One of the hot technologies right now is containers – and with good reason. Containers offer many benefits over traditional virtual machines (VMs). These benefits include:
- Rapid deployment
- Performance improvements
- Support for microservices
I selected the containers topic as one of my top three favorite topics from the upcoming CompTIA Linux+ (XK0-005) release. For those curious, my other two favorite topics were Git and Vim. Be sure to read the whole series:
- My CompTIA Linux+ Favorites: Top 3 Favorite Topics From Linux+ (XK0-005)
- My CompTIA Linux+ Favorites: Git
- My CompTIA Linux+ Favorites: Vim
Containers have become a go-to solution for services hosted on-premises as well as in the cloud and it provides an entirely different kind of virtualization from virtual machines. Where VMs virtualize the hardware and then expect sysadmins to install an operating system (OS) and applications, containers virtualize above the OS layer. With Linux-based containers, administrators only need to concern themselves with application management.
Both VMs and containers are part of CompTIA Linux+ (XK0-005), so expect to see a solid compare-and-contrast section. CompTIA continues its vendor-agnostic perspective during the virtualization section.
The Container Lifecycle
To understand container management, you must first understand the container lifecycle. Container images are built, then pulled to host systems and run. Containers may be stopped or paused on these hosts, too. Finally, if a container is no longer needed, it is removed. Dockerfile configuration files manage image settings and these files have a straightforward structure and syntax.
Expect to learn about these container topics and more:
- Creating a container image
- Pulling containers to a system from a repository
- Starting and stopping containers
Management tasks, such as resource monitoring and image identification, are also key topics.
Learning Container Management
Linux is the preferred host for containers, so it behooves all who interact with container virtualization to understand basic system administration and performance monitoring. Deploying a container solution without being able to monitor system resources, view log files, manage network settings and update security configurations is asking for trouble. Not only does CompTIA Linux+ (XK0-0005) cover containers, but it also provides the day-to-day working knowledge users, developers and administrators need to manage deployments.
Container networking is almost a topic unto itself. Exposing ports and interconnecting containers permits applications to be accessible to both other programs and users. Access to containers through the network fabric is kind of the point – containers offer services outward rather than acting as standalone devices.
The Importance of Labs
Speaking of revolutionizing virtualization, the new CompTIA Linux+ (XK0-005) is supported by a series of labs to provide hands-on opportunities. For the first time, labs are run on containers that improve the user experience and demonstrate the flexibility and importance of this approach to virtualization.
Containerization and the Importance of Linux Fundamentals
Containerization is a critical subject, and it represents the third of my three favorite CompTIA Linux+ (XK0-005) topics. Alongside Git and Vim, containers continue to demonstrate both the importance of Linux fundamentals and the deployment of the latest technologies.
I feel privileged to author the latest CompTIA Official Linux+ (XK0-005) Instructor and Student Guides and I’m confident that the body of knowledge will help prepare Linux admins for the next challenges in their IT lives. As a mix of both fundamental topics and advanced new subjects, this iteration of CompTIA Linux+ is an important steppingstone for shifting its focus to Linux administration.