contributing KEPs in SIG Node: best practices

sig-node/CONTRIBUTING.md

@@ -2,24 +2,138 @@
 
 Welcome!
 
-## For Kubernetes Contributions
+Thank you for your interest in contributing to SIG Node. SIG Node is one of the
+biggest SIGs in Kubernetes. Reliability and performance of millions of nodes
+running critical applications in production rely on the quality of your
+contribution(s). The diversity of workloads, environments, and the scale SIG
+Node needs to support makes every code change risky as all the side effects need
+to be evaluated.
+
+Please make sure you understand and are up to the challenge. The contributing
+instructions are designed to help you.
+
+## For Kubernetes Code Contributions
 
 Read the [Kubernetes Contributor Guide](https://github.com/kubernetes/community/tree/master/contributors/guide#contributor-guide).
 
 If you aspire to grow scope in the SIG, please review the [SIG Node contributor ladder](./sig-node-contributor-ladder.md) for SIG specific guidance.
 
 ### For Enhancements
 
-SIG Node enhancements are available in the <https://github.com/kubernetes/enhancements/tree/master/keps/sig-node>.
-
-#### Helpful Links for Sig-Node
+Find out if [your thing is an enhancement a.k.a KEP](https://github.com/kubernetes/enhancements/?tab=readme-ov-file#is-my-thing-an-enhancement).
+A good way to do that is to open and issue and get feedback from SIG Node
+reviewers and approvers. You can present your idea at a weekly
+sig-node meeting to get interactive and more immediate feedback.
+
+If you plan to contribute an enhancement, please prepare yourself for at least 1
+year of engagement. A KEP takes at least 4 kubernetes releases to move from
+alpha to beta to GA. If there are API / kubelet skew considerations, it may take
+even longer. SIG Node expects that contributors commit to taking a KEP to GA stage to avoid
+[permanent betas](https://kubernetes.io/blog/2020/08/21/moving-forward-from-beta/#avoiding-permanent-beta).
+It is always surprising how much work is needed to productize the feature after
+it seems complete - addressing edge cases, comprehensive testing, and documentation
+take a lot of effort.
+
+If you are not ready for this commitment, you can consider teaming up with other
+contributors in the community or contribute to a KEP driven by somebody else.
+
+SIG Node enhancements are available:
+
+- Committed KEPs [directory](https://github.com/kubernetes/enhancements/tree/master/keps/sig-node)
+- All open KEPs [tracking issues](https://github.com/kubernetes/enhancements/issues?q=is%3Aissue+is%3Aopen+label%3Asig%2Fnode+)
+
+Here are some best practices how to approach KEP development:
+It is based on a [talk](https://kcsna2023.sched.com/event/1Sp9i/implementing-a-big-feature-on-an-example-of-a-sidecar-container-kep) 
+*"Implementing a big feature on an example of a Sidecar container KEP"*
+([Recording](https://www.youtube.com/watch?v=c3iV8E8EDUA), [Slides](https://static.sched.com/hosted_files/kcsna2023/a0/KCS-NA-2023-ppt.pdf)).
+
+#### Before Starting
+
+- **Prove the need**: Clearly articulate the problem the KEP addresses, identify
+  the target audience, and demonstrate the community-wide benefits.  
+- **Secure sponsorship and reviews**: Find sponsors, reviewers, and approvers
+  early in the process to ensure alignment and avoid delays.  
+- **Show commitment**: Demonstrate dedication to the KEP's success by actively
+  working on its implementation and ensuring code quality.  
+- **Manage expectations**: The KEP process takes time, anticipate at least two
+  releases for beta and four for GA.
+
+At this stage the expectation is that the proposal is written in general-enough
+terms as a Google Doc for easy commenting and fast collaborative editing.
+Sharing the design document with `[email protected]` for commenting and with SIG
+members `[email protected]` for commenting or in some cases
+editing is a good practice.
+
+It is also very helpful to attend SIG Node weekly meeting to present your
+proposal. Most of the time meeting agenda is open to discuss any proposals.
+During the meeting you can gather initial feedback, find collaborators, and
+secure sponsorship.
+
+#### API Design
+
+- **Define use cases and scope**: Enumerate specific use cases and define the
+  problem's boundaries to avoid scope creep.  
+- **Consider the bigger picture**: Illustrate how the KEP fits into the existing
+  Kubernetes design and how it will handle future requests.  
+- **Document decisions**: Record all design decisions, including pros, cons, and
+  responsible individuals.  
+- **Address potential misuse**: Anticipate potential abuse or misuse scenarios
+  and design the API to mitigate them.  
+- **Engage reviewers**: Utilize SIG experts for API pre-reviews and PRR
+  pre-reviews to gain support and streamline the review process.
+
+Kubernetes API is a main interface many users experience Kubernetes. API
+approvers are often the most experienced community members, who can help ensure
+the feature fit Kubernetes best practices, will not break compatibility, and
+will fit nicely with other Kubernetes capabilities. Even if use cases were
+approved by SIG Node approvers, API approvers may reject the proposal and ask to
+redesign it.
+
+Some KEPs may go back and forth between use cases and API design for many
+iterations. This often happens when use cases are not described completely or a
+lot of context is lost in written feedback. If the KEP is going in those
+circles, the recommendation is to request a meeting between SIG Approvers and
+API approvers driven by KEP author. It may be a dedicated meeting or an invite
+of API approvers to SIG Node weekly meeting or SIG Node approvers to API
+meeting.
+
+Once API approval was received, SIG Node approvers will review it again as SIG
+always has the last word in the feature design.
+
+Note, SIG approvers may request sign offs from other SIGs like Security,
+Instrumentation, Storage, Networking, Windows, etc. The process of getting
+approval is generally the same.
+
+#### Implementation
+
+- **Structure the implementation**: Divide the implementation into
+  pre-factoring, minimal complete product, and post-API changes for better
+  organization and review.  
+- **Isolate feature gate logic**: Ensure the mainline code remains unaffected
+  when the feature gate is disabled.  
+- **Adapt and adjust**: Be prepared to modify the KEP's scope or features based
+  on implementation challenges.  
+- **Collaborate effectively**: Maintain communication through group chats or
+  meetings and consider using a shared branch for better coordination.  
+- **Improve the codebase**: Leave the code in a better state than you found it
+  to facilitate future maintenance and enhance your credibility.
+
+By adhering to these best practices, you can increase the chances of your KEP
+being successfully implemented and accepted.
+
+Sometimes SIG may over-commit on KEPs for the release. And if two big KEPs
+touching the same code path, SIG may decide to only take one KEP for a release.
+Even if this is the case, properly structured KEP implementation will ensure
+that some progress was made for that release.
+
+### Helpful Links for SIG Node
 
 **Code**:  
 
-For general code organization, read [contributors/devel/README.md](../contributors/devel/README.md) for explaining things like
+For general code organization, read [contributors/devel/README.md](../contributors/devel/README.md) to learn about things like
 `vendor/`, `staging`, etc.
 
-* Kubelet
+* kubelet
   * <https://github.com/kubernetes/kubernetes/tree/master/cmd/kubelet>
   * <https://github.com/kubernetes/kubernetes/tree/master/pkg/kubelet>
 * Probe: <https://github.com/kubernetes/kubernetes/tree/master/pkg/probe>