An NTP server is important because it allows all devices on a network to be synchronized via a clock. That is, they all have the same time and time zone. This may seem unimportant, but the correct functioning of many services depends on proper time settings.

Now, there is a tool called Chrony that allows us to quickly deploy an NTP server.

According to the Chrony website:

Chrony is a versatile implementation of the Network Time Protocol (NTP). It can synchronize the system clock with NTP servers, reference clocks (e.g. GPS receiver), and manual input using wristwatch and keyboard. It can also operate as an NTPv4 (RFC 5905) server and peer to provide a time service to other computers in the network.

Fortunately, it has good support for many Linux distributions and Ubuntu is no exception.

Chrony on Ubuntu 20.04

Before starting, the server must have the time zone set correctly.

So, open a terminal or connect via SSH.

sudo timedatectl set-timezone Europe/Berlin

Replace Europe/Berlin with the correct timezone for your server.

To check the changes, run the command timedatectl.

Output:

               Local time: Wed 2021-05-12 21:13:11 CEST
           Universal time: Wed 2021-05-12 19:13:11 UTC 
                 RTC time: Wed 2021-05-12 19:13:12     
System clock synchronized: yes                         
              NTP service: active                      
                Time zone: Europe/Berlin (CEST, +0200) 
          RTC in local TZ: no 

Now we can install the chrony package from the official Ubuntu 20.04 repositories.

sudo apt update
sudo apt install chrony
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  systemd-timesyncd
The following NEW packages will be installed:
  chrony
0 upgraded, 1 newly installed, 1 to remove and 11 not upgraded.
Need to get 220 kB of archives.
After this operation, 290 kB of additional disk space will be used.
Do you want to continue? [Y/n]

The program is quite lightweight so the installation will take almost no time at all.

So, start the Chrony service and have it start with the system.

sudo systemctl start chronyd
sudo systemctl enable chronyd

Check the status of the service

sudo systemctl status chronyd
● chrony.service - chrony, an NTP client/server
     Loaded: loaded (/lib/systemd/system/chrony.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2021-05-12 21:16:25 CEST; 1min 36s ago
       Docs: man:chronyd(8)
             man:chronyc(1)
             man:chrony.conf(5)
   Main PID: 1815 (chronyd)
      Tasks: 2 (limit: 2286)
     Memory: 1.0M
     CGroup: /system.slice/chrony.service
             ├─1815 /usr/sbin/chronyd -F -1
             └─1816 /usr/sbin/chronyd -F -1

May 12 21:16:25 osradar systemd[1]: Starting chrony, an NTP client/server...
May 12 21:16:25 osradar chronyd[1815]: chronyd version 3.5 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SIGND +ASYNCDNS +SECHASH +IPV6 -DEBUG)
May 12 21:16:25 osradar chronyd[1815]: Initial frequency -38.890 ppm
May 12 21:16:25 osradar chronyd[1815]: Loaded seccomp filter
May 12 21:16:25 osradar systemd[1]: Started chrony, an NTP client/server.
May 12 21:16:32 osradar chronyd[1815]: Selected source 2001:67c:1560:8003::c7
May 12 21:17:38 osradar chronyd[1815]: Selected source 2001:1600:4:1::123

And you will know that the service is running correctly.

Configuring Chrony on Ubuntu 20.04

Now that we have the service installed, we need to configure it. The Chorny configuration file is /etc/chrony/chrony.conf which we need to modify but first make a backup of it.

sudo cp /etc/chrony/chrony/chrony.conf `/etc/chrony/chrony.conf.bak

And now edit it:

sudo nano /etc/chrony/chrony.conf

And set the nearest NTP servers

server [NTP server]

Then save the changes and close the editor.

