Table of contents
1.
Introduction
2.
What are Containers?
3.
What are LXC or Linux Containers?
4.
Advantages of Linux Containers
5.
Disadvantages of Linux Containers
6.
Use Cases for Linux Containers
7.
Working with Linux containers(LXC)
7.1.
cmd
7.2.
cmd
7.3.
cmd
7.4.
cmd
7.5.
cmd
7.6.
cmd
8.
Best practices for using Linux containers(LXC)
9.
Frequently Asked Questions
9.1.
What are the differences, between containers and virtual machines (VMs)?
9.2.
What benefits do containers provide?
9.3.
Can you explain what a container image is?
10.
Conclusion
Last Updated: Mar 27, 2024
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Linux Containers

Author Shiva
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Introduction

Linux containers have become a game changer, in the changing world of software development and deployment. These portable and lightweight environments offer a way to package, distribute and run applications seamlessly on platforms. They provide a flexible alternative, to traditional virtualization methods.

Linux Containers

In this article we will look at Linux containers exploring their advantages and disadvantages. We will also discuss scenarios where they can be effectively used. We will also see a collection of commands for working with them.

What are Containers?

Containers are a tool that allows you to run an application along, with all its necessary components in one lightweight package. This approach offers benefits, such as portability, scalability, security and agility for your applications.

When we refer to containers we mean a set of data containing everything needed to operate an application. This includes the applications code itself with libraries, dependencies, configuration files and any additional system utilities required. The container seamlessly integrates all these elements as, per the applications requirements.

The container platform builds the base image from which the sample application or microservice is derived. Then deploys that image to the container platform for use.

What is an image in containers? It is an executable file. That is static and unalterable and may run an isolated process on IT infrastructure. The image consists of the platform settings needed for the software to execute on a containerisation platform. Which include system libraries, system tools, and other platform parameters.

Virtualization vs Containers

What are LXC or Linux Containers?

Linux container or LXC is a lightweight, stand-alone, and executable package.  That includes everything needed to run a piece of software, including the code, runtime, system tools, and libraries. Think of it as a miniaturised, isolated environment within your Linux operating system. It is designed to run a specific application without interfering with the host system or other containers. 

LXC often gets confused with Docker. Whereas both are totally different. One application can be contained in one container with the use of Docker. So you can run numerous independent applications on a server. LXC is made to isolate ONE operating system in ONE container. So you can run various independent operating systems on a server.

You might have also heard about Linux Daemon or LXD with LXC. Built on the foundation of LXC, LXD is a flexible system container and virtual machine manager. It improves your entire container experience while also making control and maintenance easier. LXD employs an image-centric methodology. It has a large collection of images created specifically for different Linux distributions. Having a simple command-line tool at your disposal makes managing instances simple.

Advantages of Linux Containers

  • Containers offer a level of protection, for processes and file systems. Thus, ensuring that applications can operate independently without interfering with one another.
     
  • Containers are able to run across environments. Whether its on a developers laptop or a production server thanks, to their self contained nature.
     
  • Containerized applications share the host operating system kernel resulting in overhead and efficient use of resources.
     
  • Containers can be quickly started and stopped. Enabling application deployment and scalability.
     
  • Container images have built in versioning capabilities. Thus, making it easy to roll back changes or implement updates.

Disadvantages of Linux Containers

  • Containers share the host OS kernel. Due to this, at the kernel level it could affect all the containers on that host. To address this it's crucial to implement security measures such as container isolation and regular updates.
     
  • There is a learning curve involved for newcomers to containers. It takes time to understand concepts like images, runtimes and orchestrators.
     
  • Without resource management practices in place, containers can consume CPU and memory resources. This can lead to performance issues. Administrators must configure resource limits. Also implement monitoring mechanisms to prevent contention.
     
  • Containers are typically designed for short term use. Not intended for long term data storage. Handling data within containers requires volumes or persistent storage solutions.
     
  • Networking configurations for containers can be complex. especially in multi-container and multi-host environments. Container orchestration platforms help manage networking. But it still requires expertise to set up correctly.
     
