Containers – What are they and how do they work?
Containers may be described as packages that include everything needed to run a single application or micro service. This includes its dependencies and run-time libraries. Containers allow the application to be run quickly and reliably from anywhere, right from desktop computers to physical and virtual servers and even the cloud.
The container is abstracted away from the host operating system (OS). Each container shares the OS kernel with other containers rather than including its own full OS. Access to underlying OS resources is limited. As such, a containerized application can be run on different infrastructure types such as the cloud, virtual machine, bare metal and so on, without the need for refactoring the application for each IT environment.
Since containers typically share the machine’s OS kernel and don’t have the overhead of having a full OS within each container, they are often regarded as being more “lightweight” than virtual machines (VMs).
Containerization may be defined as a type of OS virtualization wherein applications are run within isolated user spaces (containers) that all share the same OS kernel. It is the encapsulation of an application and the environment required to run it so it can be efficiently and consistently run across several different computing platforms.
Containerization is emerging as the preferred approach for software development and DevOps pipelines. The creation and deployment of applications are faster and more secure with containerization.
When code is developed using traditional methods in a specific computing environment and transferred to a different computing platform, it can often result in errors. However, containerization effectively eliminates this problem by encapsulating the entire application code along with its related libraries, dependencies and configuration files required for it to run.
Pros
- One of the major advantages of containerization is that it provides a fast and lightweight infrastructure for you to run your applications. The relatively lightweight containers are more flexible, and you can create and move them more quickly than VMs.
- Containerization supports policy-based optimization. You can use an automation layer to locate, auto-migrate and execute on the best platform.
- Containerization is helpful in lowering your software development and operational costs.
- Containerization also provides greater scalability. Compared to VMs, many more containers can be created and run on a physical server since they don’t require a full OS to be included in each container. In addition, monolithic applications can be broken down into smaller micro services using containers. You can then scale and distribute the individual features.
Cons
- One of the major drawbacks of containerization technology is that it requires a significant amount of work to set up in an organization so that it performs efficiently.
- Since the technology is relatively new, the required application support and dependencies still remain insufficient.
- It’s hard to find qualified container developers.
- Containers share the host OS kernel. That said, in the event of the kernel becoming vulnerable, all the associated containers would become vulnerable too.
- Container technology can be more expensive in terms of application development costs.
The containerization technology provides tremendous portability across computing platforms and environments. It allows the developers to write the application once and then run it anywhere they like.
Being a key component of the private cloud, containers are fast emerging as a game-changer for many businesses. Private cloud has become the favored approach for organizations to deliver the flexibility and control required while also enabling efficient consumption of multiple cloud services.