Now do the synchronization

sudo timedatectl set-ntp true

After that, restart the Chrony service.

sudo systemctl restart chronyd

Then, test the changes by checking the Chrony sources

chronyc sources

Output

210 Number of sources = 8
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^- golem.canonical.com           2   6    37     5  +6082us[+6082us] +/-   54ms
^- chilipepper.canonical.com     2   6    67     3   +313us[ +313us] +/-   47ms
^- alphyn.canonical.com          2   6    37     5   +892us[ +892us] +/-  119ms
^+ pugot.canonical.com           2   6    37     4  +1452us[+1452us] +/-   71ms
^* 25000-021.cloud.services>     2   6    37     6   +881us[  -83us] +/-   48ms
^- ns1.luns.net.uk               2   6    37     4  +2533us[+2533us] +/-   67ms
^+ 2a01:4f8:c2c:3d20::1          3   6    37     4  -1651us[-1651us] +/-   93ms
^+ time02.nevondo.com            2   6    37     4  +1028us[+1028us] +/-   43ms

So, everything is correct.

Note: I am uing the default server. In this output, you will see the server that you added.

Configuring the Chrony Client

Now it’s time to do the client configuration. Regardless of the Linux distribution you use, you have to set the Timezone correctly.

sudo timedatectl set-timezone Europe/Berlin

Proceed now to install the client on your distribution.

For example, on CentOS it would be

sudo dnf install chony

Or on Debian based distributions:

sudo apt install chrony

Next, you have to configure Chrony to serve the server you have configured.

sudo nano /etc/chrony/chrony.conf

And add the Chrony server:

server chrony-server-ip

Save the changes and close the editor. Now synchronise your computer with the created NTP server.

sudo timedatectl set-ntp true

You can also verify the changes by running

chronyc sources

So, enjoy it.

Conclusion

An NTP server is a simple tool to set up but it will help you to keep everything in order on your network. This step is essential for many computer systems.

The post A NTP Server by installing Chrony on Ubuntu 20.04 appeared first on Linux Windows and android Tutorials.

The Sensu agent is a lightweight client that runs on the infrastructure components you want to monitor. The Sensu agent is available for Linux, macOS, and Windows

Install Sensu GO agent on Ubuntu 20.04

First, make sure you update your distribution:

sudo apt update
sudo apt upgrade

You also need to install some necessary packages:

sudo apt install curl gnupg unzip wget

Then, you should add the Sensu repository so that we can install the agent without problems.

curl -s https://packagecloud.io/install/repositories/sensu/stable/script.deb.sh | sudo bash

After that, you can install the agent without problems.

sudo apt install sensu-go-agent

Similarly, we have to download the initial configuration file of the agent and copy it to the appropriate path.

sudo curl -L https://docs.sensu.io/sensu-go/latest/files/agent.yml -o /etc/sensu/agent.yml

This file needs to be modified, but first, make a backup of it.

sudo cp /etc/sensu/agent.yml /etc/sensu/agent.yml.bak

And edit it to define the IP address where Sensu Backend is installed.

sudo nano /etc/sensu/agent.yml

And leave it as shown in the image:

Replace the IP by yours.

Now you can start the Sensu agent service and check its status.

systemctl start sensu-agent
systemctl status sensu-agent

There are many configurations available for the agent file at this link. Every time you modify the configuration file you have to restart the service to apply the changes.

It should now be visible from the backend. If not, you will probably need to restart the service.

Conclusion

Sensu Go is a very good tool that allows us to monitor services and nodes. This makes it interesting at a professional level. That is why it is recommended to take a look at it.

The post Install the Sensu GO agent on Ubuntu 20.04 appeared first on Linux Windows and android Tutorials.

Nextcloud: a great solution for privates clouds

There are many data storage services in clouds. Technological giants like Apple, Google and Microsoft have them. However, there are people or companies that want to have absolute control of their own data. Nextcloud is there for that.

Nextcloud is an open-source web application that allows us to create our own private cloud. It was created with the primary objective that it is the user who has absolute control of the files.

Many companies install Nextcloud on their servers to create their private clouds. This way they can rely on their own data management. It is even of great help in educational or personal projects.

Getting the Nextcloud desktop client on Linux

The first thing we need to do is to have a Nextcloud server running. About that, we have some posts that can help you.

