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Looking to find out what docker is? Welcome to this concise article with the introduction to docker.
Docker can be beneficial if you’re working on a team with developers worldwide because it means less context switching and more efficient development time. Docker also lets you keep an eye on all the changes that are happening in your application’s environment at any given time by letting you track down issues faster.
What Docker Is.
Docker can be defined as a portable, lightweight virtualization solution that makes it possible for us to have our code run on the cloud. It’s an orchestration tool that enables us to manage many Docker containers in a single process.
Docker is a tool that makes it really easy to manage web applications. It’s an open-source project that allows you to create containers for keeping separate environments, easily share commands with other developers, and reuse pieces of code.
Why use Docker?
Docker instantly helps programmers to install applications easily on their local computers, servers and web-based servers. It is basically a package manager for applications, but it also allows you to create isolated environments that can run on your computer. This helps you avoid introducing third-party software into the application’s environment, which could conflict with other locally installed programs.
Docker can help if your development team consists of people who need to use the same code simultaneously but are using different operating systems or different versions of an operating system. For example, you can build an application in one system and test it in another by running the environment in a container.
It is especially useful for testing an application against multiple versions of libraries and dependencies used during production.
Docker containers are not dependent on the underlying physical system. This allows you to move an application between different operating systems or to migrate it between cloud hosting providers.
These containers maintain the application in its own isolated space, which means you don’t have to worry about potential issues caused by hooking up an application to a database with different versions or configuration files.
You might be wondering how exactly Docker works and what all the uproar is all about. First, let’s take a look at some of the jargon used in Docker:
What is a docker container?
A container is basically an environment with everything needed for your program (including libraries, runtime, system tools). It can also include other containerized applications that provide services to the first application. Containers are created from images, which are basically templates for different types of containers. A container is basically an instance of an image. It is an application with its own memory, space and fully functioning ecosystem.
What is a docker image?
There are two kinds of images: There’s a “root” image, which is the primary image used to create all other images, and there are “child” images, which are created from the root image. For example, you might have your own base image that includes tools or libraries you commonly use in your projects. You can then create an image containing just this base layer and then rebuild it with different layers representing features added to it (like web server or database).
An image is essentially a snapshot of the container in state at a certain point in time. Images are made from layers, which are essentially files that represent the various system resources available to the container.
Images are built by converting compressed packages into layers.
What was used before Docker?
Docker has become really widespread, but before Docker was released, there were other tools for creating reusable containers. The most common tool was Vagrant, which allows you to create virtual environments laid out exactly as you want. Unfortunately, vagrant also uses VirtualBox under the hood and it’s not compatible with Docker because of this reason.
It’s possible to copy existing images and create new ones by modifying them. However, you can’t just pull images straight from GitHub without any modifications. Docker has a built-in registry that lets you know which images are ready for use and which aren’t, so it’s better to create new images than modify existing ones.
How do docker containers communicate with each other?
Docker uses virtual networks to allow containers to communicate in the same environment they are in when created. Docker will create its own bridge inside the container that allows the containers to communicate to networks created by the host system. For example, you can use your Docker host’s port 8080 to talk to one of your containers on Port 8000. The fact that Docker uses virtual networks means it doesn’t really need an internet connection to function.
What is Docker hub?
Docker Hub is a cloud service for sharing and distributing Docker images. It’s a hosting service where you can store your own private repositories along with public ones. Then, you can pull or push an image to or from these repositories through the Docker CLI, just like you do with your local ones.
Docker has been a very hot topic among the programming community now. It was first released in 2013 and since then, it has been used successfully by lots of big players. There is a big community around it as well as many developers using it all over the world. It’s great to see how Docker made its way into the development world and we can expect it to live for a long time yet.
Read this article to see how to install docker.