Why Docker

While there are several container technologies, Docker is one of the most popular and commonly used technologies.

Introduction

When considering container technologies, Docker is by far the most well-known and popular container platform in use today. However, there are different platforms on the market, each with unique approaches and use cases. Even though all have a similar concept of images and containers, there are some technical differences worth noting.

As to why we have chosen containerization, see the page Why choose containerization technology.

Comparison of technologies

Docker

Docker is without a doubt the most popular container application/platform. According to Stack Overflow’s 2020 Developer Survey, which included almost 65,000 respondents, Docker was the third most popular platform among developers, trailing only Linux and Windows. In this survey, Docker was the most wanted and the second most loved platform.

Docker is incredible in many ways. It is a developer-friendly open source platform that can be used for rapid application development and is complemented by outstanding documentation, which is a major reason for its popularity.

Docker employs the client-server architecture, which entails clients requesting and receiving services from a host, in this case, the Docker daemon. Any contact with Docker may be initiated by the Docker client via an API call. The Docker client can communicate with many docker daemons. Any API queries performed by the Docker client are then received by the Docker daemon. The daemon is in charge of constructing, executing, and distributing your Docker containers and is responsible for the majority of the heavy work. This client-server architecture add one extra security layer to isolate the content inside the container from the outside environment.

Podman

Podman is an open-source, Linux-native tool designed to develop, manage, and run containers and pods under the Open Container Initiative (OCI) standards. Presented as a user-friendly container orchestrator developed by Red Hat.

Podman is a daemonless container engine that enables users to create, manage, and run OCI Containers on the Linux system. Podman, like Docker, is an open source project. The program’s source code is available to anyone. Podman, unlike Docker, does not require a daemon process to launch and manage containers. This is a significant distinction between the two projects.

The ability to run both root and rootless containers is also Podman’s main advantage. As a single point of failure, a daemon is not used. Compared to their root container counterparts, operating rootless containers is viewed by some as improving system security.

rkt

rkt, like other container technologies, lets you separate your software from its surroundings. However, rkt provides adjustable isolation, allowing you to choose the appropriate amount of isolation utilising rkt’s pluggable runtime architecture, which is divided into different phases.

rkt also includes security measures like a signature verification by default and even privilege separation, which is in charge of retrieving and validating signatures as unprivileged users. Having these characteristics can help to mitigate the potential damage caused by unforeseen vulnerabilities.

The rkt is not a complete platform, end-to-end solution. It is instead utilised in conjunction with other technologies or in substitute of particular Docker system components. Furthermore, the rkt project has been archived on GitHub as of February, 2020.

Hyper-V

Because each container can run its own kernel, Hyper-V containers are more closely aligned with the VM virtualization model. Because applications running within them do not need to be compatible with the host system, they are more portable than traditional containers. They also provide improved security due to greater isolation from the host operating system and other container environments. These advantages, however, come with a cost: Hyper-V containers have a slightly larger infrastructure footprint than Windows and other containers that rely on a shared kernel-based system.

The biggest disadvantage of the Hyper-V is that each guest environment must be based on Windows, though it might not have been the same version as the host.

Conclusion

After researching the container platform on the market, Docker still is the best option for Seedcase software. First of all, Docker has the world’s largest repository of container images that allow Docker users to create, test, store and distribute containers. Secondly, Docker is a single, robust, and autonomous tool. Docker manages, runs, builds, and does all other container-related tasks independently of any other third-party tools. Lastly, Docker has a lengthy history of working with well-known cloud platforms like Amazon Web Services (AWS) and Google Cloud Platform (GCP). It is also compatible with Microsoft, Azure, and OpenStack. Overall, regardless of how great the alternatives are, Docker is the most suitable container platform for this project.