AWS CDK RFCs

This repo is a place to propose and track major upcoming changes to AWS CDK, jsii, and other related projects. It also is a great place to learn about the current and future state of the libraries and to discover projects for contribution.

Jump to: What is an RFC? | When to submit? | RFC Process | RFC Life Cycle

#	Title	Owner	Status
79	CDK v2.0	@RomainMuller	👷 implementing
192	Removal of the "constructs" compatibility layer (v2.0)	@eladb	👷 implementing
193	Fixing of type unions	@RomainMuller	⏰ final comments
18	Open context provider framework	@ddneilson	✍️ review
175	AppSync Mapping Template Object Model	@MrArnoldPalmer	✍️ review
204	Go language bindings		✍️ review
249	V2 Experiments	@ericzbeard	✍️ review
1	CDK Watch		💡 proposed
2	Migration Paths		💡 proposed
3	Integrate CLI into Native Modules		💡 proposed
4	CDK Testing Toolkit	@nija-at	💡 proposed
5	Security-restricted environments		💡 proposed
7	Lambda Bundles		💡 proposed
8	Project structure guidelines		💡 proposed
9	Master developer guide sources in main repo		💡 proposed
10	New workshop modules		💡 proposed
13	Improvements to Reference docs		💡 proposed
14	Toolchain 2.0	@shivlaks	💡 proposed
15	Scaffolding		💡 proposed
17	CLI support for multiple-environments		💡 proposed
19	Introspection API		💡 proposed
20	Security posture summary		💡 proposed
21	CDK Explorer Roadmap		💡 proposed
22	Cost calculator		💡 proposed
23	Stateful resource support		💡 proposed
24	Resource imports		💡 proposed
25	Defaults & configuration policy		💡 proposed
26	Monitoring packs		💡 proposed
27	200 resource limit tools & guidance		💡 proposed
30	Improve synthesized template output		💡 proposed
31	Integration tests		💡 proposed
32	App-centric operational experience		💡 proposed
34	Third-party construct ecosystem		💡 proposed
35	Publish construct library guidelines		💡 proposed
39	Release public artifacts (lambda layers for custom resources, docker images)		💡 proposed
40	Stack traces across language boundaries		💡 proposed
48	Faster builds	@rix0rrr	💡 proposed
51	Standardize security groups		💡 proposed
52	Support resource import		💡 proposed
58	Improved ergonomics for stack default environment		💡 proposed
63	CDK in Secure Environments		💡 proposed
64	Garbage Collection for Assets		💡 proposed
65	CDK Code Generation from AWS Console		💡 proposed
66	StackSets Support		💡 proposed
67	Monitoring Packs		💡 proposed
69	One-off "job" Stacks ("auto destruct")		💡 proposed
70	Cost Estimation Tools		💡 proposed
71	Triggers		💡 proposed
72	Stack Policy		💡 proposed
73	AWS Resource Model		💡 proposed
74	Common API for Resources with Web Addresses		💡 proposed
77	On-demand import of CloudFormation Resources from Registry		💡 proposed
78	Feature proposal: Workspaces		💡 proposed
82	Weak references		💡 proposed
83	Global Name Prefix		💡 proposed
86	AWS Account Alias Resource		💡 proposed
116	Easier identification of experimental modules	@rix0rrr	💡 proposed
118	New CDK Major Version		💡 proposed
127	CDK to directly reference/import/update an existing stack		💡 proposed
139	"fromLookup" for additional resources		💡 proposed
159	Cross-App Resource Sharing		💡 proposed
161	Cross-Region/Account References		💡 proposed
180	CustomResources: Allow usage across accounts		💡 proposed
201	Construct scope relocation		💡 proposed
217	Alternative Infrastructure Providers		💡 proposed
219	ECS Patterns Service Builder		💡 proposed
242	Bootstrap stacks as CDK apps		💡 proposed
244	Migration path for EKS Developer Preview		💡 proposed
247	CDK Common Stored Data Type Model		💡 proposed
248	Standardized context key for "cheap mode"		💡 proposed
253	CDK Metadata v2		💡 proposed
256	ReactCDK: Add JSX/TSX Support		💡 proposed
264	Generating L1s from CloudFormation Registry Schema Format		💡 proposed
6	Monolithic Packaging	@RomainMuller	✅ done
16	RFC Process	@MrArnoldPalmer	✅ done
36	Constructs Programming Model	@eladb	✅ done
37	Release from a "release" branch	@MrArnoldPalmer	✅ done
55	Feature Flags	@eladb	✅ done
92	CI/CD Asset Publishing	@rix0rrr	✅ done
95	Cognito Construct Library	@nija-at	✅ done
107	Publish a Construct Library Module Lifecycle document	@ccfife	✅ done
110	CLI Compatibility Strategy	@iliapolo	✅ done
171	CloudFront Module Redesign	@njlynch	✅ done
60	Bazel Build System		👎 rejected
164	Construct Library Segments	@nija-at	👎 rejected
81	AWS Landing Zone CDK pattern request		❓unknown
85	Cross Account resource import and source account tracking	@skinny85	❓unknown
158	Experiment with Resource Provider in TypeScript		❓unknown
162	Simplify working with logical IDs when refactoring CDK code		❓unknown
223	Better experience when developing lambda functions in the cdk		❓unknown
226	Context provider for cross-account CFN stack outputs		❓unknown
227	Integrate AWS CloudFormation StackSets for AWS Organizations as part of cdk deploy		❓unknown
228	Support for app.postDeploy() for post-deploy functions		❓unknown
229	Construct library pattern for metrics		❓unknown
230	Construct library pattern for grants		❓unknown
231	Construct library pattern for resources that use a VPC		❓unknown
232	Construct library pattern for resources that need IAM roles		❓unknown
233	Using Custom Types with CDK		❓unknown
246	[lambda] Package Docker asset as a lambda layer		❓unknown

