Oracle is expanding its embrace of Docker containers with a new official image for Oracle Linux on the Docker Hub registry.
The Docker Hub registry is an online repository of Docker apps that anyone can pull from to deploy on a Docker engine host. Docker is open-source technology that enables container-based application virtualization. The availability of Oracle Linux on Docker Hub is not part of any larger partnership between Oracle and Docker Inc., the lead commercial sponsor behind Docker.
"The Docker Hub is freely available for folks to upload their components, and there's no financial requirement," Wim Coekaerts, senior vice president, Linux and Virtualization Engineering, at Oracle, told eWEEK. "We just want to have an official Oracle account on GitHub and Docker so that Docker users know that these are the official images coming from Oracle."
Having an officially sanctioned application from Oracle is important, since there are already several unofficial versions of Oracle Linux on Docker Hub. Coekaerts noted that the Docker Hub registry is in essence a marketplace where anyone can publish images.
"Our official Docker image goes through Oracle QA [quality assurance] first, and Docker build validation as well," he said. "That's one of the reasons Oracle is starting to publish our own images, so customers or developers can get them directly from us and know they are QA'd by Oracle and they have a way to get support if they need it."
Docker has become a popular tool for developers, and Oracle wants to help ensure that Oracle Linux is easily available, Coekaerts said. Docker has been embraced by multiple large IT vendors, including IBM, Microsoft, VMware and Amazon, as a technology for virtualized application deployment.
The Docker engine itself needs to run on top of an operating system host. Several Linux vendors, including Red Hat with Project Atomic and Canonical with Snappy Ubuntu Core, are building Docker container-optimized versions of their Linux distributions. Oracle does not currently have its own specific optimized operating system version for Docker, though Coekaerts said that Docker deployment isn't that hard.
"It's very easy to do a minimal Linux install and add Docker on top," he said.
He added that a minimal Oracle Linux installation has a very small setup and is not much different in size compared with Project Atomic. That said, there is the future potential for another approach on Oracle Linux for Docker host optimization.
"Oracle is looking at some options to further streamline, but in the context of Oracle Linux and not a separate project," Coekaerts said.
From a virtualization standpoint, Oracle has its own virtualization product known as Oracle VM, which is based on the open-source Xen hypervisor. There is a potential intersection between Docker and Oracle VM for application deployment.
One way to combine Oracle VM and Docker is to use a large virtual machine (VM) to separate users, departments or application stacks, according to Coekaerts. Then within the VM, the organization can deploy the various app components for that user or department or stack inside Docker containers.
"This allows you to isolate users and do resource management with dedicated kernel versions etc., and you use Docker to isolate apps within the VM," he said.
Looking forward, there are a number of different Docker-related initiatives at Oracle, including continuing to update application images. Another potential effort is an attempt to make it easier to go from Docker to a VM and back.
"For example, there should be one way of packaging the OS or application so it can run inside Docker, or inside a container, or inside a VM, or on baremetal, rather than having one for each," Coekaerts said.
Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.