  • Containers are typically designed for headless, command-line-based applications. Running graphical applications within containers can be challenging and may require workarounds.

Use Cases for Linux Containers

  • Containers offer a solution, for constructing applications based on microservices. Each microservice can operate within its container.  This simplifies the development, testing and deployment processes.
     
  • Containers streamline the CI/CD pipeline by ensuring packaging of applications throughout their lifecycle.
     
  • Containers make it easier to move applications across cloud providers and on premises infrastructure promoting neutrality in vendor choices.
     
  • Developers can create containerized development environments that closely resemble the production environment reducing issues related to "it works on my machine" scenarios.
     
  • Certain serverless platforms, like AWS Lambda and Azure Functions use containers to run functions. This allows developers to package and deploy code in containers without having to manage the underlying infrastructure.

Working with Linux containers(LXC)

To use LXC containers, you'll need a Linux computer with LXC tools installed. You can check if you have them by typing this:

  • cmd

cmd

lxc-info

 

If it's not there, you'll have to install LXC tools. On Ubuntu and similar systems, you can do it with this command:

  • cmd

cmd

sudo apt-get install lxc

 

Once LXC is set up, you can make a new container using the `lxc-create` command. For instance, to make a container based on Ubuntu, you can do this:

  • cmd

cmd

lxc-create -t ubuntu -n my-container

 

When you create a Linux container you can initiate it by using the command `lxc-start`. This will activate the container. Launch its startup system, which initializes all the services within it. To begin a container named "my-container " you can execute the command;

  • cmd

cmd

lxc-start -n my-container

 

Once you've completed that step you can use the `lxc-attach` command to access the console of the Linux container. This will provide you with a command prompt, within the container allowing you to execute commands and perform tasks on the system to a Linux computer. For example if you want to enter a container called "my-container " simply use the command;

  • cmd

cmd

lxc-attach -n my-container

 

This links you to a command prompt inside the Linux container, where you can run commands and manage the container like you would with any other Linux system. To stop the container, use the `lxc-stop` command:

  • cmd

cmd

lxc-stop -n my-container

 

These were some basic steps for managing LXC containers. It's essential to explore the documentation and experiment, with options and advanced functionalities to gain an understanding of how LXC operates.

Best practices for using Linux containers(LXC)

Here are some helpful tips to effectively use Linux containers (LXC);

  • Ensure that you're using the version of LXC to take advantage of its features and benefit from updates and bug fixes.
     
  • It's advisable to create containers, for each task or application you intend to use. This approach helps prevent any interference or conflicts, between them.
     
  • Use Git to save your container configuration. This way you can easily track your actions. Revert any changes if necessary.
     
  • Docker or Kubernetes can be employed as management tools for handling containers. They act as supervisors streamlining their functionality and usage.
     
  • Manage your container's performance. Ensure they have all the necessary resources for smooth operation. If assistance is required in identifying and resolving issues it's crucial to monitor them.
     
  • Ensure that your containers maintain isolation from one another. Also they do not interfere with your computers system or network connections. This approach guarantees an environment while preventing network complications.
     
  • Each container should only utilize the amount of resources it requires. Thus, preventing one resource heavy container from causing disruptions across the entire system.
     
  • Regularly update and secure everything within your containers. Thus, including software components and dependencies as this helps maintain an environment by keeping actors at bay while ensuring access to up, to date software versions.

Frequently Asked Questions

What are the differences, between containers and virtual machines (VMs)?

Containers are more efficient than VMs because they share the host operating system whereas VMs have their operating system that consumes resources.

What benefits do containers provide?

Containers offer advantages such as portability, scalability and rapid deployment. They make application management simpler. Ensure consistency across environments.

Can you explain what a container image is?

A container image is, like a snapshot of an application and its dependencies. It serves as a read blueprint used to create containers.

Conclusion

Linux containers are a game changing technology that makes it easier to deploy applications optimize resource usage and improve software development methods. Containers package. Their requirements together ensuring uniformity, across environments ranging from development, to production stages.

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