Containers are lightweight and portable software environment that allows applications to easily scale and run on any platform. Containers are abstraction at the application layer that packages code and dependencies together. Multiple containers can run on the same machine and share the OS kernel with other containers. Containers uses Operating system level virtualization in which kernel allows the existence of multiple isolated user spaces instances.
Containers makes it easier for everyone to deploy, update and scale apps and services. Containers already contains all the dependencies required to run the application, so we no longer have to install dependencies in the host Operating System.
A container is served up by software (container platform like Docker) which runs container Image. A container image is a lightweight, stand alone, executable package of a piece of software that includes everything needed to run it: code, runtime, system tools, system libraries, settings and other dependencies. Containerized software runs always runs the same regardless of the platform and environment. Advantages of using platform like Docker include – Hybrid Cloud Portability, New levels of application security, IT cost efficiency etc.
Specialized software like Kubernetes exists for automatic deployment, scaling and management of containerized applications. Some of the key features of Kubernetes are – Automatic binpacking, Self-healing, Horizontal scaling, Service discovery and load balancing, automated rollouts and rollbacks, Secret and configuration Management, Storage orchestration, Batch execution.
Some of the important advantages of using containers in Cloud Computing environment are:
- Portability: Containers are platform independent. Once built they can be used anywhere, on any platform as containers already include the application code, necessary dependencies and configurations. This enables us to easily and reliably run applications on different environments such as servers, desktops, testing or production environment etc. It speeds up development process and makes it easier to switch between cloud providers.
- Resource efficiency: Size of containers is generally in megabytes whereas Virtual Machine generally takes up more than several gigabytes. Containers require less resources than running virtual machines, therefore we can add more computing workload when using containers.
- Ease and Speed of Provisioning: Containers can be provisioned in few seconds, making them suitable in situations when we need to quickly scale up during sudden spikes.
- Improved Productivity: Containers significantly reduces time needed for development, testing and deployment of resources as it eliminates environmental inconsistencies. Testing also becomes easier as there is no difference between running your application locally, on a test server or in a production server.