352.2 LXC (weight: 6)

Tech Tutorial: 352.2 LXC (weight: 6) #

Introduction #

Linux Containers (LXC) are a lightweight virtualization technology. They run multiple, isolated Linux systems (containers) on a single Linux control host. LXC combines the kernel’s cgroups and support for isolated namespaces to provide an isolated environment for applications. Understanding LXC is essential for system administrators looking to improve the density and efficiency of their environments.

In this tutorial, we’ll cover the key knowledge areas required for managing LXC, including the creation, management, and maintenance of Linux containers.

Key Knowledge Areas #

  • LXC installation and configuration
  • Basic LXC administration
  • Networking for LXC
  • Storage for LXC
  • Cgroups

Utilities: #

  • lxc-create
  • lxc-start
  • lxc-stop
  • lxc-destroy
  • lxc-ls
  • lxc-info
  • lxc-attach
  • lxc-console

Step-by-Step Guide #

Setting Up Your Environment #

Before diving into the creation and management of containers, you must install LXC on your system. We’ll use Ubuntu as the host operating system for this tutorial.

sudo apt update
sudo apt install lxc lxc-templates

Verify Installation #

Check if LXC is installed properly by checking its version:

lxc --version

Creating a Container #

To create a new container using one of the available templates (e.g., Ubuntu):

sudo lxc-create -n mycontainer -t ubuntu

Here, -n specifies the name of the container, and -t specifies the template.

Starting the Container #

To start the container:

sudo lxc-start -n mycontainer

Listing Containers #

To list all containers:

sudo lxc-ls --fancy

This command provides detailed status of each container.

Container Information #

To get detailed information about a specific container:

sudo lxc-info -n mycontainer

Stopping a Container #

To stop a running container:

sudo lxc-stop -n mycontainer

Attaching to a Container #

To attach to a container’s console:

sudo lxc-attach -n mycontainer

Accessing Container Console #

To access the console of a container:

sudo lxc-console -n mycontainer

To exit the console, use the shortcut Ctrl+A Q.

Destroying a Container #

To completely remove a container:

sudo lxc-destroy -n mycontainer

Managing Container Networking #

LXC allows various networking setups. Here’s how to set up a bridged network which allows the container to connect through the host’s network:

  1. Install bridge utilities:

    sudo apt install bridge-utils

  2. Configure a bridge in /etc/network/interfaces:

    auto br0
iface br0 inet dhcp
    bridge_ports eth0

  3. Restart the network service:

    sudo service networking restart

  4. Configure the container’s network by editing the config at /var/lib/lxc/mycontainer/config:

    lxc.network.type = veth
lxc.network.link = br0
lxc.network.flags = up
lxc.network.hwaddr = 00:16:3e:xx:xx:xx

Managing Storage #

LXC supports various storage backends. To set up a separate storage for a container using LVM:

  1. Create a logical volume:

    sudo lvcreate -n mycontainer-root -L 10G vg0

  2. Attach the volume to the container by adding the following to the container’s config:

    lxc.rootfs = /dev/vg0/mycontainer-root
lxc.rootfs.backend = lvm

Conclusion #

In this tutorial, we’ve covered how to install, configure, and manage Linux Containers using LXC. By following the steps outlined, you can effectively create, manage, and destroy containers, set up networking, and manage storage for your containers. This setup enhances the deployment of isolated and secure application environments within a single host, leveraging the lightweight and fast nature of LXC.

Understanding and using LXC effectively can significantly optimize resource utilization and operational efficiency in many IT environments, particularly those requiring rapid provisioning and scalable solutions.