How Can Common Applications and Services be Deployed Using Linux Servers?
Originally published at https://www.niit.com/india/.
An operating system is an integral part of complex IT systems. Having a reliable, performance-driven and upgradeable operating system becomes a prerequisite for every successful IT deployment. Linux servers stand true on all these factors. All the IT workloads and deployments, be it traditional or innovative, have found their stable foundation in Linux.
An introduction to Linux
Originally created just as a hobby by Linus Torvalds in 1991, Linux is the most commonly used open-source operating system. Linux also acts as software and receives requests from the requests-based programs to the hardware of the computer. Since it is an open-source server, Linux can be released under the General Public License. Simply stated, this server can easily be run, shared, studied, and modified by anyone. One can also redistribute and sell the modified code (only under the existing license). In comparison to the existing conventional operating systems like Unix and Windows, Linux is quite different. The traditional ones are proprietary, locked down, unmodifiable, and delivered in a raw state as compared to the modern operating system — Linux. It software courses offered by NIIT can give you a better insight into Linux
Functions of Linux
Be it any kind of IT initiative, Linux is the best fit to be the base of cloud-native applications, containers, and security. Several world’s renowned companies and businesses like Wikipedia, New York Stock Exchange, etc. rely on the specific usage of Linux Kernel’s distribution. The Linux server has budded tremendously in respect to being highly available, trustworthy, and critical workloads in data centers and cloud deployments. According to the needs and workloads, the Linux server has multiple use cases, target systems, distributions, and devices and capabilities.
The tech giant Microsoft has brilliantly incorporated Linux in several ways along with the production of a SQL Server for Linux and taking the .NET framework as an open-sourcing platform. This is conducted so that every platform can easily run it and broadens the scope for the developers to build applications with a similar framework. To learn more on Linux check out the Post Graduate Programme in Full Stack Software Engineering at NIIT.
Who uses Linux?
Many people use Linux even unknowingly. It totally depends on the type of survey you are looking at. Usually, Linux is chosen by companies and even individuals to act as their server because of the security, flexibility and span of users it provides. Devices like Android phones, tablets, personal video recorders, Chromebooks, digital storage devices, wearables, and cameras also run on Linux. Even your car comprises Linux under the hood. Microsoft’s Windows uses Linux components as Windows Subsystem.
With that being said about Linux, its uses, functions, and whatnot, let’s hop on to how it can be successfully deployed.
Deployment steps for Linux services and their related tools
Be it bringing a basic website into effective action using Apache or making use of a new file server relying on NFS, successful deployment is a must. Let’s dive into the basic steps that will help you know about the deployment of Linux servers better. Have a look:
Step 1: Make sure that the service is installed!
It goes without saying that service installation is the foremost step of all this process. Some of the Linux distributions involve only a minimal installation of services just because of performance and security reasons.
For instance: Imagine that the only network service you can rely on is the installation using the default SSH. In such a case, when an Apache webserver or NFS file server is deployed, you can install the software all by yourself.
However, remember that when you are installing most of the applications, you get access to the latest version. You also get the freedom to utilize old software versions if they are required for compatibility reasons.
In the case of RHEL-based distributions, make sure that the service installation is conducted with the help of rpm, yum, or dnf commands.
For example, The following yum command can be run in order to make sure that the Apache software is installed.
#yum list httpd
Step 2: Watch out for the service configuration!
As you already know, text files are used to manage service configuration in Linux. The location of these files is usually the /etc directory. Once you successfully install the service, you will have to edit the associated configuration files in order to configure it completely.
For example: Have a look at the primary configuration file of Apache:
\/etc/httpd/conf/httpd.conf
This file should be used to give an outline to the web service’s initial settings.
Most of the sysadmins use vim to make edits in the configuration files. Some of the possible tools are Nano, Gedit, and Emacs.
Following is an example of opening a configuration file that uses the text editor — vim:
# vim/etc/https/conf/httpd.conf
Step 3: Check out if the service has started or not!
The newly installed and configured services must be started. Starting a service manually will lead to the reading of the file you must have edited in the initial step. The initial procedure makes the functionality available by launching the appropriate processes.
As several modern distributions are based on system, stopping and restarting the services would require using the systemctl command:
# systemctl start httpd
If the older systems are relying on Sysv init environment then use the below-mentioned command to commence the service:
# service https start
However, an issue lies while manually starting any service — it remains active only for a short span of time, the current runtime. The process will not automatically start if you reboot the server.
Step 4: Check the persistence of the service!
Whenever you want to start the service, the system gets booted up and you then have to enable it. Commencing the service can cause the system to start.
Manage the startup status of the service with the help of systemctl.
For example:
# systemctl enable httpd
Use the chkconfig command in order to control the status of the service based on the SysV-based systems.
For example: To make sure that the service is started on the run levels of 3 and 5, use this command:
# chkconfig — level 35 https on
Step 5: Test the service!
Once you are done with the installation, configuration, commencement, and enabling the service, now you need to check the service functions. Is the Apache test web page on display. Are the directories exported with NFS accessible? Also, watch out for the network services that you have configured with the firewall. During the testing phase, confirm that the appropriate log files are generated and the log entries match the desired severity.
Commence the reviewing the /etc/rsyslog.conf file along with the page of service man.
Step 6: Is the service changed?
Make sure that the changes are made to the configuration file of the service during testing. When this is done then restart the service so that it can reread the file. Also, considering the future configuration file edits is important, the one you have made during the lifecycle of the service. Have a look at some of the examples that restart a service on SysV-based as well as system services:
# systemctl restart https
# service httpd restart
Conclusion
We hope that this detailed discussion regarding the deployment of Linux servers and tools has been insightful and informative for you. To know more about it, a few computer software courses can come in handy for you. However, you can establish a mental checklist to make sure that the steps are effectively deployed.
Remember — start and enable are not interchangeable terms, and they are separate actions. The same applies to stop and disable. Be aware of whether you are working with a systemd-based distribution or a distribution that uses SysV.
Have a look at the brief summary of the steps and tools:
1. Installation of rpm, yum, dnf
2. Configuration of vim, nano
3. Starting of systemctl or service
4. Persistency of systemctl or chkconfig
5. Testing of ping or standard client software
6. Reconfiguration of systemctl or service
If you liked the content our then do explore our repository at Knowledge Centre for similar reads. It is a place where you will find numerous value-adding, DIY tutorials to get you excited about emerging technologies.
