Understanding containers

Containers are technologies that allow the packaging and isolation of applications with their entire runtime environment—all of the files necessary to run. This makes it easy to move the contained application between environments (dev, test, production, etc.) while retaining full functionality. Containers are also an important part of IT security. By building security into the container pipeline and defending infrastructure, containers stay reliable, scalable, and trusted. You can also easily move the containerized application between public, private and hybrid cloud environments and data centers (or on-premises) with consistent behavior and functionality.

Containers help reduce conflicts between your development and operations teams by separating areas of responsibility. Developers can focus on their apps and operations teams can focus on the infrastructure. And, because containers are based on open source technology, you get the latest and greatest advancements as soon as they’re available. Container technologies—including Podman, Skopeo, Buildah, CRI-O, Kubernetes, and Docker—help your team simplify, speed up, and orchestrate application development and deployment.

Containers share the same operating system kernel and isolate the application processes from the rest of the system so the whole thing can be moved, opened, and used across development, testing, and production configurations. Because they are lightweight and portable, containers provide the opportunity for faster development and meeting business needs as they arise. 

Containers let development teams focus on their apps while operations teams focus on the infrastructure. Container orchestration is the way you manage these deployments across an enterprise.

Kubernetes is an open source platform that automates Linux container operations. It eliminates many of the manual processes involved in deploying and scaling containerized applications. Kubernetes gives you the platform to schedule and run containers on clusters of physical or virtual machines. Kubernetes architecture divides a cluster into components that work together to maintain the cluster's defined state.

Red Hat® OpenShift® 4 is an enterprise-ready Kubernetes platform. It gives developers self-service environments for building, and full-stack automated operations on any infrastructure.

You can deploy containers for a number of workloads and use cases–big to small. Containers give your team the underlying technology needed for a cloud-native development style, so you can get started with DevOps, CI/CD (continuous integration and continuous deployment), and even go serverless.

Container-based applications can work across highly-distributed cloud architectures. Application runtimes middleware provides tools to support a unified environment for development, delivery, integration, and automation.

You can also deploy integration technologies in containers, so you can easily scale how you connect apps and data, like real-time data streaming through Apache Kafka. If you're building a microservices architecture, containers are the ideal deployment unit for each microservice and the service mesh network that connects them.

When your business needs the ultimate portability across multiple environments, using containers might be the easiest decision ever.

Nothing is secure by default. Static security policies and checklists don’t scale for containers in the enterprise, so you need to know how to build better security into the container pipeline.

Although sometimes confused, Docker is not the same as a traditional Linux container. Docker technology was initially built on top of the LXC technology—which most people associate with "traditional" Linux containers—though it’s since moved away from that dependency. LXC was useful as a lightweight virtualization, but it didn’t have a great developer or user experience. The Docker technology brings more than the ability to run containers—it also eases the process of creating and building containers, shipping container images, and versioning of images, among other things.

Traditional Linux containers use an init system that can manage multiple processes. This means entire applications can run as one. The Docker technology encourages applications to be broken down into their separate processes and provides the tools to do that. This granular approach has its advantages.

Virtualization provisions the resources that containers can use. These virtual machines (VMs) are environments in which containers can run, but containers aren’t tied to virtual environments. Some software—like Red Hat® OpenShift® Virtualization—can both orchestrate containers and manage virtual machines, but that doesn't mean the 2 technologies are the same.

VMs have finite capabilities because the hypervisors that create them are tied to the finite resources of a physical machine. Containers, on the other hand, share the same operating system kernel and package applications.

Red Hat does a lot of work on container technologies with the greater open source community. Our engineers help improve features, reliability, and security to make sure your containers perform and remain stable. Red Hat's also the second largest contributor to the Docker and Kubernetes codebases and works with the Open Container Initiative and the Cloud Native Computing Foundation. As with all open source projects, Red Hat contributes code and improvements back to the upstream codebase—sharing advancements along the way.

Red Hat’s container-focused solutions and training offerings give you the infrastructure, platform, control, and knowledge to take advantage of everything containers have to offer.