Docker is a popular tool that is used to create, deploy, and run apps by using containers. Developers make use of docker containers to package applications using libraries and other dependencies. Docker makes the packaging process easier and lets developers ship their apps as a single package. The biggest reason for driving Docker’s popularity is that developers do not have to worry about compatibility. Applications built using Docker will run on any compatible OS regardless of custom settings deployed by users.
Docker essentially works like a virtual machine but it does not create a separate virtual operating system. Instead, it allows apps to make use of the same kernel as the user system. Developers need to ship their apps with only the dependencies not available on the host computer, which helps bring down the application sizes and also improves performance. Most importantly, just like Django web application Docker is an open source application and any developer can contribute to Docker and build features that may benefit their applications.
A] How Does Docker Work?
Docker allows developers to package and run apps in “containers”, but how does it work? Docker is capable of running multiple containers at the same time on a host computer. Since containers do not stress CPU resources too much, multiple instances can run at the same time. The need for a hypervisor is also eliminated in the process by making use of the host’s machine kernel.
Docker is so well-optimized that its containers can run within virtual host machines as well. The platform is capable of offering tools to manage the lifecycle of an app’s containers. Complete development is possible through the use of containers and all supporting components can be directly built into one package as well.
Once an app is developed, it becomes the unit for testing and distribution of applications. Once apps are ready to be shipped, developers can deploy their applications into the production environment as an orchestrated service or as a container. The apps will work within a local data center, a cloud provider as well as a hybrid solution of both options making it a highly flexible tool for development.
Docker has its own engine which is a client-server application that includes three major components – a server, a command-line interface, and a REST API.
- The Server is a daemon process which is a long-running program and it handles all Docker operations. The daemon is responsible for creating and managing Docker objects such as networks, volumes, containers, and images.
- Docker’s CLI (command-line interface) controls and interacts with the Docker daemon via scripts and direct commands.
- The REST API is responsible for specifying interfaces that programs can use to communicate with the daemon and send instructions.
B] What Are Docker Containers?
Typically, a dockers container contains system tools, libraries, settings, code, and runtime. Containers are available for both Windows and Linux systems. Containers isolate the software from its environment to ensure staging and development work properly.
Docker created the industry standard to enable applications to become portable and usable across multiple systems regardless of configuration and settings. Containers share system kernels and do not require operating systems per application. They enable high-efficiency, which, in turn, reduces the costs involved with server upkeep or licensing. Containers also offer a secure environment and the best possible isolation in the development industry.
C] Advantages of Docker Containers
Docker adoption has been picking up in the industry and for good reason. Here are the top advantages of using Docker that are driving impressive growth.
1. Cost Efficiency
The biggest advantage of Docker containers is the amount of cost-saving it offers. The return on investment when using Docker is very lucrative and it helps developers drive down costs while also improving profits. Docker is more lucrative for larger companies that want to generate solid revenue over a long period of time.
Docker facilitates long-term savings by reducing the amount of infrastructure and resources needed for development. The biggest difference in investment is visible when it comes to server costs. Using such efficient applications also requires fewer engineers to develop and manage them as well, which leads to lower human resource costs.
2. Productivity
Docker containers ensure multiple development and release cycles are handled consistently under a single unified platform. Having a standardized environment allows production to be as efficient as possible.
A standardized service infrastructure across an organization allows team members to work in an environment where developers are on par with each other. All engineers are automatically equipped to fix bugs and analyze the performance of their applications. It drastically reduces the amount of time that is wasted on bug fixing and improving features and allows more time to be invested in feature development.
Docker makes version changes very easy through its modular infrastructure. If an upgrade to a component causes issues with your application, you can simply roll back an upgrade for the problematic component. Docker lets users roll back to a previous image of a component and also allows developers to replicate images for testing purposes. Launching saved Docker images are on par with running machine processes and performance is never a concern.
3. Compatibility
Even if multiple users run an app on different systems and settings, apps developed using Docker run the same on all servers. Developers save a lot of time they would otherwise be spending on creating new environments and debugging issues specific to a particular environment. The codebase is easy to set up and is far more portable than any other platform.
Production infrastructure also becomes easier to maintain and far more reliable than using traditional development frameworks. The same container image can be used across all stages of app development. Developers can run these images separately without any dependency and speed up the development process.
4. Easier Deployment
Deployments in Docker take only a few seconds. With the platform creating containers for each individual process, it allows developers to save on boot time. Docker apps also do not boot into an OS and simply make use of the OS kernel instead. The apps can also write, erase, and rewrite data without losing efficiency.
5. Continuous Testing
Docker enables developers to test their apps in consistent environments right from the early development stages until the end of production. All Docker containers can be pre-configured to account for all possible dependencies and configurations. Developers can make use of the same containers until the production stages without needing any manual intervention.
