Developing an application requires much more than writing tons of codes. With multiple frameworks, languages, architectures, and tools, each stage in the software development life cycle is a complex affair. But with a robust tool like Docker, the software development process becomes a cakewalk. Docker expedites and simplifies the workflow while giving developers ample scope for innovation. So, whether you’re an advanced-level software developer or a beginner about to start your Docker training journey, sound knowledge of Docker containers is a must.
In fact, Docker has the highest share in the global public and hosted container registry, leaving behind big players like IBM, AWS, and the like. So, let’s go on exploring more about Docker and some of the top Docker containers.
What is Docker?
Docker is an open-source platform for building, deploying, and running containerized applications. With Docker, you can easily isolate your applications from your infrastructure and accelerate software delivery. In addition, Docker methodologies facilitate quick shipping, testing, and deployment of code, thereby reducing the delay between writing codes and running them in production. Docker also refers to the Docker open-source project and Docker, Inc., the American technology company that designs and develops Docker-based productivity tools.
What is containerization?
Containerization refers to the encapsulation or packaging of software code and all its dependencies so that it can run with uniformity and consistency regardless of the infrastructure. Often used in concert with or as an alternative to conventional virtualization, containerization is a hot trend in software development that brings significant benefits to developers, operations teams, and the software infrastructure as a whole.
Why use containerization?
In traditional methods, bugs and errors creep in when the code developed in a particular computing environment is transferred to a new location. For instance, when you move a code from a Linux to Windows OS or from a desktop to a Virtual Machine (VM). Containers, however, eliminate this issue by packing the application code with libraries, related configuration files, and dependencies essential for its run. This container or software bundle is now isolated from the host OS and becomes a portable, standalone entity capable of running on any platform.
Docker and containerization
While it’s possible to create containers without Docker, the platform simplifies safe container building, deployment, and management. Docker essentially provides the toolkit and platform to manage the lifecycle of your containers through simple commands and automation through a single API. The containers are not just lightweight but self-sufficient; they contain all that’s needed to run the application. Hence, developers need not worry about what’s installed in the host. Containers are ideal for continuous integration and continuous delivery (CI/CD) pipelines and teams adopting DevOps and Agile practices.
Why use Docker?
In a nutshell, using Docker brings the following benefits:
- Automated container creation
- Fast and consistent delivery of applications
- Responsive deployment and scaling
- Greater resource efficiency
- Enhanced developer productivity
Top Docker Containers
Knowing about Docker containers is an essential aspect of Docker training. Docker Hub is Docker’s extensive public registry with over 100,000 container images for users to access. Docker images consist of the executable application source code, libraries, tools, and dependencies required for the code to run as a container.
So, let’s take a look at some of the most popular ones among the lot.
MySQL is a widely used, open-source relational database management system (RDBMS) and a popular web server solution. It ensures easy accessibility by storing and structuring data in a meaningful manner.
If you need to quickly set up a database with minimum resources, deploying MySQL in a container offers a fast and convenient solution for small and medium-scale apps. Rather than having a separate server for database hosting, deploying a MySQL database container is an efficient option. With Docker, apps can instantly access MySQL as long as Docker’s engine is installed. As a result, you get a portable and compact storage unit for your database. Plus, you can add additional information, segment datasets, or restrict the container to data relevant to the app.
PostgreSQL is another popular relational database tool with functionalities quite similar to MySQL. This advanced relational database system supports both JSON (non-relational) and SQL (relational) querying.
PostgreSQL has been the database of choice for web, mobile, and analytics applications. It is a widely-used Docker image run in containers. The reliability, stability, and data integrity of the object-relational database system is enhanced when run using Docker. Docker simplifies running PostgreSQL on different machines. Moreover, instead of having a single centralized database for several applications, developers can deploy a PostgreSQL container for every application.
MongoDB is an open-source, document-oriented NoSQL database for high-volume data storage. Unlike traditional relational databases that use rows and tables, MongoDB utilizes collections and documents.
MongoDB instances can be run using Docker. Users can create a portable and extensible NoSQL database by setting up MongoDB as a container. A containerized MongoDB instance has the same behavior as that of a non-containerized MongoDB instance regardless of the underlying configuration. Besides the storage and security benefits that any containerized database provides, MongoDB offers a dynamic and flexible database solution for the management of constantly changing vast amounts of data.
Jenkins is an open-source continuous integration and delivery server. It is a popular tool for the management and control of the software development process and accelerates the integration, deployment, and build automation throughout the entire software development lifecycle.
Running Jenkins as a Docker container has several advantages. First of all, all your Jenkins configuration files will live inside the container instead of the host machine. Hence, you can avoid your files from mixing up with Jenkins configuration files. Moreover, Docker instances are easily manageable if you want to run Jenkins on multiple platforms. Finally, creating and destroying the Jenkins server and removing all the Jenkins data is easier.
Container technology offers benefits that have simplified app development. With functionalities like application isolation, cost-effectiveness, and scalability, containers are no less than VMs. What’s more, containers have the added advantage of being lightweight while increasing developer productivity and promoting greater resource efficiency. Overall, containerization is a boon to developers, and Docker contributes by providing a platform for app containerization. Undoubtedly, container technology’s wide-scale adoption and usage make signing up for a Docker training course a wise investment for budding developers.