What is containerization?
Containerization is the act of packaging software code and all its required components such as libraries, frameworks, and other dependencies so that they are isolated in their own container.
It is now widely used in software development as an alternative or companion to virtualization. In containerization, the software code and all its dependencies are encapsulated so that the software can run smoothly and consistently on any infrastructure. Containerization technology is rapidly maturing and is giving rise to measurable benefits for developers and operations teams as well as software infrastructures.
The whole concept of containerization and process isolation is rather old, but when the open-source Docker Engine, the industry standard for containers with simple developer tools and a universal packaging approach, came into the picture in 2013, it rapidly accelerated the adoption of containerization technology. Gartner expected upwards of 50% of companies to make use of container technology by 2020. An IBM study even showed that 59% of container technology adopters ended up improving their application quality and reducing defects as a result of adopting the technology.
Containers are quite frequently called “lightweight,” which means that the containers share the machine’s operating system kernel and do not need the overhead of associating an operating system in every application.
They are smaller in capacity than a virtual machine and they need less start-up time. This makes it possible for a much larger number of containers to run on the same compute capacity as a single VM. This leads to greater server efficiencies and causes drops in server and licensing costs.
What is the purpose of containerization?
The whole purpose of containerization is to make it possible for developers to create and deploy applications faster and in a more secure manner. When traditional methods are used, code gets developed in a specific computing environment. When the code is transferred to a new location, bugs and errors will usually tend to surface.
Containerization gets rid of this issue by bundling the application code along with the related configuration files, libraries, and dependencies that are needed for it to run properly. This single package of software or “container” gets abstracted away from the host operating system. It then stands alone and is now portable, gaining the ability to run across any platform or cloud, without having any issues come up.
Essentially, containerization makes it possible for applications to be written once and run anywhere. The portability that containerization offers is vital in terms of the development process and vendor compatibility. It also provides several benefits like fault isolation, ease of management and security.
Can you containerize any application?
Technically, any application can be deployed in a container. There are several solutions that can be used to even containerize legacy applications. Some of these techniques include:
- Completely rewriting and redesigning the legacy application.
- Running an existing monolithic application within a single container.
- Augmenting and reshaping applications so that they can benefit from the new distributed architecture.
Whichever technique you choose, you first need to figure out whether the application you are considering is a good fit to be deployed in a container at all. You need to look closely at architecture, performance, and security.
What are the benefits of containerization?
Containerization brings several advantages to developers and development teams. Here are some of the biggest benefits of containerization:
Portability
A container will create an executable software package that will get abstracted away from the host operating system. This means that it is not dependent on or tied to the host operating system. Because of this, the containerized package of software has the ability to run in a uniform and consistent manner across any platform or cloud.
Agility
The open source Docker Engine for running containers kicked off the industry standard for containers that have simpler developer tools and have a universal packaging approach that works on Windows as well as Linux operating systems. The container ecosystem moved to engines that are managed by the Open Container Initiative (OCI). Software developers can keep on making use of agile or DevOps tools and processes to rapidly develop and enhance their applications.
Speed
As mentioned above, containers tend to be called lightweight, which means that they share the machine’s operating system (OS) kernel and are not stuck with the extra overhead. This leads to greater sever efficiencies and even lowers your server and licensing costs while speeding up start-times since there is no operating system that needs to be to booted.
Fault isolation
Every containerized application is isolated from the others and operates independently of the others. The fault of one container will not affect the continued operation of any other containers. Development teams will be able to identify and correct any technical issues that surface in one container without facing any downtime in any of the other containers. The container engine can even make use of the OS security isolation techniques like SELinux access control—to isolate the faults within containers.
Efficiency
Software that runs in containerized environments shares the machine’s OS kernel. Even the application layers within a container can be shared across containers. This means that containers are inherently smaller in capacity than virtuals machines (VMs) and need much less start-up time, which makes it possible for many more containers to run on the same compute capacity as one single virtual machine. This leads to higher server efficiencies and lower server and licensing costs.
Ease of management
Using a container orchestration platform will let you automate the installation, scaling, and management of containerized workloads and services. These platforms can even ease management tasks such as scaling containerized apps, rolling out new versions of apps, and offer monitoring, logging and debugging, among other functions. Kubernetes, which is the most widely used container orchestration system is an open source technology which automates Linux container functions originally. It works with several container engines like Docker, as well as any container system that conforms to the Open Container Initiative (OCI) standards for container image formats and runtimes.
Security
Isolating applications as containers prevents the invasion of malicious code from affecting other containers or the host system. You can also define security permissions to automatically block unwanted components from entering containers or even limit communications with unnecessary resources.
