Containerization has become a serious trend in the software development world, especially as an alternative to virtualization. In fact, containers can easily be considered the future of application hosting and development. COntainers allow developers, DevOps teams, and system administrators to build and maintain their applications quickly, efficiently, and securely. The same goes for testing and deployment.
Additionally, the tools designed for containerization also provide quick solutions for simple web applications.
In this article, we’re going to discuss containerization, how containers work, and what the benefits are.
What Exactly is Containerization?
Containerization is most commonly defined as a form of operating system virtualization.
Operating system virtualization enables the use of software to allow your system hardware to run multiple applications that require different operating systems simultaneously—on one computer system. The operating systems within this one computer system don’t interfere with one another, nor do the various applications being run on them.
When we talk about containerization, we’re still talking about running the various applications with different operating systems using one shared operating system (OS). However, these applications are run in isolated user spaces referred to as containers.
You can think of containers as fully loaded and portable computing environments. They have everything an application needs to run, including binaries, libraries, configuration files, and dependencies.
Each container by themselves is also detached from their OS host, making them incredibly lightweight virtual machines (VMs).
Because of the independent nature of containerization, any containerized applications can be run using virtually any type of infrastructure. That would include virtual machines, on-premise hardware, and even in the cloud—all without having to reconfigure each environment.
Additionally, there’s less overhead when it comes to the startup of containerized applications. This is also attributed to their independent nature. More importantly, there’s no need to set up separate guest operating systems per application since they all share the same OS core, creating a more efficient working environment.
This makes containerization most suitable for packaging individual microservices that make up all of today’s modern applications.
How Do Containers Work?
So, we know that a container is essentially a standardized unit of software that’s abstracted from the main operating system. Each container contains the code and all the dependencies that can be run and transferred without having to alter the environment. Therefore, containers will always provide the same stable environment containing everything a software application needs to run.
But how exactly do they work?
For starters, these standardized units of software are all executable packages running on a hosted OS. An OS host can support containers well into the thousands, concurrently.
With this kind of setup, the containers can run on very minimal resource-isolated processes that other containers or networks can’t access.
It’s actually much easier to think of a containerized application as part of a multi-layered cake. More specifically, the icing.
First, you have the bottom layer. Here is where the hardware infrastructure including the CPU, disk storage, and network interfaces exist. Working your way up to the second later, there’s the host operating system and its core. The core acts as a bridge between the OS software and the underlying system’s hardware.
Next, you have the container “engine” and a guest bare-bones operating system. This secondary system basically sits on top of the actual host OS and is a particular feature in teams of the containerization technology that’s being used.
Lastly—or at the very top—are the binaries and libraries (also referred to as bins/libs). These apply to each application and run within their isolated user spaces—or, containers.
In essence, containerization works by bundling applications together with all of their related configuration files, binaries, libraries, and dependencies that allow them to run efficiently and bug-free across the various computing environments.
What Are the Benefits of Containerized Applications?
Containerization offers a significant amount of benefits for software developers and development teams alike.
Those benefits include:
As previously mentioned, a container is basically an executable package of software that’s independently run from its host OS. Therefore, containerized applications are extremely portable as they’re able to run without incident across any platform or cloud.
Containers are most known for the fact that they’re lightweight. In other words, while they share the virtual machine’s operating system core, they aren’t tied down by its excessive overhead.
That means containers not only drive efficiency within the server by speeding up start times, they also reduce licensing costs.
Each containerized application is isolated and therefore operates independently of the other containerized applications. That means the failure of one container will have little to no effect on the continuing operation (although as the systems are connected and information is passed on it will not be without any impact) of any other containers running on the same OS.
This makes it much easier for development teams to identify and correct any technical issues within one container without worrying about any downtime for other containers.
When you’re running software within containerized environments that are sharing the VM’s OS core, the application layers can be shared across other containers. Therefore, the containers require less start-up time and take up less computing space, which drives efficiency.
When containers are built, they’re designed to include an automated installation process as well as automated management tasks, workloads, and services. This makes scaling, rolling out new versions of applications, monitoring, logging, debugging, and other functions much easier.
When you have isolated applications as containers it intrinsically prevents malicious code from entering the system and affecting other containers and even the host system. Additionally, developers can define security permissions to block any unwanted components from entering their containers or limit communications with unnecessary resources automatically.
Containers have quickly become the staple building blocks for modern software application development. Containerization makes it much simpler and quicker to build and deploy apps as well as manage and debug them, and it’s all thanks to the fact that they’re designed to work independently from each other while sharing the same hosted OS.