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If a ResourceSlice got published by the ResourceSlice controller in a DRA driver and then that ResourceSlice got deleted quickly (within one minute, the mutation cache TTL) by someone (for example, the kubelet because of a restart), then the controller did not react properly to the deletion unless some other event triggered the syncing of the pool. Found while adding upgrade/downgrade tests with a driver which keeps running across the upgrade/downgrade. The exact sequence leading to this were: - controller adds ResourceSlice, schedules a sync for one minute in the future (the TTL) - someone else deletes the ResourceSlice - add and delete events schedule another sync 30 seconds in the future (the delay), *overwriting* the other scheduled sync - sync runs once, finds deleted slices in the mutation cache, does not re-create them, and also does not run again One possible fix would be to set a resync period. But then work is done periodically, whether it's necessary or not. Another fix is to ensure that the TTL is shorter than the delay. Then when a sync occurs, all locally stored additional slices are expired. But that renders the whole storing of recently created slices in the cache pointless. So the fix used here is to keep track of when another sync has to run because of added slices. At the end of each sync, the next sync gets scheduled if (and only if) needed, until eventually syncing can stop.
Kubernetes (K8s)
Kubernetes, also known as K8s, is an open source system for managing containerized applications across multiple hosts. It provides basic mechanisms for the deployment, maintenance, and scaling of applications.
Kubernetes builds upon a decade and a half of experience at Google running production workloads at scale using a system called Borg, combined with best-of-breed ideas and practices from the community.
Kubernetes is hosted by the Cloud Native Computing Foundation (CNCF). If your company wants to help shape the evolution of technologies that are container-packaged, dynamically scheduled, and microservices-oriented, consider joining the CNCF. For details about who's involved and how Kubernetes plays a role, read the CNCF announcement.
To start using K8s
See our documentation on kubernetes.io.
Take a free course on Scalable Microservices with Kubernetes.
To use Kubernetes code as a library in other applications, see the list of published components.
Use of the k8s.io/kubernetes module or k8s.io/kubernetes/... packages as libraries is not supported.
To start developing K8s
The community repository hosts all information about building Kubernetes from source, how to contribute code and documentation, who to contact about what, etc.
If you want to build Kubernetes right away there are two options:
You have a working Go environment.
git clone https://github.com/kubernetes/kubernetes
cd kubernetes
make
You have a working Docker environment.
git clone https://github.com/kubernetes/kubernetes
cd kubernetes
make quick-release
For the full story, head over to the developer's documentation.
Support
If you need support, start with the troubleshooting guide, and work your way through the process that we've outlined.
That said, if you have questions, reach out to us one way or another.
Community Meetings
The Calendar has the list of all the meetings in the Kubernetes community in a single location.
Adopters
The User Case Studies website has real-world use cases of organizations across industries that are deploying/migrating to Kubernetes.
Governance
Kubernetes project is governed by a framework of principles, values, policies and processes to help our community and constituents towards our shared goals.
The Kubernetes Community is the launching point for learning about how we organize ourselves.
The Kubernetes Steering community repo is used by the Kubernetes Steering Committee, which oversees governance of the Kubernetes project.
Roadmap
The Kubernetes Enhancements repo provides information about Kubernetes releases, as well as feature tracking and backlogs.