This document summarizes an update on Kubernetes and the Container Storage Interface (CSI). It provides background on CSI and its benefits for vendors and users. It outlines new features in Kubernetes 1.13 and 1.14, including full CSI support and new alpha features. Future plans are discussed for Kubernetes 1.15 and beyond. The document encourages involvement in the Kubernetes SIG-Storage community.

1. Michelle Au
Software Engineer, Google
Kubernetes SIG-Storage
Kubernetes and
Container Storage
Interface Update

2. Agenda
Background on CSI
What’s New in Kubernetes?
Future
Getting Involved

3. Background

4. What is CSI?
Specification for orchestrating control plane operations on file and block storage
- https://github.com/container-storage-interface/spec
- Create and delete
- Attach and detach
- Mount and unmount
- Snapshot and restore
Industry standard supported by multiple container orchestrators
- Kubernetes
- Mesos
- Cloud Foundry

5. Vendor Benefits
Write one driver that works across multiple orchestrators
Develop outside of Kubernetes core
- Independent release cycle
- Could be closed source

6. Kubernetes Benefits
Vendor code does not need to be imported into core repository
Vendor code cannot crash core Kubernetes components
Core maintainers don’t need to review vendor code
- More time to develop core features!

7. End User Benefits
Large ecosystem of CSI drivers available
- https://kubernetes-csi.github.io/docs/drivers.html
- Over 35!
Get bug fixes and new features faster without upgrading your
Kubernetes cluster

8. Kubernetes Integration

9. apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: my-disk
spec:
storageClassName: fast-storage
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 100Gi
Kubernetes API
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: fast-storage
provisioner: csi-driver.example.com
parameters:
foo1: bar1
foo2: bar2

10. What’s New?

11. Kubernetes 1.13
Basic CSI support is GA
- Dynamic provisioning, attaching, mounting
- 1.0 spec added, 0.3 spec deprecated
Existing alpha features
- Snapshots
- Raw block
- Topology

12. Kubernetes 1.14
Features promoted to beta
- Raw block
- Topology
New alpha features
- Resizing
- Migration of in-tree plugins

13. Future

14. Kubernetes 1.15 and Beyond
New alpha features
- Ephemeral volumes
- Group snapshots
- Application snapshots
- Volume cloning
- Windows OS

15. Driver Management
New challenges:
- Versioning
- Backwards compatibility
- Upgrade/downgrade
Kubernetes distros can pre-package/manage qualified drivers

16. Getting Involved

17. Kubernetes SIG-Storage
Bi-weekly meetings
- https://github.com/kubernetes/community/tree/master/sig-storage
Slack
- #sig-storage on kubernetes.slack.com
Me
- Github/Slack: msau42
- Twitter: _msau42_

18. First Time Contributions
Improve test coverage
- Raw block
- Resizing
- Snapshots
- Topology
Fixing bugs
- Look for issues with “help wanted” label
- https://github.com/kubernetes-csi
- https://github.com/kubernetes/kubernetes
- Filter by label “sig/storage”

19. Questions?

20. [Extra]
Driver Deployment
Architecture

21. Deployment Architecture

22. [Extra]
Vendor Resources

23. Writing a CSI Plugin
Developer docs
- https://kubernetes-csi.github.io/docs/
Hostpath sample plugin
- https://github.com/kubernetes-csi/csi-driver-host-path
- Not for production!

24. CSI Spec Testing
Validate that your CSI plugin conforms to the CSI spec
- csi-sanity test suite
- https://github.com/kubernetes-csi/csi-test/tree/master/pkg/sanity

25. Kubernetes Testing
Run Kubernetes E2E tests against any CSI driver
- https://github.com/kubernetes/kubernetes/tree/master/test/e2e/
storage/external
- Prereq: K8s cluster with CSI driver already installed
- Future: CSI driver qualification/conformance