Last Week in Kubernetes Development

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Week Ending August 26, 2018

Community Meeting Summary

This week’s community meeting began with a demo of KeyCloak, an open-source Identity Access Management (IAM) tool for Kubernetes. Stian Thorgensen demonstrated using it for external authentication with Ingress; it can be used for token-based application auth, or for logging into Kubernetes itself.

SIG-Openstack’s Chris Hoge talked about their recent work: they created the external Cloud Provider plugin, added the Manilla Storage Provisioner for shared storage, and created a keystone authenticator, and wrote a lot of docs on how to use the Cloud Provider API. They decided to delay deprecation of the in-tree Openstack provider until 1.13 to give folks time to migrate. Other future work includes certifying Magnum, supporting autoscaling, and transitioning from a SIG to being a WG of SIG-Cloud-Provider.

Saad Ali of SIG-Storage presented on their work for 1.12. They will be moving topology-aware volume scheduling from cloud-provider-specific code to a generic API on top of CSI, meaning some of the provider-specific code is going away. Snapshot & restore support will be available in alpha, and CSI is going GA.

Matt Farina shared SIG-Apps’ current work, including: finishing the SIG-Apps charter, adding recommended labels for Helm apps, and have started work on an Application specification and API for CRD-based apps. For the Workloads API, development continues on Lifecycle Hooks, Pod disruption budget, and giving Jobs deterministic pod names. Work continues on the Kompose project. The Helm project has been moved out of SIG-Apps and into its own CNCF project and Github namespace, except for Charts, which stays where it is in order to take advantage of Prow automation.

Aaron Crickenberger offered an update on automation progress: all repos are in sigs.yaml and have the canonical list of Labels, and only one repo doesn’t have OWNERs. They are currently getting repos to use the same merge automation, and discussing /retest and /lifecycle stale. Deploying Tide for merges is ready, but on-hold until after 1.12 release.

Steering Committee elections have started, and nominations are open until Sept. 14th. You can now register for the Seattle Contributor Summit through your Kubecon registration, and the same goes for the Shanghai New Contributor Workshop and Doc Sprints.

Release Schedule

Next Deadline: Code Slush, August 28th

That’s right, Code Slush starts this week. It’s time to clean up and finalize your PRs, and if that feature you’re working on isn’t stable yet, punt it to 1.13. Code Freeze starts a week later. CI Signal is not looking good, so we need everyone focused on fixing bugs.

In order to simplify contributions, Release Lead Tim Pepper has proposed to remove several required labels, most notably status/approved-for-milestone, from PRs and issues during Code Freeze. This would reduce the number of required labels to four (sig/, kind/, milestone, and priority/critical-urgent) from seven for 1.11. This proposal should pass by lazy consensus Aug. 27th.

The 1.10.7 update was released last week, including multiple fixes for the Metadata Agent.

KEP of the Week

Tim AllClair shared KEP 0014, which proposes RuntimeClass, instead of having choice of runtime performed in a completely opaque way in the Kubelet. The idea is to support alternate runtimes like Katacontainers and GVisor, allowing users to chose desired runtime via Podspec. Short-term goals are a minimal implementation; future goals include Pod Overhead and abstract RuntimeClasses, like “sandbox.” Some steps have been merged, see below.

#58679: Support annotations for admission webhook

A new AuditAnnotations field in the admission webhook response struct allows setting arbitrary key/value pairs which get written to the audit log. This can be used to record data related to the webhook call for future debugging or analysis.

#66971: #50102 Task 2: Add UntilWithSync

A follow up to #66906 last week, this adds a new UntilWithSync method to avoid some common bugs when writing watches. This new kind of watch will survive timeouts, reconnects, and other conventional client-side errors. The downside is that the guarantees are not quite as strong as a basic Until call, mostly with respect to event ordering and duplication. If you want to write a long-lived watch, consider if UntilWithSync can do the job.

#67518: Add RuntimeHandler to the CRI RunPodSandboxRequest and #67737: Runtimeclass pod API

A double header, two parts of kubernetes/features#585 got merged this week. The first adds a handler configuration layer to the low-level CRI interface, allowing some configuration of the underlying container runtime from higher levels of the system. This is paired with adding a RuntimeClassName field to the PodSpec API. It’s not yet hooked up to anything, but eventually will let pods select specific container runtimes or configurations of a single runtime.

#67675: Pass files to golint one at a time

Rather than passing large ranges of files into golint, it will now pass files in one at a time. This should provide better output, as golint exits on the first fatal error in any file.

#66257 Kubelet creates and manages node leases

Per KEP 009, the SIG-Node folks have been working on ways to improve and reduce node status polling. The alpha-gated NodeLease system is the new mechanism; default leases are 40 seconds.

Other Merges

Deprecated

Version Updates

Graph of the Week

graph of github token requests per hour by various bots

This week’s graph shows the success the Test-Infra automation has had in managing our GitHub API Token usage. While moving from mungers to the polling-based Prow helped for a bit, what really made the difference was Cole Wagner’s ghproxy tool, a cache for GitHub tokens. You can see in this graph the difference between 1.10 end-of-Freeze and 1.11 end-of-freeze; before the proxy, we were at max token usage for two days, as opposed to just minutes at a time. More token usage graphs here and here.

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