The first and foremost driver for Docker-enabled containerization is to competently and completely overcome the widely expressed limitations of the virtualization paradigm. Actually, we have been working on the proven virtualization techniques and tools for quite a long time now in order to realize the much-demanded software portability. That is, with the goal of decimating the inhibiting dependency between software and hardware, there have been several initiatives that incidentally include the matured and stabilized virtualization paradigm. Virtualization is a kind of beneficial abstraction, which is accomplished through the incorporation of an additional layer of indirection between hardware resources and software components. Through this freshly introduced abstraction layer (hypervisor or virtual machine monitor (VMM)), any kind of software application can run on any underlying hardware without any hitch or hurdle. In short, the software portability is being achieved through this middleware layer. However, the much-published portability target is not fully met even by the virtualization technique. The hypervisor software and different data encapsulation formats from different vendors come in the way of ensuring the much-needed application portability. Furthermore, the distribution, version, edition, and patching differences of operating systems and application workloads hinder the smooth portability of workloads across systems and locations.

Similarly, there are various other drawbacks being attached with the virtualization paradigm. In data centers and server farms, the virtualization technique is typically used for creating multiple VMs out of physical machines and each VM has its own operating system (OS). Through this solid and sound isolation enacted through automated tools and controlled resource-sharing, multiple and heterogeneous applications are being accommodated in a physical machine. That is, the hardware-assisted virtualization enables disparate applications to be run simultaneously on a single physical server. With the virtualization paradigm, various kinds of IT infrastructures (server machines, storage appliances, and networking solutions) become open, programmable, remotely monitorable, manageable, and maintainable. However, because of the verbosity and bloatedness (every VM carries its own operating system), VM provisioning typically takes a few minutes. This is a big setback for real-time and on-demand scalability.

The other widely expressed drawback that is being closely associated with virtualization is that the performance of virtualized systems also goes down due to the excessive usage of precious and expensive IT resources (processing, memory, storage, network bandwidth, and so on). The execution time of virtual machines is on the higher side because of multiple layers ranging from a guest OS, a hypervisor, and the underlying hardware.

Finally, the compute virtualization has flourished, whereas the other closely associated network and storage virtualization concepts are just taking off.  Precisely speaking, building distributed applications and fulfilling varying business expectations mandate for the faster and flexible provisioning, high availability, reliability, scalability, and maneuverability of all the participating IT resources. Compute, storage, and networking components need to work together in accomplishing the varying IT and business needs. With more virtualized elements and entities in an IT environment, the operational complexity is bound to grow rapidly.

Move over to the world of containerization; all the preceding barriers get resolved in a single stroke. That is, the evolving concept of application containerization coolly and confidently contributes to the unprecedented success of the software portability goal. A container generally contains an application/service/process. Along with the primary application, all of its relevant libraries, binaries, files, and other dependencies are stuffed and squeezed together to be packaged and presented as a comprehensive yet compact container. The application containers can be readily shipped, run, and managed in any local as well as remote environments. Containers are exceptionally lightweight, highly portable, rapidly deployable, extensible, horizontally scalable, and so on. Furthermore, many industry leaders have come together to form a kind of consortium to embark on a decisive and deft journey towards the systematic production, packaging, and delivery of industry-strength and standardized containers.

This conscious and collective move makes Docker deeply penetrative and pervasive. The open-source community is simultaneously spearheading the containerization conundrum through an assortment of concerted activities for simplifying and streamlining the containerization concept. The containerization life cycle steps are being automated through a variety of third-party tools.

The Docker ecosystem also grows fast in order to bring in as much automation as possible in the IT landscape. Container clustering and orchestration are gaining a lot of attention, thereby geographically distributed containers and their clusters can be readily linked up to produce bigger and better process-aware and composite containers. The new concept of containerization assists with distributed computing. Containers enable the formation of federated cloud environments in order to accomplish specialized business targets. Cloud service providers and enterprise IT environments are all set to embrace this unique compartmentalization technology in order to escalate the resource utilization and to take the much-insisted infrastructure optimization to the next level. On the performance side, there are sufficient tests showcasing Docker containers achieving the bare metal server performance. In short, the IT agility through the DevOps aspect is being guaranteed through the smart leverage of the Docker-enabled containerization and this, in turn, leads to business agility, adaptivity, and affordability.