If developers want to upgrade an app during the release cycle, changes can be made directly to the Docker containers. Even in the release cycle, developers can test new features and implement changes by simply modifying existing containers instead of building from scratch. The flexibility that Docker offers is what makes the platform so flexible.
Developers can test and release images across a number of servers at the same time. Security patches can be deployed in a similar fashion. All developers need to do is apply the required patches, test for issues and release it to the production stage by modifying containers.
6. Security
Other than the sheer amount of scalability and flexibility Docker brings to the table, its security is an important backbone. Docker automatically ensures that any app running within containers are fully segregated from each other.
Developers have complete control over how traffic is managed by the apps. One Docker container cannot access or process data of another container by default. Containers have access to individual resources that they can make use of including network stacks and dependencies.
7. Isolated Environment
Docker isolates and segregates your apps and its resources. The platform ensures that each container has access to all the resources that it needs. Developers can implement multiple containers for separate apps and run them as individual stacks. You can also delete apps by removing its container and there will be no temporary files of configuration settings left behind in the OS. Most importantly, Docker apps only make use of the resources that have been allotted to them instead of getting complete access. This fully isolates the apps and offers unmatched security.
8. Cloud Technology
One of the primary advantages of docker is its portability. Enterprises over the years have been shifting towards cloud-based computing. Most popular cloud platforms like AWS and GCP have already adopted Docker’s extensive support. Developers can run containers within cloud-based platforms. Cloud-based environments also allow apps to be moved from one cloud service to another with ease.
Microsoft, Google, Amazon, and other tech giants have moved on to cloud-based infrastructure and all of them support Docker’s container system with just as much stability and consistency as end-user desktops.
D] Why Is Docker So Popular and Why the Rise of Containers?
Everyone has heard of Docker containers, but very few have been able to accurately justify its popularity. Before going deep into the platform’s popularity, one should note that there are other container platforms out there as well. Docker was neither the pioneer of container platforms nor is it the latest in the industry.
Microsoft, Google, Amazon, and other tech giants have moved on to cloud-based infrastructure and all of them support Docker’s container system with just as much stability and consistency as end-user desktops.
1. Open Source
Docker released in 2013 and it is still a very young technology when we compare it to other enterprise technologies that we have been using for more than a decade. Docker has always been open source which has attracted developers in the industry right from the start. Experts also state that if Docker launched in the late 2000s, its popularity would not have been what it is today.
The enterprises were far less interested in open source technology than it is today. They were simply looking for faster means of deploying apps and did not care if a platform was open source or not. Since the early 2010s, this mindset changed and Docker’s release in 2013 helped the platform cement itself.
2. The Fall of Virtual Machines
More importantly, during the early 2010s, virtual machines started falling out of favour in the software industry. Traditional virtualization options were available but they were not appealing enough to be picked up. The launch of Docker coincided with the DevOps revolution and the rest became history. For those unfamiliar with the DevOps revolution, it was a period in the early 2010s that saw a shift in the software industry. Developers started focusing on scalability and flexibility. Docker fit the bill perfectly and it helps developers build and deploy apps based on the prescripts set by DevOps.
Containers start and stop faster than any virtual machine can. They are also portable and are used in stable host environments. Moreover, it is much easier to scale containerized apps as code changes can be made very efficiently. Developers preferred using containers as it is very easy to break down complex apps into smaller modules and work on them.
3. Mirroring the Success Of Linux
Linux kernels started gaining popularity in the 1990s. What was once treated like a niche software project that was nothing but a pipe dream of a Finnish student, ended up becoming one of the most successful open-source operating systems of all time? Docker has a similar background and it shares its success story most likely mirrors that of Linux. Just like how Linux was obscure, Docker was nowhere near as pronounced as its competitors like LXC. Yet, the features it offered and its open source nature contributed greatly towards its success.
Docker’s success is driven by its impeccable launch timing that allowed the industry to resolve its software deployment and delivery problems at once. The five years before Docker’s launch, developers were brainstorming ideas to address these issues but were unsuccessful at doing so. Older container frameworks did offer similar solutions but failed to grab the attention of developers as the industry was not concerned about flexibility and scalability as much in the 2000s.
Just like how Linux’s success was driven by its competition being in disarray, Docker achieved similar success by offering an innovative approach to development. A decentralized development strategy was welcomed by the industry with open arms and it led to Docker being the undisputed champion for container-based development.
#Conclusion
This sums up what is Docker, how it works, and the advantages of Docker containers. Docker is one of the best tools for development in the industry today, and its popularity is growing significantly. It is best suited for larger companies, and being open source, it is a flexible platform that can be used for the development of varied applications.