Containerization is a type of virtualization in which all the components of an application are bundled into a single container image and can be run in isolated user space on the same shared operating system.
Containers are lightweight, portable, and highly conducive to automation. As a result, containerization has become a cornerstone of development pipelines and application infrastructure for a variety of use cases. Understanding what containerization is, and how to implement it securely, can help your organization modernize and scale its technology stacks.
Containerization works by virtualizing all the required pieces of a specific application into a single unit.
Under the hood, that means containers include all the binaries, libraries, and configuration an app requires. However, containers do NOT include virtualized hardware or kernel resources.
Instead, containers run “on top” of a container runtime platform that abstracts the resources. Because containers just include the basic components and dependencies of an app without additional bloat, they are faster and more lightweight than alternatives like virtual machines or bare metal servers. They also make it possible to abstract away the problems related to running the same app in different environments. If you can provide the underlying container engine, you can run the containerized application.
It’s easy for the uninitiated to be confused by the difference between containerization (what containerization software like Docker enables) and traditional server virtualization (what hypervisors like HyperV and VMware ESXi enable). In simple terms, the difference boils down to this:
Server virtualization is about abstracting hardware and running an operating system. Containerization is about abstracting an operating system and running an app.
They both abstract away resources, containerization is just another level “up” from server virtualization. In fact, containerization and server virtualization aren’t mutually exclusive. You can run containerized apps on top of a container engine that is deployed within a virtual machine.
To get a better idea of exactly how containerization works, let’s take a closer look at how all the pieces — from hardware to the containerized application — fit together.
Given what we know, we can see that containerization bundles only what an app needs into a single unit and allows the apps to run anywhere the container engine exists. With that in mind, it becomes easy to see the benefits of containerization which include:
Knowing the benefits of containerization is important, but understanding real-world use cases allows you to put the knowledge into practice. Here are some examples of popular containerization use cases:
Kubernetes, also known as K8s, is a popular tool to help scale and manage container deployments. Containerization software like Docker or LXC lacks the functionality to orchestrate larger container deployments, and K8s fills that gap. While there are other container orchestration tools (like Apache Mesos and Docker Swarm), K8s is by far the most popular.
Of course, “management” and “orchestration” are vague terms. So, what exactly can Kubernetes do? Let’s take a look:
You may think that because containers are isolated, they are “secure”. Unfortunately, it’s not that simple. While it’s true containers are isolated from one another in userspace, misconfigurations, vulnerabilities, and malicious actors all pose threats. Simply put: securing your containers is a must.
There are many specific container security considerations you must account for when containerizing applications. For example, continuous monitoring of container registries for new vulnerabilities and leveraging container firewalls are important aspects of comprehensive container security. Additionally, securing the host operating system your container engine runs on is a must.
Of course, securing containerized applications means you must take application security (appsec) seriously as well. That means taking a holistic view of your environment, creating security profiles, identifying threats, and leveraging tools like Interactive Application Security Testing (IAST) solutions and Web Application Firewalls (WAFs) where appropriate.
Check Point products like CloudGuard are purpose-built with DevOps pipelines and container security in mind. As industry leaders in the containerization security space, we know what it takes to get container security right. For a deep dive into the world of containerization security, download our free Guide to Container and Kubernetes Security today. In that free guide you’ll learn about:
Additionally, if you’re responsible for securing multi-cloud environments, you’re welcome to read our free Achieving Cloud With Confidence in the Age of Advanced Threats whitepaper. In that paper, you’ll gain robust insights into threat prevention and infrastructure visibility in multi-cloud environments.