By Zeynep Koch-Oracle on May 22, 2015
Happy Friday everyone!
We have a great technical article for you this Friday. In this article, you learn how to customize a Docker container image and use it to instantiate application instances across different Linux servers. This article describes how to create a Dockerfile, how to allocate runtime resources to containers, and how to establish a communication channel between two containers (for example, between web server and database containers).
Ginny Henningsen quotes "Docker is exciting because it can easily capture a full application environment into a virtual container that can be deployed across different Linux servers. System administrators and software developers are learning that Docker can help them deploy application images on Linux quickly, reliably, and consistently—without dependency and portability problems that can inject delays into planned deployment schedules. Docker containers can define an application and its dependencies using a small text file (a Dockerfile) that can be moved to different Linux releases and quickly rebuilt, simplifying application portability. In this way, "Dockerized" applications are easily migrated to different Linux servers where they can execute on bare metal, in a virtual machine, or on Linux instances in the cloud. "
As shown in Figure 1, Docker containers consume fewer resources than "heavyweight" hypervisor-based solutions. Hypervisor-based solutions host a full-blown operating system instance in each virtual machine guest, but this also allows them to support different operating systems. (Oracle VM, for example, can host Oracle Linux, Oracle Solaris, and Microsoft Windows in virtual machines.)