Understanding Containerization and its Benefits

In conventional software development, when a code developed in one computing environment is deployed to another environment, such as from desktop to a virtual machine or from Linux to Windows OS, it often runs with bugs and errors. Software developers address this hitch by running the software in “containers” in the cloud. Containerization has become a popular trend in software development as a companion or alternative to virtualization and allows developers to create and deploy applications faster and more securely.

What is Containerization?

Containerization encompasses bundling an application together with everything that it needs to run- configuration files, binaries, libraries, and dependencies, in an efficient and bug-free manner across diverse computing environments. In other words, it allows applications to run in isolated user spaces, called containers, using the same shared operating system. All that an application requires to run is encapsulated and isolated in its container. The container is abstracted away from the host OS, with only limited access to underlying resources, and thus the containerized application can be run across multiple infrastructures, without having to refactor it for each environment.

This is because containers share the same OS kernel and they do not require the overhead of setting up an operating system for each application. The two highly popular containerization ecosystems are Docker and Kubernetes.

Containers vs Virtual Machines

A lot of comparison goes around between Containers and Virtual Machines since both allow different types of software to be run in a computed environment. To break down the differences, containers are an abstraction of the application layer that packages code and dependencies together, whereas virtual machines are an abstraction of the hardware layer which means that each VM simulates a physical machine that can run the software.

Although each container runs isolated processes, they all share the same operating system. Virtual Machine technology utilizes one physical server to run the many server equivalents, each of which is called a virtual machine. So while many VMs run on a single physical machine, each VM has its copy of an OS, applications & necessary binaries, libraries, and dependencies.

Containers are naturally smaller in capacity than a VM and require less start-up time, can handle more applications, and require fewer VMs and operating systems. This drives higher server efficiencies and eventually cuts down the server and licensing costs.

Benefits of Containerization

Simply put, containerization lets applications be written once and run anywhere. This portability is significant in terms of the software development process and vendor compatibility. It also provides other key benefits such as fault isolation, ease of management, and security, to name a few. Let’s take a brief look at the benefits of containerization.

1. Agility

Containers are comparatively simpler to set up than Virtual Machines and work on both Linux and Windows operating systems. The essential developer tools are universal, simple, and user-friendly, which allows for rapid application development and enhancement, packaging and deployment of containerized applications across operating systems. DevOps engineers and teams leverage containerization technologies to speed up their workflows. The container ecosystem has shifted to engines managed by the Open Container Initiative (OCI).

2. Fault Isolation

Each containerized application is isolated and operates independently of others. The failure of one container does not affect the others sharing the OS kernel, thanks to the user space isolation between them. Microservices-based applications are greatly benefitted through this, in which diverse multiple components support a larger program. The development teams can identify and fix any technical hitches within one container without causing any downtime in others. Also, the container engine can utilize any OS security isolation techniques such as SELinux access control- to isolate faults within containers.

3. Easier Management

A container orchestration platform automates the installation, scaling, and management of containerized apps and services. It eases various tasks such as scaling containerized apps, rolling out app updates, providing monitoring, logging, and debugging among other updates. Using Kubernetes, which is perhaps the most popular container orchestration available, it’s possible to automate rollouts and rollbacks, orchestrate storage systems, perform load balancing and restart any failing containers. Kubernetes is compatible with many container engines, such as Docker and Open Container Initiative (OCI).

4. Portability

A container forms an executable package of software that is abstracted away from the host OS, and thus is portable and can run uniformly and consistently across platforms or the cloud. As mentioned earlier, they follow a “write once, run anywhere” process. It can be written for one host environment and then ported and deployed to another, as long as the new host supports the container technologies and OSes in question. Linux containers capture a major share of all deployed containers and can be ported across diverse Linux-based operating systems. Speaking of Windows, Linux containers can be reliably run inside a Linux virtual machine or through Hyper-V isolation.

5. Boon to DevOps

Virtual machine systems consist of a complete OS packed with drivers, binaries or libraries, and the actual application. Each operating system sits on top of a hypervisor that controls the physical server hardware. The issue with this approach is that it wastes server memory. Containerization, on the other hand, represents a much more streamlined approach to DevOps. It reduces wasted resources because each container only holds the application and related binaries or libraries.

6. Security

The isolation of applications as containers puts a stop to the malicious code invading or affecting other containers or the host OS. Moreover, security requests can be defined to automatically block redundant components from entering containers or limit communications with unwanted resources.

7. Scalability

By allowing more containers in the environment without the requirement for additional servers, containerization boosts scalability around 10 to 100 times that of traditional VM environments.

Types of Apps and Services that are commonly Containerized

A container can support many types of applications that were earlier virtualized or used to run natively on a machine. Simultaneously, various paradigms are there that suits containerization, such as-

1. Microservices

A microservice architecture can be efficiently configured as a set of containers operating in tandem and spun-up and decommissioned as needed.

2. Databases

Database shards can be containerized and each app is offered its dedicated database instead of needing to connect all of them to a monolithic database.

3. Web servers

Spinning up a web server within a container requires only a few command-line inputs to get started, and moreover, it avoids the need to run the server directly on the host.

4. Containers within Virtual Machines

Containers may be run within VMs, generally to maximize hardware utilization, speak to specific services in the VM, and/or scale up the security level.

Conclusion

Containerization has evolved in software application development and will likely become a new norm in this field. In the coming years, its adoption will also take a major boost in both magnitude and speed. Big IT players like Google and IBM are investing heavily in containerization. Although it seems an expensive deal, the associated costs are expected to drop significantly as containerization environments develop further and get more mature.