Docker was created with the intent to create a simplified approach to building, deploying, and running applications across different environments. As a staple technology in modern software development, it is important for any aspiring or active developer to learn about how and when to use Docker when building software.
If you're new to Docker or simply looking to learn more about the fundamental principles behind the technology that has become almost synonymous with microservice architectures and containerization, look no further. In this article we will be taking a look at the history of Docker and what makes it so crucial to modern software engineering.
Background of Docker In 2013, French software engineer Solomon Hykes launched the Docker project. Hykes' ambition was to fulfill every developer's dream of a simplified way to build and deploy application. Docker's initial release in March 2013 was met with enthusiasm by developers and organizations and quickly became popular in those circles. The key to Docker's enormous success was its ability to deliver a uniform runtime environment, independent of the system where the application would be hosted.
Docker Inc. was established to provide commercial support to the Docker project. Since then, Docker has become a staple technology in software development, utilized by countless developers and organizations to build and deploy applications.
As a result Docker now flaunts a flourishing ecosystem of tools and services, including container orchestration platforms such as Kubernetes and Docker Swarm, as well as cloud-based container registries like Docker Hub and Google Container Registry.
What is Docker? Docker functions as a containerization platform that allows developers to create, deploy, and manage containerized applications. It provides an easy-to-use interface for building and running applications in isolated environments, enabling greater portability and flexibility across different computing environments.
With Docker, developers can package their application code, along with all necessary dependencies, libraries, and configuration files into a container that can be easily shared and deployed across different operating systems and cloud platforms.
Docker provides a standardized way to build and run containers, making it easier for developers to collaborate on projects and for operations teams to manage and scale applications.
With a rich ecosystem of tools and services, Docker provides tools to help developers deliver new software easily. Notable examples include tools such as Docker Hub, a centralized repository for storing and sharing container images, and Kubernetes, a powerful orchestration tool for managing large-scale container deployments.
Why Is Docker Important? Docker is a vital tool for software developers because of its ability to simplify application development, testing, and deployment. Docker provides developers with various features that simplify day-to-day software development, such as:
Consistent Runtime Environment : By providing a consistent runtime environment, developers can use Docker to ensure that their applications run the same way across different environments, such as staging or production. Docker helps developers to achieve consistency across different development environments, thereby reducing errors and simplifying testing and deployment.Portable Containers : Portable Containers enable developers to simply move their application from one environment to another, such as from testing to staging and finally to production. Regardless of the underlying infrastructure, portable containers make managing and deploying apps simpler.Isolation through Containers : Docker uses containerization to isolate applications and their dependencies from the host system and other applications running on the same system. Isolated applications reduce the risk of conflicts and errors caused by dependencies, thereby simplifying managing and scaling applications.Proper Collaboration : Docker makes it easier for developers to collaborate on projects by providing a standard environment for all team members. This reduces the risk of compatibility issues and makes it easier to share code and work on different application parts simultaneously.Easier to Test and Deploy : Docker makes it easier to rapidly prototype, test, and deploy applications, which is critical in today's fast-paced development environment. Docker containers can be quickly spun up and down, enabling developers to experiment with different configurations and test new features more easily.Scalable Applications : Docker makes it easier to scale applications horizontally and vertically. With Docker, it's easy to spin up additional containers to handle increased traffic or to scale up containers to handle more resource-intensive workloads.
What are the Components of Docker? Now that you know the importance of Docker, you must be wondering about its components and utilities that you'll find in this section. Docker has many components, which include:
Containers An essential component of Docker is its container. A container is a standard software unit that encapsulates code and all its dependencies so projects may operate fast and reliably across different environments while still being compatible with the host operating system. Creating numerous containers from a single image improves operational efficacy.
Moreover, a virtual machine (VM) abstracts the hardware, whereas a container virtualizes software at the operating system level by isolating the user space. All containers share the kernel of the host system. Since they are instantiated from images, containers do not persist between runs.
Docker Engine The open-source host software handles the construction and operation of containers. Containers may run on various server platforms, including Windows and Linux distributions, including Oracle Linux, CentOS, Debian, SUSE, and Ubuntu, all of which are supported by Docker Engines, which function as client-server applications.
Docker Daemon To build and maintain Docker images, the client communicates with the Docker daemon, a service. Simply put, the Docker daemon is the brains of your Docker operation. The Docker host is the server that hosts the Docker daemon.
Docker Images Collection of software meant to be executed as a container, including the necessary instructions for making a container compatible with the Docker platform. You must create a whole new image from scratch to modify an image.
Docker Registry A scalable and open-source solution called a "Docker registry" has been developed to store and share Docker images. The registry uses tags to keep tabs on different image revisions stored in different repositories. The git version control system is used to do this.
Docker File The foundation of every Docker container is a plain text file that details the steps necessary to create the Docker container image. DockerFile is a useful tool for automating the generation of Docker images. To create an image, Docker Engine executes a series of command-line interface (CLI) commands. Docker's command list is extensive, but all the commands follow the same pattern. Docker operations remain consistent across content types, infrastructure, and other conditions.
Docker Hub Docker Hub is the "world's biggest library and network for container images" and an open repository of Docker images. About 100,000 container images from thousands of companies, communities, and individuals are stored there. Docker, Inc.-created images, Docker Trusted Registry-verified images, and tens of thousands of more images are all included.
While using Docker Hub, image sharing is completely optional for all users. Users may also begin any containerization project by downloading preset basic images from the Docker registry.