What is an RFC?

An RFC is a document that proposes and details a change or addition to the CDK, jsii, and other related tooling. It also is a process for reviewing and discussing the proposal and tracking its implementation. "Request for Comments" means a request for discussion and oversight about the future of the CDK and jsii from contributors and users. It is an open forum for suggestions, questions, and feedback.

The process is intended to be as lightweight and reasonable as possible for the present circumstances. As usual, we are trying to let the process be driven by consensus and community norms, not impose more structure than necessary.

The RFC process itself is subject to changes as dictated by the core team and the community. Proposals can include proposed changes to the RFC process itself to better serve contributors.

When to submit an RFC?

You should consider using this process if you intend to make "substantial" changes to AWS CDK, jsii, or related tools. Some examples that would benefit from an RFC are:

• Any change to existing APIs that could break existing code.
• The removal of existing features or public APIs.
• The introduction of new idiomatic usage or conventions, even if they do not include code changes to CDK or jsii themselves.
• Changes to the documented contribution workflow.
• Features that cross multiple construct libraries.
• Additions or changes to framework capabilities.
• Additions or changes to formal specifications like cloud assembly, tree.json, jsii, etc.

The RFC process is a great opportunity to get more eyeballs on your proposal before it becomes a part of a released version of CDK/jsii. Quite often, even proposals that seem "obvious" can be significantly improved once a wider group of interested people have a chance to weigh in.

The RFC process can also be helpful to encourage discussions about a proposed feature as it is being designed, and incorporate important constraints into the design while it's easier to change, before the design has been fully implemented.

If you submit a pull request to implement a new major feature without going through the RFC process, it may be closed with a polite request to submit an RFC first.

Some changes do not require an RFC:

• Bugfixes for known issues.
• Additions only likely to be noticed by other developers of CDK/jsii, invisible to users of CDK/jsii.
• Additions of missing L1 or L2 constructs. Unless the service and/or constructs are especially complex or intentionally diverge from existing api design best practices.

