In today's digital age, keeping systems updated and secure is a top priority for every IT professional. CentOS 7, a popular server distribution of Linux, offers various tools and methods to ensure security through automatic updates. This article provides a detailed guide on configuring these updates, focusing on security patches for critical system components and applications.

Prerequisites

Before configuring automatic updates, ensure you have administrative rights (root access) on your CentOS 7 system and an active internet connection.

Installation and Configuration of yum-cron

CentOS 7 uses yum as its package manager, which allows for the installation, update, and removal of software packages. To automate updates, we will use the yum-cron service.

1. Installing yum-cron

   Open a terminal and run the following command to install yum-cron:

   sudo yum install yum-cron
   

2. Configuring yum-cron for Automatic Updates

   After installing yum-cron, you need to edit its configuration file located at /etc/yum/yum-cron.conf. Use any text editor, such as nano, for editing:

   sudo nano /etc/yum/yum-cron.conf
   

   In the configuration file, pay attention to the following directives:

   • update_cmd: This directive specifies the type of updates yum-cron will perform. For security updates, set the value to security.
   • apply_updates: By setting this directive to yes, you enable the automatic application of security updates.

   Example configuration for security updates:

   update_cmd = security
   apply_updates = yes
   

3. Enabling and Starting the yum-cron Service

   After completing the configuration, you need to enable and start the yum-cron service:

   sudo systemctl enable yum-cron
   sudo systemctl start yum-cron
   

   To verify that the service is running, you can use:

   sudo systemctl status yum-cron
   

Security and Further Steps

Although automatic updates can significantly enhance system security by ensuring quick application of security patches, it's also essential to perform regular audit checks and system backups. This helps prevent negative impacts in case of incompatible updates or other undesired side effects.

Automatic updates on CentOS 7 using yum-cron offer an efficient way to keep the system secure and up-to-date. With this guide, you are equipped to set up your system to automatically detect and apply security patches for critical components and applications, thereby increasing the overall resilience of the system against cyber threats.