If you’re an organizational developer who has already followed the DevOps movement or someone who follows the latest software development trends, you might have probably heard of the buzz word “Docker”. A new infrastructure feature for server-side code deployments has been silently taking over. The Docker release was first made in 2013, and the use of developer deployments grew exponentially since then. Over the last seven years, Docker has become the de facto norm for large deployments.
As businesses migrate online due to competition (not to mention COVID-19), it is becoming ever necessary to find the best way to handle the infrastructure. Docker allows development teams to provide more efficient, repeatable, and testable systems that can be implemented with a click of a button on a large scale.
So, what is Docker?
Docker is an open-source project which enables the development of container-based applications. A container idea is to be a tiny, stateless environment for operating a software item.
Originally designed for Linux, Docker is now running on macOS and Windows. Let us look at some of the components we would use to create Docker-containerized applications to understand how Docker works.
Any container in Docker begins with a Docker file. A Docker file is a text file that is written into an easy to understand syntax with instructions for generating an image of the Docker. A Docker file sets the operating system underlying the container, the languages, environmental variables, and file locations, network ports, and other components required — and what the container will do when it is run.
After you’ve written your Docker file, you invoke the Docker to build a utility or to create a picture based on that Docker file. Although a Docker file is the series of instructions for creating an image, a Docker image is a portable file that contains specifications for which container software components are used and how. Because a Docker file probably contains some online repository software package directions, you should be careful to offer unique versions or your Docker file could produce conflicting pictures depending on whether it is being invoked.
The Docker daemon is what executes commands sent to the Docker Client, such as the building, execution, and distribution of your container. The Docker daemon is running on the server, but you can never directly communicate with the Daemon as a user. The Docker Client may also function on the host, but this is not necessary. It can run on another machine and communicate with the host machine Docker Daemon.
Docker Engine is the heart of Docker, the technology that builds and runs the containers that are the base client-server. In general, when someone usually says Docker and doesn’t speak about the business or the entire project, it’s Docker Engine.
How does Docker work?
A Docker engine of containers consists of the Docker daemon and other utilities. Docker Daemon is the background mechanism for the management of containers by using the REST HTTP protocol to accept commands from the local or remote Docker client. Docker is also said to comply with Docker daemon’s client-server architecture.
You get the Docker engine, the Docker control line (Docker client) interface, and other GUI utilities when you install Docker on your device. It will start the Docker daemon when you start your Docker.
So, why is Docker gaining popularity suddenly?
- Ease of Use
Docker has allowed the use of containers and to build and test portable applications easily for anyone, be it a developer, system manager, architect, etc. It allows anyone to bundle an app on their desktop, which can then run on any public cloud, private cloud, or even bare metal without modification. “Build once and run somewhere” is the motto.
Containers in dockers are very light and fast. As containers only contain sandboxes in the kernel, fewer resources are used. Compared to VMs that could take longer because they have to boot a complete virtual operating system every time, you can build and run a Docker packet in seconds.
- Docker Hub
Docker users benefit from the increasingly rich Docker Hub ecosystem, which you can see as an “app store of Docker images.” Docker Hub has tens of thousands of publicly accessible images generated by the community. It is extremely simple, with little or no change, to search for images that satisfy your requirements.
- Modularity and Scalability
Docker makes it easy to separate the features of your application into individual containers. In a container and your Redis server, for example, you may have a Postgres database running while your Node.js app is running in another one. With Docker, it’s easier to connect these containers to build your application and make it easy in the future to independently scale or upgrade components.
Docker Containers solve a lot of issues, but they’re not cure-alls. Some of its vulnerabilities are by design, while others are by-products of its design. They use controlled portions of the resources of the host operating system, and many of these applications use a highly managed OS kernel. As a result, containerized systems are not as fully isolated as virtual machines but provide the great majority of workloads with adequate isolation
With the container design developing and continuing to gain popularity, more players will likely come into the market, but we should eventually come up with integrated, interchangeable container technologies that gives more power and control to developers.