If you're not sure whether your change requires an RFC, feel free to create an issue and ask.

RFC Process

In short, to get a major feature added to CDK/jsii, one usually writes an RFC as a markdown file and gets it approved and merged into the RFC repo. At that point the RFC is 'approved' and may be implemented into CDK/jsii.

1. Create a tracking issue for the proposed feature if one doesn't already exist. Use the tracking issue template as a guide. If a tracking issue already exists, make sure to update it and assign it to let others know you're working on a proposal.
2. Fork the RFC repo.
3. Copy 0000-template.md to text/<rfc#>-<my-feature>.md where <rfc#> is the tracking issue number and <my-feature> is the rfc title.
4. Fill in the RFC. Put care into the details: We welcome all honest efforts to contribute..
5. Submit a pull request with the title RFC: ### <title> where ### is the tracking issue number and title is the name of the proposal. As a pull request the RFC will receive design feedback from the core team and the larger community, and the author should be prepared to make revisions in response.
6. Update the tracking issue with a link to the RFC PR.
7. Advertise your RFC amongst stakeholders via social channels (e.g. twitter) and your team. Build consensus and integrate feedback. RFCs that have broad support are much more likely to make progress than those that don't receive any comments.
8. Eventually, the team will decide whether the RFC is a candidate for inclusion in CDK/jsii.
9. RFCs that are candidates for inclusion in CDK/jsii will enter a "final comment period" lasting 3 calendar days. The beginning of this period will be signaled by a team member adding a comment and label on the RFCs pull request.
10. An RFC can be modified based upon feedback from the team and community. Significant modifications may trigger a new final comment period. An RFC can also be modified after it has been merged and approved, in which case a new PR will be submitted with the modification, like any other code.
11. An RFC may be rejected by the team after public discussion has settled and comments have been made summarizing the rationale for rejection. A member of the team will then close the PR and issue.
12. An RFC may be accepted at the close of its final comment period. A team member will merge the RFCs associated pull request, at which point the RFC will become 'approved'.
13. At some point, someone will pick up the RFC for implementation. For major features this usually requires devising a detailed implementation plan. To that end, submit an additional PR on the RFC doc that either fills in the "Implementation Plan" section or references a separate document or GitHub Project Board which includes the plan.
14. Once this PR is approved, the RFC will move to the 'implementing' state. Usually we track implementation using GitHub projects.
15. Once implementation is complete, the RFC moves to 'done', and it's issue is closed.

If the submitter is someone from our CDK community (i.e., not core team member), a core team member will be assigned to 'shepherd' each proposal. They will generally be the ones updating the RFCs state in the tracking issue as it moves through the process. They can decide when a final comment period is triggered.

On the other hand, if the submitter is a core team member, they will identify another core team member, with consent, as their 'shepherd'. The shepherd would be the first contact for brainstorming, process and reviews. The core team would defer to the shepherd to do the first few rounds of reviews, after which the rest of the team should be engaged.

RFC Life Cycle

1. Proposed - A tracking issue has been created with a basic outline of the proposal.
2. Review - An RFC document has been written with a detailed design and a PR is under review. At this point the PR will be assigned a shepherd from the core team.
3. Final Comment Period - The shepherd has approved the RFC PR, and announces that the RFC enters a period for final comments before it will be approved (~1wk). At this stage, if major issues are raised, the RFC may return to Review.
4. Approved - The RFC PR is approved and merged to master, and the RFC is nonw ready to be implemented.
5. Planning - A PR is created with the Implementation Plan section of the RFC.
6. Implementing - Implemetation plan is approved and merged and the RFC is actively being implemented.
7. Done - Implementation is complete and merged across appropriate repositories.
8. Rejected - During the review period, the RFC may be rejected and then it will be marked as such.

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AWS CDK's RFC process owes its inspiration to the Yarn RFC process, Rust RFC process, React RFC process, and Ember RFC process