What is Docker?
To get started talking about Docker you need to have a little understanding of what Containers are. The two concepts are closely related. It’s hard to describe one without the other.
Containers – a way to package an application and all of its dependencies into a single image. This image runs in an isolated environment that does not affect the host operating system. Containers allow you to separate the application from the infrastructure: developers do not need to think about the environment in which their application will work, whether there will be the necessary settings and dependencies. They just build the application, package all dependencies and settings into a single image. This image can then run on other systems without worrying about the application not launching.
Docker – a platform for developing, shipping, and running containerized applications. This platform allows you to create containers, automate their launch and deployment, and manage the life cycle. It allows you to run multiple containers on a single host machine.
In 2010, Solomon Haykes and Sebastien Pahl created Docker during the Y Combinator startup incubator group. In 2011, the platform was launched. Hykes originally started the project in France as part of an internal dotCloud project.
What is Docker used for?
Docker packages the application and all its dependencies into a virtual container that can run on any Linux server. This is why we call them containers. Because they have all the required dependencies contained in a single software package.
This platform very well suited for solving the above tasks:
- Convenient transfer of the server project to the client
- Ensuring replicability of servers
- Ensuring reusability of previously created server configurations
Separately, I would like to note that docker is also extremely convenient for updating previously installed versions of the product and for creating test servers that are completely identical to “natural” ones.
With Docker we can:
- Create images in which our applications are located;
- Create containers from images to run applications;
- Distribute images through Docker Hub or another image registry.
Moreover, Docker containers can run not only on their servers but also in the cloud. Firstly, it will allow you not to deal with the selection, purchase, and configuration of servers. Secondly, cloud providers have developed many ready-made services that provide additional benefits. For example, Kubernetes on the VK Cloud Solutions (formerly MCS) platform manages the life cycle of containers, automatically scales under load changes, and helps build a fault-tolerant system.
Docker deployment, scaling, management
With Docker, you can quickly deploy and scale your applications in any environment and remain confident that your code will work.
AWS services such as AWS Fargate, Amazon ECS, Amazon EKS, and AWS Batch make it easy to use and manage Docker containers at scale.
Developers do not need to use Docker to create containers, but it makes developing, deploying, and managing containers easier, simpler, and safer. In essence, this platform is a set of tools for developing, deploying, running, updating, and stopping containers using simple commands and automation tools based on a single API.
