What is containerisation?
Containerisation is an application’s code, and all the files and libraries required to function on any infrastructure are packaged together as part of the software deployment process. For instance, you needed to install a software package’s Windows version on a Windows computer. Containerisation enables you to build a single software package or container that is compatible with all hardware and operating systems.
Since containers share the machine’s kernel and do not need to associate an operating system with each program, they are frequently referred to as “lightweight” software. Numerous containers can run on the same amount of processing power as a single VM since containers are naturally smaller in capacity than VMs and start up faster. Increased server efficiency results in lower server and licensing costs as a result of this.
How does containerisation work?
A container is a special kind of virtual machine. The critical distinction is that typical hypervisors virtualise at the hardware layer, whereas container virtualisation occurs at the OS level. In other words, containers emulate the operating system to run an application rather than a hardware platform to run an operating system. Containers share some of the virtualization-related resources with the host.
In a containerised system consisting of the following levels, container images are the top layer.
The infrastructure hardware layer of the container model is called infrastructure. This term refers to the physical computer or bare-metal server that powers the containerised Application.
- Operating system
The operating system is the second layer of containerisation architecture. With on-premises PCs, Linux is a popular operating system for containerisation. In cloud computing, developers deploy containerised apps using cloud services like AWS EC2.
- Container engine
A container engine software, sometimes known as the container runtime, builds containers based on container images. It manages and provides the resources the Application requires by acting as an intermediary agent between the operating system and the containers. By maintaining their independence from the underlying infrastructure and one another, container engines, for instance, can handle many containers on the same operating system.
- Application and dependencies
Dependencies and Application, The top layer of the containerization architecture comprises the application code and other files it needs to operate, such as library dependencies and related configuration files. A thin guest operating system on top of the host operating system may also be in this layer.
Containerisation VS Virtualization
The distinction between containerisation (what containerisation software like Docker provides) and conventional server virtualisation can confuse the uninitiated (what hypervisors like HyperV and VMware ESXi enable). The distinction can be summed up as follows:
In server virtualisation, hardware is abstracted, and an operating system is executed. Running an app while outlining an operating system is what containerisation is all about. Containerisation is merely one “step “up” from server virtualisation; they both abstract away resources. In actuality, server virtualisation and containerisation may coexist. On top of a container engine set up inside a virtual machine, you can run containerised apps.
Types of containerisation
- Docker: Docker is a containerised open-sourced platform that mixes an app’s source code with the existing OS and its relevant libraries and dependencies. It enables the running of the appropriate code in any computing environment.
- LXC: An OS-based container that, if it includes a single Linux kernel acting as the host OS, enables an app to operate on numerous Linux computers virtually.
- CRI-O is a Container Runtime Interface (CRI) for the Kubernetes platform, which manages container clusters. It is a CRI to guarantee adherence to the OCI-compatible runtimes. As a result, this utility replaces Docker when used with Kubernetes.
- Rkt: The Rocket application-based container engine is employed to develop contemporary cloud-native apps. It operates CoreOS, which uses security enhancements that older Docker versions were known to feature. It functions best when combined with the necessary technologies or as specific components of a Docker-based system.
Benefits of Containerization
Software developers and development teams can gain much from containerisation, from increased agility and portability to better cost management.
- Portability
An executable software package created by an application container is separated from the host OS. As a result, it is not reliant on or bound to the host OS, which makes it portable and enables it to function reliably and evenly on any platform or cloud. The OS consolidation techniques developers use also prevent irregularities like integration that aim to block the program’s functionality.
- Agility
With its straightforward development tools and universal packaging strategy that operates on both Linux and Windows operating systems, the open-source Docker Engine for running containers helped establish the industry standard for containers. The Open Container Initiative is now managing the container ecosystem’s engines (OCI). For applications’ rapid
development and improvement, software engineers might keep employing agile or DevOps technologies and techniques.
- Speed
Since containers share the machine’s operating system (OS) kernel, they are said to be “lightweight” since this additional overhead does not burden them. In addition to increasing server efficiency, this also lowers server and licensing costs while shortening startup times because an operating system is not required.
- Scalability
The technology used in application containers allows significant scalability. Users can use a service-oriented application design to enable resources in an application container to enable it to accommodate increasing demands. In contrast, a developer can include more containers in distributed machines. A container environment allows it to quickly add new features, functions, and upgrades without disrupting the original applications. Containers thereby provide app scaling with little resource consumption.
- Efficiency
Developers can share the app layers between containers since the software executes in containerised environments and communicates the OS kernel with the host computer. Compared to virtual computers, containers naturally have reduced capacity. Developers can run multiple containers using one virtual machine’s computational capability. This boosts server efficiency and lowers related server and licensing expenses.
