What are Containers?

In the traditional classical deployment scenario, we had hardware and an operating system for running multiple applications. If you want to run node.js, having certain dependencies, it will necessitate certain libraries and some specific kind of operating system. For example, in order to install MySQL, it requires some libraries, dependencies, and specific requirements of the operating system.

Likewise, if you run multiple software, each one of them will require its own library as well as dependency. It may even cause conflict because not necessarily each application will ask for the same libraries specific to some version; some may need a different version of the same library. Now the question is, how we will solve such an issue? Because eventually, you will end up with dependency matrix hell where you cannot upgrade or maintain this matrix hell.

To solve this dependency matrix hell for upgrading the software or the applications, we will utilize the containers. Containers build the application, ship the application, deploy, and scale these applications with ease and independently.

Containers vs. VMs

In order to learn about the container, it is recommended to first know how it varies from a traditional virtual machine (VM). In the case of traditional virtualization, a hypervisor is leveraged to virtualize physical hardware regardless of it being on-premises or in the cloud. For each virtual machine, there exists a guest of the operating system, a virtual blueprint of the hardware required by the OS to run, accompanied by an application and its connected libraries and dependencies.

The containers virtualize the operating system (typically Linux) rather than virtualizing the hidden hardware so that each particular container can include both the libraries and dependencies of the corresponding application. The containers are fast, portable, and lightweight due to the absence of the guest operating system.

Architecture of Container

Similar to the traditional ones, the container also has an Operating System and Hardware. On top of hardware, we have Container Engine such as Docker. The Container Engine software creates a container that packages the libraries and dependencies alongside as it will facilitate effortless movement of a container from one machine to another.

These libraries and dependencies come as a part of a package, which is nothing but a container. In the same way, we will have different containers, which can be easily moved across the Virtual Machines regardless of worrying about the underlying dependencies that may be required by the application to run because everything that is needed by an application to run is packaged as a container that you can move around.

Advantages of containers

• Installation: In the traditional scenario, installing an application was a laborious task because it will require you to run several commands for checking multiple dependencies. In fact, you may end up going into several dependencies of the software and conflicts that had to be resolved by you. To install the same application in the development environment, you will have to repeat the whole process back and forth, which is the only reason it is termed as a time-consuming task.
  Thus, to resolve such an issue, we require containers as everything is packaged. All you got to do is move it, followed by running a single command that will result in the automatic installation of all its dependencies and libraries deprived of conflicting with others.
• Software Dependencies: As we have already discussed, in the traditional model, software dependency was one such problematic issue, which now has been resolved by containers as it packages all the dependencies inside the container and isolate it. Since we can move containers from one system to another, they are easily manageable.
• Packaging: To resolve compatibility issues, the container packages the software so that it can be easily shipped without causing any fuss.
• Isolation: Containers also help in process isolation to track what is going on and to improve the security.
• Scalability: Containers are more scalable in contrast to the traditional development system. To scale the application horizontally, you can scale independent containers and utilize the load balancer or service, which will result in splitting the traffic. Since containers are more flexible, it makes sure applications are easily managed.

Container Management Platform

Container management platforms are well-defined as high-level tools that play a pre-eminent role in container orchestration. Container Management Platforms make use of fundamental container runtime systems. However, there exist some container management platforms that mix-match the accumulation of multiple container runtimes.

Kubernetes

Kubernetes, being designed and released by Google, refers to an open-source container management system. With Kubernetes, we can easily create a distributed cluster of hosted containers. Kubernetes offers robust container cluster orchestration tools, including health monitoring, deployment, failover, and auto-scaling.

Docker

Likewise, docker also provides you a group of utilities with which you can easily launch, orchestrate and manage the container's cluster. Since it has a huge demand, its container definition system is supported by several third-party container management systems such as Amazon ECS and Kubernetes.

Amazon ECS

Amazon Elastic Container Service is the only Amazon cloud-based service, which can easily manage the Docker containers inside a cluster. ECS comes up with one of the most powerful API that is tightly integrated with the rest of the Amazon cloud suite empowers a powerful workflow of DevOps.

Openshift

The Openshift container platform refers to an enterprise Red Hat Linux product. It can be understood as RedHat's cloud development Platform as a Service (PaaS). Openshift is one of those trusted enterprise cloud platforms that can merge with other Red Hat tools.

Use cases of containers

In the cloud environment, container plays an eminent role. Having said that, many companies are planning to replace the VMs with Containers being general-purpose compute platforms for their applications and workloads. Following are some relevant use case of containers:

• Microservices: Since containers are so small and lightweight, they are one of the best matches for microservice architectures where applications are constructed out of several loosely coupled and independently deployable smaller services.
• DevOps: The combination of microservices as architecture and containers as a platform is a common foundation for many teams that embrace DevOps, similar to how they are built, ship, and run the software.
• Hybrid, multi-cloud: The containers can run rationally at any platform, across laptops, on-premises, and cloud environments. They are a perfect basic architecture for hybrid cloud and multi-cloud schemes. Organizations determine themselves operating across a mix of multiple public clouds in sequence with their own data center.
• Application modernizing and migration: It is one of the preferred approaches to modernized applications that initiate by containerizing them so they can move them to the cloud.