Dockershim is about to be removed? See how SUSE Rancher responds!

The digital transformation of the industry is in full swing, and enterprises are turning to cloud-native platforms in an all-round way, which has triggered a series of changes in architectural solutions, production methods, thinking models, and business models. Gartner predicts that by 2025, more than 95% of digital transformation initiatives will be based on cloud-native platforms, up from less than 40% in 2021.

At the same time, cloud-native technologies represented by containers are also evolving, especially after Kubernetes has become the technical core of the cloud-native system. Container technology has entered the Kubernetes era, and the original technology system is quietly changing. Back in December 2020, Kubernetes announced that dockershim would be deprecated, and since then, the industry has been looking for alternatives to remove dockershim.

After a transition over the past year, Kubernetes has announced that dockershim will be removed in Kubernetes version 1.24, which is scheduled to be released around April this year. In this regard, SUSE Rancher, as an open source enterprise-level Kubernetes management platform, has already given a way to deal with it.

In the recent live broadcast of related topics ( https://www.bilibili.com/video/BV1Xa411C78k?spm_id_from=333.999.0. ), Zhang Zhibo, R&D Director of SUSE Rancher Greater China, said that for users who are accustomed to using docker , SUSE Rancher will continue to provide customers with Kubernetes+Docker related technology products; for those users who want to follow the upstream development of Kubernetes, SUSE Rancher will help enterprises embrace containers and embrace cloud native by providing Kubernetes+Containerd related technology products.

Kubernetes rises, abandoning is inevitable for technological development1622ee0f21abbd

To figure out why Kubernetes deprecated dockershim, we must start with the development of container technology. Before the rise of container technology, the most popular technology in the industry was virtualization platforms, such as VMWare, OpenStack, etc. Although a virtual machine can "virtualize" many subsystems, there are problems such as large footprint, slow startup, and high resource consumption.

Container technologies such as Docker belong to lightweight "virtualization". It does not need to "virtualize" the entire operating system, but only needs to "virtualize" a small-scale environment (similar to a "sandbox"), thus successfully avoiding the The shortcomings of virtual machines are warmly welcomed and sought after by the industry.

However, after Docker was open sourced in 2013, new problems emerged: Docker is only a tool for creating containers, it is an application container engine, and it is not a container itself; if you want to apply Docker to a specific business level, you also need to orchestrate it , management and scheduling. In 2014, Kubernetes was born and used Docker as a container by default, realizing the orchestration, management and scheduling of containers.

Subsequently, the Kubernetes code contains a lot of Docker-related operation logic. In order to be able to decouple and be compatible with more container runtimes, Kubernetes separates the relevant logic for operating Docker and forms a dockershim. Therefore, dockershim can be regarded as a component of Kubernetes, the main purpose is to operate Docker through CRI (Container Runtime Interface); that is to say, dockershim is equivalent to a transfer station or hub between Kubernetes and Docker.

In this way, any functional change in Kubernetes or Docker, the dockershim code must be changed to support the change. However, the underlying runtime of Docker is containerd, and containerd also supports CRI. Kubernetes can bypass dockershim, a transit station, and directly interact with containerd through CRI; in addition, with the evolution of container technology, container runtimes have also become various Variety, Kubernetes can interact with them through CRI, so dockershim becomes dispensable.

the face of change, SUSE Rancher's advice and

Although Kubernetes is about to deprecate dockershim, this does not mean that Docker is outdated; on the contrary, Docker has proven performance and more mature technology. It not only has a large user group, but also has a long history of enterprises developing container technology. An important entry point for the application.

According to Zhang Jintao of Apache APISIX PMC, the reason why Docker's development is showing signs of fatigue is related to the fact that it has not found a suitable commercialization route since it was open sourced. In the future, the core action of Docker is that Kubernetes provides developers with easy-to-use container technology. Its positioning is still the container platform, not the underlying container runtime.

The future container runtime will be the world of containerd. Zhang Zhibo believes that the abandonment of dockershim has brought new opportunities for the rapid popularization of containerd. This is clearly demonstrated in the 2021 CNCF Survey. Most users choose containerd. Alternative to Docker. However, changes in the underlying technology will not have much impact on enterprise users. Public cloud and other commercial vendors and open source communities will have enough technical routes to avoid risks.

As Zhang Jintao said, enterprises using cloud services are actually unaware of the switching of container runtimes. Even if the enterprise adopts the mode of self-built cloud instead of hosting on the cloud, end users do not need to pay attention to this, only the operation and maintenance personnel responsible for Kubernetes maintenance and management in the enterprise will care. Therefore, Zhang Zhibo suggested that enterprises should respond to changes with the same constant, and business stability is always the first consideration, not the advanced nature of technical architecture.

Whether it is the rapid development of Kubernetes, the decline of Docker, or the general trend of containerd, enterprises do not need to pay too much attention in the short term. For those businesses built on public clouds, cloud vendors have helped enterprise customers solve the problem of upgrading the underlying technical architecture; and for enterprise customers who have built private clouds, they do not have to destroy the stability and durability of traditional technical architectures , you only need to gradually complete the gradual replacement and switching of containerd when establishing a new cluster.

Faced with this technological change, SUSE Rancher adopts the cri-dockerd solution promoted by commercial manufacturers for the open source community to ensure that RKE clusters can continue to use Docker as their container runtime; and for users who want to follow upstream development and remove Docker, SUSE Rancher's 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 in data center scenarios.

That is to say, although SUSE Rancher is an open source vendor, it attaches great importance to the commercialization of open source. Although the development of technology tends to containerd, SUSE Rancher will not force customers to use Docker. If enterprise customers are still using Docker, SUSE Rancher will continue to maintain such projects.

Accelerates technology iteration, SUSE activates unlimited innovation potential

In the cloud-native field, the abandonment of Dockershim by Kubernetes is only a small episode in the evolution of container technology; at present, the digital transformation of various industries continues to deepen, and enterprise customers are putting forward more and more new requirements for cloud computing technology.

A few days ago, the CNCF released its 2021 annual survey report, showing that 96% of enterprises are using or evaluating Kubernetes, which is an all-time high since the survey began in 2016. The CNCF believes that the de facto status of containers and Kubernetes has been solidified, and as the technology evolves, containers and Kubernetes will slowly move to work "behind the scenes"; enterprises appear to be using serverless and managed services more intensively than in the past, and developers are also Knowledge of the underlying container technology is not necessarily required.

In anticipation of 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, thus enabling comprehensive coverage of enterprise-grade Linux, containers, Kubernetes and edge computing The comprehensive strength in such fields can help enterprise customers innovate in any scenario such as data center, cloud, and edge.

At the end of 2021, SUSE's hyper-converged infrastructure (HCI) open source software Harvester built through Kubernetes officially GA . Since then, SUSE's product lineup has expanded to the field of hyper-converged infrastructure. Not long ago, SUSE officially released the container desktop management tool Rancher Desktop 1.0.0 , which can help enterprise customers manage Kubernetes and containers in desktop form on Mac, Windows and Linux systems.

From containers to Kubernetes, from enterprise-level Linux to edge computing, from open source to open, SUSE is moving towards a sea of digital stars that is wider than cloud computing.