Prior to 2014, Docker was not well-known, but that all changed over the course of the year. The open-source Docker container virtualization project got its start in March 2013, and in 2014 hit its full stride, achieving its 1.0 release milestone and the embrace of many of the world's leading IT vendors.
To understand why Docker has become popular in 2014, it's important to take a step back to see what Docker enables and what the disruption it brings to the market means.
Docker represents a different model for virtualization than the traditional hypervisor virtual machine (VM) approach that VMware's ESX, Microsoft's Hyper-V, Xen and the open-source Kernel-based Virtual Machine (KVM) technologies employ. With a traditional hypervisor, each VM needs its own operating system. However, with Docker, applications sit inside a container that resides on a single host OS that can serve many containers.
"If the problem is, how do I take an application and deploy it across a large number of servers, there is no need to take an application that is measured in megabytes, combine it with an operating system that's in gigabytes and run that whole thing on top of a hypervisor that is running on top of another host operating system," Docker Inc. CEO Ben Golub said in a video interview with eWEEK in 2013.
The promise of Docker goes further and isn't just about the virtualization container, but more importantly, is also about the promise of portable virtualized applications. Docker provides a format that can enable an application developer to package an application that can rapidly be deployed to any Docker-ready host.
In a very real sense, what Docker promises is somewhat akin to the original promise of Java: write code once and run it anywhere. It's a promise that in the cloud era is increasingly valuable, and it's one Docker delivers upon.
While there were early adopters of Docker in deployment, the big milestone event for Docker occurred on June 9, when Docker 1.0 was formally released. With a 1.0 release comes the promise of stability and the ability for enterprises to reliably deploy the technology. With the Docker 1.0 release, Docker Inc., the lead commercial sponsor behind the Dock open-source effort, also launched its commercial support efforts and the Docker Hub.
The Docker Hub is a central repository for "Dockerized" applications that can be deployed on a Docker host. In December at the Dockercon Europe event, Docker Inc. released its Docker Hub Enterprise (DHE) on-premises product, which is aimed at bringing workflow capabilities for developers and systems administrators "behind the enterprise firewall," company officials said.
As part of the Dockercon Europe event, the open-source Docker project expanded with new orchestration services. Docker Machine enables easier Docker host deployments, Docker Swarm provides clustering and Docker Compose provides application assembly services.
Docker also thrived in 2014 as a result of multiple industry partnerships. Docker is supported in the Red Hat Enterprise Linux 7 release, which debuted in June. Amazon, a key supporter of Docker, launched the EC2 Container service during the Amazon re:invent conference in November.
IBM has also publicly embraced containers; the company sells Docker Hub Enterprise as well a new IBM Containers service.
Perhaps more noteworthy, though, is the fact that vendors that in many respects could be considered rivals to Docker have instead chosen to embrace it. In a surprise move, VMware announced its support of Docker in August.
"The best way to deliver containers is through a virtual machine," VMware CEO Pat Gelsinger said during his VMworld 2014 keynote address last summer.
Also getting into the act, Microsoft provides support for Docker on the Azure cloud and is working to enable Docker on Windows Server.
The reason vendors have chosen to partner and embrace Docker is simple: Developers are typically focused on building their own applications and not the underlying infrastructure. Docker offers a new optimized approach for an old problem—how to easily and rapidly deploy applications.
While 2014 was a year of firsts for Docker, 2015 will be a year of maturation and further expansion. Leading-edge application developers and technology vendors have already seen the promise of Docker, and in the new year, it's more likely than not that mainstream enterprise and developer adoption will occur.
Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.