Docker virtualization has taken the world by storm. It is one of the most robust technologies ever incorporated in cloud. Docker cloud computing has become a norm in modern day virtualization. At the most rudimentary level, docker is but a platform as a service that allows users to create containers. Different platforms will have different resources and libraries but are aware of each other's presence in the system. The containers can interact with one another through various channels.
Unlike virtual machines that work on the top of the base machine using hypervisor, docker runs VMs within an operating system. Thus, using docker virtualization, you can run an operating system within another operating system. However, the biggest disadvantage is that both the OS must be of the same type or have similar source code. Thus, you might not be able to run Windows over a Linux or Linux over Windows OS because there is no Linux-Windows kernel support. Thus, you can run CentOS container within an RHEL system or over Ubuntu. But you cannot run RHEL container on Windows because inter kernel support is unavailable.
Docker is the New Craze in Virtualization and Cloud Computing. Why are People so Excited About it?
Docker engages what is known as the OS-level virtualization. It is simplest and yet of extreme help. From technical standpoint, virtualization is implemented in three different ways:
Such type of virtualization makes use of a hypervisor that oversees working of all virtual machines in the system. The hypervisor keeps two VMs completely unaware of one another. To do so, it allocates memory space from the underlying resource to the virtual machines as and when needs arise. Because a lot of calculations is done by the hypervisor, the hypervisor eats small but not negligent portion of the CPU.
Such type of virtualization works just like full virtualization except that the VMs are now aware of each other presence in the system. The VMs work not as separate machines but as one cohesive unit. Each OS (VM) is aware of the demands other operating systems are making so the hypervisor has little work to do, when compared to the hypervisor in full virtualization.
This is where docker cloud hosting comes into existence. In OS-level virtualization all OSs are completely aware of all the other operating systems because the host is an OS itself. It does not need a hypervisor as the host OS will perform necessary functions. Guests or the OS that are running within the host are called containers.
Docker makes use of the OS-level virtualization to create container and assigns the functions to the root OS. Such virtualization is also called homogenous environment because all the operating systems need to be the same.
Undoubtedly, Docker is the new craze in the virtualization and the Cloud computing, and people are very much excited about it. The most prominent reason I see is that it is an ultra-lightweight containerization app filled with potential. Others are - it's fast, easy-to-use and developer centric.
The main objective of Docker is to make it easy to package and ship code. Developers are always in search of tools that abstract away much of the details of that process. They only want to see their code working, which causes all kind of clashes with System Administrators when the code is shipped around and turns out, susceptible to work in the developer's environment only.
Docker comes in the rescue, and turns to work around by making your code as portable as possible. Further, it makes that portability simple and easy to use.
Above mentioned are some of the reasons why people are so excited about Docker.