DOC-1613: Document BYOC AWS centralized egress with Transit Gateway

[micheleRP]

Summary

• Adds two new pages under networking/byoc/aws/ documenting the beta NAT Gateway-Free Egress feature for BYOC AWS clusters: a concept + how-to page for configuring centralized egress at network creation, and a how-to for provisioning the customer-side hub VPC, Transit Gateway, and AWS RAM share.
• Updates nav and adds callouts on the existing BYOC create page (create-byoc-cluster-aws.adoc) and BYOVPC page (vpc-byo-aws.adoc) so customers can discover the new option.
• Cloud API path is currently hidden behind ifdef::show-preview-api[] while the network.egress_spec.aws.transit_gateway_id field is in PREVIEW. A preview-gated section is added on nat-free-egress.adoc, and a matching AWS BYOC network example is added to the controlplane-api.adoc partial (rendered on cloud-byoc-controlplane-api.adoc). Setting :show-preview-api: re-enables both in a future PR.

Context

• Jira: https://redpandadata.atlassian.net/browse/DOC-1613
• Epic: https://redpandadata.atlassian.net/browse/ENG-657
• fixVersion: 26.2 (Cloud ADP Foundations), planned 2026-07-14
• Feature flag: enable-transit-gateway-egress (LaunchDarkly, org-targeted)
• Currently AWS only. GCP and Azure paths are planned and will be tracked in separate DOC tickets.

Open items before publishing

These don't block review of the content, but PM/Eng sign-off is needed before the PR moves out of draft:

1. Beta entitlement model — SE-requested vs self-service for 26.2 GA.
2. Should the Cloud API egress_spec section be enabled at publish, or stay hidden until the field graduates from PREVIEW? Currently hidden.
3. Architecture diagram source — the page uses an ASCII diagram. The PRD has Image swap ROOT xrefs with include directive #3 ("AWS Transit Gateway — Redpanda BYOC ↔ Customer Connectivity"); confirm rights to reuse or commission a redrawn version.
4. UI screenshot of the Network wizard's Transit Gateway ID field (needs to be captured in a test org with the flag enabled).
5. Migration runbook — the PRD lists "migrate existing cluster without recreation" as acceptance criteria, but it's not yet supported. Migration content is deferred to a follow-up DOC ticket when the runbook is approved.

Preview pages

• Configure Centralized Egress with AWS Transit Gateway (new)
• Create an AWS Hub for Centralized Egress (new)
• Create a BYOC Cluster on AWS (updated)
• Create a BYOVPC Cluster on AWS (updated)
• What's New in Redpanda Cloud (updated)

Test plan

• Wait for Netlify preview to build.
• Verify both new pages render under BYOC → AWS in the left nav.
• Verify the Cloud API section does not render on nat-free-egress (it's gated behind ifdef::show-preview-api[]).
• Verify the new preview-gated AWS network example on cloud-byoc-controlplane-api.adoc does not render by default (also gated behind ifdef::show-preview-api[]).
• Verify cross-links between nat-free-egress and aws-hub-egress resolve in both directions.
• Verify the NOTE next to the Transit Gateway ID UI step on nat-free-egress renders, and its xref to aws-hub-egress resolves.
• Verify the troubleshooting table link in nat-free-egress jumps to the "Internet endpoints" section.
• Verify the callout on create-byoc-cluster-aws (TIP on the Network wizard step) renders correctly.
• Verify the updated outbound-internet bullet on vpc-byo-aws links to nat-free-egress.
• Verify the Beta badge displays on both new pages.
• Verify learning objective checkbox lists render on both new pages.

🤖 Generated with Claude Code

[netlify]

✅ Deploy Preview for rp-cloud ready!

Name	Link
🔨 Latest commit	8c6b2e4
🔍 Latest deploy log	https://app.netlify.com/projects/rp-cloud/deploys/6a0b9700844ace0007c9de9c
😎 Deploy Preview	https://deploy-preview-587--rp-cloud.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[coderabbitai]

Important

Review skipped

Auto incremental reviews are disabled on this repository.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 9e094e18-cc82-417c-99e2-32afef4c0b7e

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

📝 Walkthrough

Walkthrough

This pull request adds comprehensive documentation for a new beta feature: centralized egress for BYOC clusters on AWS. The change introduces two new how-to guides—one for provisioning a customer-managed Transit Gateway hub and one for configuring BYOC clusters to route traffic through it—alongside updates to the product's what's-new page, navigation tree, and existing cluster setup documentation. The feature enables customers to consolidate egress from multiple Redpanda clusters through a single hub VPC and NAT gateway instead of deploying per-cluster NAT resources.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• paulzhang97
• david-yu
• kbatuigas

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately reflects the primary objective of the PR: documenting the new BYOC AWS centralized egress feature using AWS Transit Gateway.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description check	✅ Passed	The PR description comprehensively covers objectives, context, preview links, test plan, and open items requiring sign-off.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch DOC-1613-byoc-aws-nat-free-egress

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[ppanagiotis]

Hello. I updated this document with everything related to Transit Gateway for AWS BYOC clusters:
https://docs.google.com/document/d/1_kU7Ux_LzuYjqNASb97cx8bJ_b23rggMCMScV9W_0-g

Feel free to use it.

[ppanagiotis]

@micheleRP I updated my document based on @david-yu’s comments. Please take a look if you think anything else should be added. Other than that, it looks good to me.

[Feediver1]

Reviewed against the Redpanda style guide and verified all xrefs. No broken links, no cross-repo single-source issues, CI is green. