Containers are a way to package your application’s source code, configuration, dependencies, into a single file. A Single file can be used to run small microservices or large software applications. It sits on the top of a physical server and its host operating system which means containers share the same operating system. Virtual machines run on the top of the emulating software called the Hypervisor. A Hypervisor is also known as a Virtual Machine Monitor that creates and run Virtual machines. It allows the host machine to support multiple guest VMs by virtually sharing its resources. In virtual machines, every VM has its own OS whereas in containers they share the same Kernel of the host machine which makes it less heavy.
WHY CONTAINERS ARE USED IN DEVOPS?
Sometimes, a problem occurs when the application is moved from one environment to another. (From a developer’s laptop to a virtual environment for testing, or from a staging environment to the production environment) Problems like this when the required configuration and software environment is not the same on both the environments “Maybe the developer relies on Debian but the production is on Red hat” this type of thing may happen. These problems can occur any time if there is a difference between the network, storage or security policies between the two environments.
To solve this problem, Containers come into the picture. It consists of the source code of the application, configuration files, libraries, and dependencies that are necessary to run the application. You can run a Container in any environment as these things cannot be different in any environment. They make the process of deployment faster when different teams are working simultaneously. Since they behave the same way in different environments, Containers are reliable and easy to use for developers. DevOps is a method through which applications are deployed faster and Containers help DevOps teams achieve that speed
If multiple or more heavy applications are being deployed, then teams can use Multiple Cluster which is known as container cluster and there are also container Orchestrator tools that are used to manage the multiple containers. Some of them are are Kubernetes(k8s), Docker, ECS for Amazon Web service.