The digital transformation of the industry is in full swing, and enterprises are turning to cloud native platform, which has led to a series of changes in architecture scheme, production mode, thinking mode, business model and so on. Gartner’s projections show that by 2025, more than 95% of digital transformation initiatives will be based on cloud-native platforms, compared to less than 40% in 2021.
At the same time, the cloud native technology represented by container is also continuously evolving, especially after Kubernetes becomes the technical core of cloud native system. Container technology has entered the Kubernetes era, the original technology system is quietly changing. Back in December 2020, Kubernetes announced that dockershim would be abandoned, and since then, the industry has been looking for alternatives to remove Dockershim.
After a year of transition, Kubernetes has announced that dockershim will be removed from Kubernetes version 1.24, which is scheduled for release around April this year. In this regard, SUSE Rancher as an open source enterprise Kubernetes management platform, has given a solution.
Live in related subjects (www.bilibili.com/video/BV1Xa… Rancher Greater China RESEARCH and development director Zhang Zhibo said, for users accustomed to using Docker, SUSE Rancher will continue to provide customers with Kubernetes+ Docker-related technology products; For those who want to follow Kubernetes upstream, SUSE Rancher offers Kubernetes+Containerd to help companies embrace containers and cloud native.
The rise of Kubernetes and the abandonment of Dockershim are inevitable for technological development
To understand why Kubernetes abandoned Dockershim, start with the evolution of container technology. Before the rise of container technology, the hottest technology in the industry was virtualization platforms, such as VMWare and OpenStack. Although the VIRTUAL machine can “virtual” many subsystems, but has a large space, slow startup, high resource consumption.
Container technology like Docker is lightweight “virtualization”. It does not need to “virtual” the entire operating system, but only needs to “virtual” a small-scale environment (similar to “sandbox”), so it successfully avoids the disadvantages of virtual machines and is warmly welcomed and sought after by the industry.
However, after Docker was open source in 2013, new problems emerged: Docker is just a tool for creating containers, an application container engine, not a container itself; If Docker is to be applied to specific business levels, it needs to be choreographed, managed and scheduled. In 2014, Kubernetes came out and used Docker as a container by default, realizing the arrangement, management and scheduling of containers.
Subsequently, Kubernetes code contains a lot of docker-related operation logic, in order to do decoupling, compatible with more container runtime, Kubernetes will operate Docker related logic out of the independent, formed dockershim. Therefore, Dockershim can be seen as a component of Kubernetes, whose main purpose is to manipulate Docker through CRI (Container runtime interface); In other words, Dockershim is equivalent to a transfer station or hub of Kubernetes and Docker.
As a result, the Dockershim code must be changed to support any functional changes in Kubernetes or Docker. However, the underlying runtime of Docker is Containerd, and containerd also supports CRI. Kubernetes can bypass dockershim and directly interact with ContainerD through CRI. In addition, as container technology evolved, container runtimes became so diverse that Kubernetes could interact with them via CRI that Dockershim became dispensable.
SUSE Rancher’s advice on how to deal with change
Kubernetes is ditching Dockershim, but that doesn’t mean Docker is obsolete. On the contrary, Docker, with its time-tested performance and more mature technology, not only has a large user base, but also is an important entry point for enterprises to carry out container technology applications for a long time.
In the opinion of Apache APISIX PMC Zhang Jintao, the reason why Docker’s development appears to be sluggish is related to the failure to find an appropriate commercialization route after open source. In the future, the core action of Docker is Kubernetes to provide developers with useful container technology, and its positioning is still container platform, rather than the underlying container runtime.
The future of containerd is going to be containerd’s world, zhang said, adding that moving away from Dockershim opens up new opportunities for containerd’s rapid adoption, which is evident in the 2021 CNCF Survey. Most users choose containerd over Docker. However, the underlying technology changes will not have much impact on enterprise users, and the public cloud and other commercial vendors as well as the open source community will have plenty of technology routes to mitigate the risks.
As Zhang jintao said, enterprises using cloud services are actually unaware of the container runtime switch. Even if the enterprise adopts the mode of self-built cloud rather than on-cloud hosting, end users do not need to pay attention to this, only the operation and maintenance personnel in the enterprise responsible for Kubernetes maintenance and management will care. Therefore, Zhang zhibo suggested that enterprises should respond to all changes with the same changes, and business stability should always be the first consideration, rather than the advancement of technical architecture.
Whether it’s the growth of Kubernetes, the decline of Docker, or containerd, companies don’t need to pay too much attention in the short term. For businesses built on public clouds, cloud vendors have helped enterprise customers solve the problem of upgrading the underlying technology architecture; Enterprise customers who build private clouds don’t have to disrupt the stability and durability of the traditional technology architecture. They just need to gradually replace and switch containerD as they build new clusters.
In the face of this technological change, SUSE Rancher adopted the Cri-Dockerd solution promoted by commercial vendors for the open source community to ensure that THE RKE cluster can continue to utilize Docker as its container runtime; For users who want to follow the upstream development and remove Docker, SUSE Rancher K3s/RKE2 and other open source products use Containerd as the default runtime. K3s can be used for local development and edge environments, while RKE2 can be used for data center scenarios.
That said, although SUSE Rancher is an open source vendor, it takes the commercialization of open source very seriously. While technology is trending in favor of Containerd, SUSE Rancher does not force customers to go to Docker, and if enterprise customers are still using Docker, SUSE Rancher will continue to maintain such programs.
Accelerate technology iteration, SUSE activate enterprise unlimited innovation potential
In the cloud native space, Kubernetes’ abandonment of Dockershim is a blip in the evolution of container technology; At present, the digital transformation of all industries continues to deepen, and enterprise customers are putting forward more and more new requirements for cloud computing technology.
According to the 2021 annual survey report released by CNCF, 96% of enterprises are using or evaluating Kubernetes, a record high since the survey was launched in 2016. CNCF believes that the de facto status of containers and Kubernetes has been consolidated, and with the development of technology, containers and Kubernetes will slowly shift to “behind-the-scenes” work; Enterprises seem to be using serverless and managed services more intensively than in the past, and developers don’t necessarily need to understand underlying container technologies.
Anticipating this trend, SUSE, the world’s largest independent open source company, completed the acquisition of Rancher Labs, the market leader in Kubernetes management, in 2020. As a result, it has comprehensive strength covering enterprise Linux, container, Kubernetes and edge computing, and can help enterprise customers innovate in data center, cloud, edge and other scenarios.
At the end of 2021, SUSE launched Harvester, an open source software called Hyperconverged Infrastructure (HCI) built by Kubernetes. Since then, SUSE’s product lineup has expanded to include hyperconverged infrastructure. Rancher Desktop 1.0.0 helps enterprise customers manage Kubernetes and containers as desktops on Mac, Windows, and Linux systems.
From container to Kubernetes, from enterprise Linux to edge computing, from open source to open, SUSE is on its way to a wider digital stardom than cloud computing.