What is a configuration file?

Published November 28, 2022•5-minute read
Copy URL

Jump to section

OverviewConfiguration files explainedWhat is an API config?Why do configuration files matter?How to manage configuration files with Linux

A configuration file (config file) is code on your computer that selects various features and settings. It can determine parameters, preferences, and alternative options in the many realms of your IT environment. Despite the complexity of operating systems that digital devices contain, config files allow an operator to simplify, to choose specific preferences for a particular user experience.

In this article, we are asking (and answering) questions like: What are configuration files? What’s their functionality? And, how can they work to your advantage in aLinux® environment? 

Download the Podman ebook to learn more about the next-generation container engine with easy-to-follow examples and step-by-step instructions to deploy a complete containerized web service. 

 

Download the Podman e-book

Configuration files explained

A configuration file is known by many names. More specifically, by a filename or file extension that includes but is not limited to conf., cfg., cf., and so on. A configuration file’s function can vary even more than its name. There are thousands of different config files, hard at work, on your own personal computer. In its simplest form, config files are a form of user interface. Instead of clicking buttons to make things happen, you edit text.

It’s easy to think of a config file as a high-tech customization tool. Config files allow an operator to determinestorage paths, select which plug-ins to include (and not include), and even which colors and images are allowed for backgrounds and interfaces. These are called your configuration options. Configuration options can range from simple to specific. These options vary and should be used intentionally.

Config files store data for applications that enable users to interact with thoseapplications in a specific and purposeful way. For example, if you’re trying to configure a SQL (Structured Query Language) server, you may use a configuration file to determine which IP addresses can access the database. 

Config files act as a bridge between the user, a program, or an aspect of the operating system. It allows you to get into a piece of software and get a sense of what’s going on behind the scenes. 

Run containers on Linux with Podman 

How to manage config files 

Luckily, config files are as flexible as they are functional. They can be managed with a variety of different tools, whether you want to edit, change, or even create a config file from scratch.

Before you begin working with config files, you’ll need to identify which file format you’ll be working in:YAML, INI, JSON, XML, TOML, etc. Each file format works a little bit differently, so you’ll need to be aware of their particularities and permissions. For example, when working with JavaScript, many programmers prefer to write configuration files in JSON.

Configuration files are in plain text formats that make it possible to edit by hand using a text editor. In some instances, there are applications that allow the user to modify the configuration file with graphical interfaces.

In the instance of a change, you’ll want to establish a system that allows you to comment to communicate changes within each config file. This will keep track of ongoing activity and alterations to the file. Make sure to leave comments that will be clear to others. Version control will be another essential facet of the config file to roll back changes when working through a series of changes like storage paths, ports, or time-outs. Templates can also be helpful when making certain changes over time.

Testing will be imperative when creating a config file and changing its functionality. The testing and launch should be treated as critical in order to reach the desired result and function. 

Get the beginner's guide to config files 

Red Hat resources

What is an API config?

An API (application programming interface) acts as the middleman software interface so that two different technologies can talk to one another. A configuration API acts as a common ground for data to be stored and computed between interfaces. This configuration file format can vary from foundational to more complex. Make sure you understand the function of your specific API so that you can store data correctly and get the desired communication between interfaces. 

What is the Kubernetes API?

Why do configuration files matter?

Config files are a pillar of your computer. While config files can be very simple structures, they simplify extremely complex interfaces. One config file may not seem like it makes a big difference, but when that config file determines thousands of features on your device, you’ll quickly realize it’s necessary. If one minor config file goes awry, you may not notice. But if they all stopped working one day, your apps would look a lot different and you’d expect some serious technical difficulties ahead. 

A major benefit is reproducibility. It makes troubleshooting a lot easier when you have just one file governing a system. Now, when you move to a different, system, all it takes is migrating a copy of your config files to replicate your settings.

Why you should keep up with config files

The purpose of config files is to make a complex system, just the opposite: simple. Config files allow you to organize, manage, and customize the applications that communicate with your operating system. These files allow operators to control extensive and often complicated systems that decide how your device functions. Without config files, there would be a lot of gaps in your operating system and your experience with technology would look very different. 

What can happen if you don’t manage your config files

Managing config files can be intimidating, but what’s even more intimidating is fixing a mistake after mismanagement. It’s critical to manage your config files properly in order to keep them running like a well-oiled machine. This is one of the main reasons why it’s so important to keep track of changes within each config file. Each change may need to be referred to, reconciled, or built upon at a later date. Having the correct config file parameters at the beginning will help, but continuous management is the key to running your applications successfully. 

One of the biggest challenges is knowing the options available to you. A config file may not make all of its flexibility and options known to the user. There are a finite number of buttons available on a graphical interface, but in a config file, not all of the options are written out. For instance, it will present the options "yes" and "no", but there may be another option available that isn’t visible on the surface. At first glance, it can be difficult to understand the entire scope. The more you manage and interact with your config files, the more aware you will be of your options.

Worst case scenario: things break. If you don’t know the previous settings by heart, you’re left with documentation and trial and error to get back to where you were. If the config files are completely wiped, without a backup, your computer may not run at all. This is why it is imperative that you save a backup of a config file before you make changes.

How to manage configuration files with Linux

Linux configuration files make up a large portion of Linux operating systems. There are numerous config files for eachLinux distribution. While each configuration file functions differently, they all allow you to customize your computer. Linux relies on files that you can use to change settings in a way that is understandable for the user. 

What is Linux? 

Read more about Linux containers 

How Red Hat manages config files with Linux

OpenShift is managed with YAML config files. They act as an interface for Linux, as well asKubernetes and other systems. 

It helps to think of the tabs and colons as their way of communicating. The different combinations of symbols define what the file looks like and is your tool to manipulate the system. If you want to configure something with the YAML file, there’s going to be one combination of terms that will unlock the change in the system. Knowing which "vocabulary" to use is key. Unlike the human language, where we have various vocabularies to help us get our point across, the computer needs one combination of symbols to understand the config files.

Why choose Red Hat for Kubernetes 

Explore open source solutions 

Hub

The official Red Hat blog

Get the latest information about our ecosystem of customers, partners, and communities.

All Red Hat product trials

Our no-cost product trials help you gain hands-on experience, prepare for a certification, or assess if a product is right for your organization.

Keep reading

Why run Linux on AWS?

For organizations using Amazon Web Services (AWS), Linux shortens time to market, reduces complexity, provides on-demand scalability, and lowers costs.

What is high availability?

High availability determines if a system is meeting its operational performance level, is available almost 100% of the time, and is performant for an established time period.

What is ERP?

Enterprise resource planning (ERP) unifies the massive amounts of data within an organization, and enables information flow between different teams.

Linux resources

Related articles