How to install Nextcloud on Ubuntu 20.04?
Nextcloud using Docker compose
Install Nextcloud on CentOS 8 /RHEL 8 / Oracle Linux 8
Install Nextcloud on Debian 10

This server has to be ready for battle. Whether on the internet or on an internal network.

After you already have it or if it already exists, you have to go to the Nextcloud website.

And look in the download section, the desktop client, and choose the version for Linux in AppImage format.

Once you download it, assign execution permissions from the file browser of your distribution.

In case you want to do it from the terminal, you just have to navigate to the folder where it is and assign it the permission.

cd Downloads/
chmod +x Nextcloud-3.0.2-x86_64.AppImage

And then, run it by double-clicking on it.

You will see the following screen

Choose the Login option to start the configuration process. The first thing is to define the server and then click on next.

This way you can configure the type of synchronization, folders to synchronize, and so on.

Then, you can check the application options.

Conclusion

Nextcloud is a very useful tool for small and medium businesses that want to create a private cloud quickly and securely. A secure operating system such as Linux is also required.

So, share this post and join our Telegram channel and our Facebook page. Also, buy us a coffee 😉

The post How to get the Nextcloud desktop client on Linux? appeared first on Linux Windows and android Tutorials.

First of all, it is important to remember that it is IRC. Internet Relay Chat is a real-time communications protocol. Using IRC, users should not establish communication beforehand, so that all users on a channel can communicate with each other, even if they have had no previous contact. Widely used for discussions and technical support of many open source projects.

The lounge is a web-based IRC client. It has many modern features such as push notifications. Besides being open source, it is also cross-platform because it can be installed on various operating systems such as Windows, Linux or Mac OS. On the other hand, the application has a new responsive graphical interface, which makes it ideal for daily use, all this without sacrificing performance.

So, let us start.

1.- Upgrade the system

This is an essential step if you want to keep your operating system stable and robust. Therefore, it is always advisable to do it frequently.

Open a terminal and run the following command:

:~$ sudo apt update && sudo apt upgrade

Upgrading the system is important because you will install all the necessary security patches to improve system security. Above all in a production machine.

2.- Install Node.js

The next step to install this modern IRC client is to have node.js installed. The Lounge is built with web technologies, and part of those technologies includes node.js.

The application requires at least version 6.

So, in this post, you will learn to install node.js on Ubuntu 20.04.

3.- Install YARN

YARN is dependency management that focuses on speed, reliability, and security. Using YARN we will be able to install the latest stable version of The Lounge in an easy way.

So, run these commands:

:~$ curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
OK
:~$ echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list

Next, install it.

:~$ sudo apt update && sudo apt install yarn

So, Node.js and YARN are correctly installed.

4.- Getting The Lounge on Ubuntu 20.04

Now it’s your turn to install The Lounge, so use YARN.

:~$ sudo yarn global add thelounge

Once you have finished the installation process run The Lounge with this command:

:~$ thelounge start

Then, you will see this.

After that, open your web browser and go to http://localhost:9000/ or http://SERVER_IP:9000.

5.- Create a new user for the Lounge

Now in order to enjoy The Lounge, it is necessary to create a new user. Stop, go to the terminal, and press CTRL + C to end the execution of The Lounge. And type the following.

:~$ thelounge add angelo

This command will create the angelo user and then you will be prompted to create the password and an option about the logs.

Start The Lounge again:

:~$ thelounge start

And come back to the web browser, and log in. You will see this:

On the previous screen, you will see the IRC options. You will be able to configure the nickname, the server, and the channel to use. Once you have done it, you can click on the connect button.

So, that is it.

Conclusion

The Lounge is a modern IRC client that comes to return faith in this protocol that allows people to discuss and interact for common purposes. Its installation is within the reach of a few commands and its use is well worth it.

Share this article with your friends. And join our Telegram Channel. Also, you can buy us some coffees.

The post Install The Lounge on Ubuntu 20.04. A modern client for IRC. appeared first on Linux Windows and android Tutorials.