginx is one of the most popular web servers in the world and is responsible for hosting some of the largest and highest-traffic sites on the internet. It is more resource-friendly than Apache in most cases and can be used as a web server or reverse proxy.


Nginx Configuration Files Structure

  • All configuration files are located in the /etc/nginx/ directory.
  • Nginx main configuration file is at /etc/nginx/nginx.conf.
  • It's best practice to create a separate configuration file of each domain for better maintainability.
  • New server blocks (configuration file) of each domain should be stored in /etc/nginx/sites-availabledirectory. You need to make symlink of these configuration files at /etc/nginx/sites-enabled to take in used by Nginx.
  • Activating server blocks is done by creating a symlink (a pointer) from the configuration file sites in a /etc/nginx/sites-enabled directory to the sites-enabled directory.
  • The default server web root directory is /var/www/html
  • It's best practice to to follow standard naming convention. Nginx server block files name should as domain name and must end with .conf extension. For example, your domain name is example.com then server block file name should example.com.conf
  • Nginx log files (access.log and error.log) are located in the /var/log/nginx/ directory. It's also recommended to have a different access and error log files for each server block.

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