Install LXC (Linux Containers) in RHEL, Rocky & AlmaLinux

LXC (Linux Containers) is an operating system-level virtualization method that allows you to run multiple isolated Linux systems (containers) on a single host. It provides a lightweight and efficient alternative to traditional virtualization technologies like VMware or VirtualBox. In this guide, we will walk through installing LXC on RHEL, Rocky Linux, and AlmaLinux.

Prerequisites

Before proceeding with the installation, ensure that you have the following prerequisites

• A supported version of RHEL, Rocky Linux, or AlmaLinux

• Sudo or root access to the system

• An internet connection

• At least 2GB RAM and 10GB free disk space

Step 1 Update the System

Start by updating the system packages to the latest versions. Open a terminal or SSH session and execute the following commands

sudo yum update -y

Step 2 Install EPEL Repository

LXC packages are available in the EPEL (Extra Packages for Enterprise Linux) repository. Install EPEL first

sudo yum install epel-release -y

Step 3 Install LXC Packages

Install the LXC packages using the appropriate package manager based on your distribution

For RHEL and Rocky Linux

sudo yum install lxc lxc-templates lxc-extra -y

Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package lxc.x86_64 0:3.2.1-4.el7 will be installed
---> Package lxc-extra.x86_64 0:3.2.1-4.el7 will be installed
---> Package lxc-templates.noarch 0:3.2.1-4.el7 will be installed

Transaction Summary
================================================================================
Install  3 Packages (+1 Dependent package)

Total download size: 2.7 M
Installed size: 10 M
Is this ok [y/d/N]: y

Installed:
  lxc.x86_64 0:3.2.1-4.el7
  lxc-extra.x86_64 0:3.2.1-4.el7  
  lxc-templates.noarch 0:3.2.1-4.el7

Complete!

For AlmaLinux

sudo dnf install lxc lxc-templates lxc-extra -y

Dependencies resolved.
================================================================================
 Package                  Arch         Version               Repository   Size
================================================================================
Installing:
 lxc                      x86_64       3.2.1-7.fc35          updates     853 k
 lxc-extra                x86_64       3.2.1-7.fc35          updates     1.3 M
 lxc-templates            noarch       3.2.1-7.fc35          updates      63 k

Transaction Summary
================================================================================
Install  3 Packages

Total download size: 2.2 M
Installed size: 9.7 M

Installed:
  lxc-templates-3.2.1-7.fc35.noarch      lxc-3.2.1-7.fc35.x86_64     
  lxc-extra-3.2.1-7.fc35.x86_64         

Complete!

Step 4 Configure LXC Network Bridge

LXC uses a bridge interface to provide networking capabilities to containers. Configure the default bridge by creating a configuration file

sudo vi /etc/lxc/default.conf

Add the following network configuration

lxc.net.0.type = veth
lxc.net.0.link = lxcbr0
lxc.net.0.flags = up
lxc.net.0.hwaddr = 00:16:3e:xx:xx:xx

Step 5 Start and Enable LXC Services

Start the LXC services and enable them to start automatically at boot

sudo systemctl start lxc.service
sudo systemctl enable lxc.service

Created symlink /etc/systemd/system/multi-user.target.wants/lxc.service ? /usr/lib/systemd/system/lxc.service.

Step 6 Create and Test a Container

Verify the LXC installation by creating a test container

sudo lxc-create -t download -n mycontainer -- -d centos -r 8 -a amd64

Setting up the GPG keyring
Downloading the image index
Downloading the rootfs
Downloading the metadata
The image cache is now ready
Unpacking the rootfs

---
You just created a CentOS container (release: 8, arch: amd64, variant: default)

For security reason, container images ship without user accounts
and without a root password.

Use lxc-attach or chroot directly into the rootfs to set a root password
or create user accounts.

Start the container and check its status

sudo lxc-start -n mycontainer -d
sudo lxc-info -n mycontainer

Name:           mycontainer
State:          RUNNING
PID:            12345
IP:             10.0.3.100
CPU usage:      5.0%
Memory usage:   256 MB (50%)

Common LXC Commands

Conclusion

You have successfully installed LXC on RHEL, Rocky Linux, and AlmaLinux. LXC provides an efficient containerization solution with lower overhead than traditional virtualization. With these containers, you can now isolate applications, test different configurations, and optimize resource utilization on your system.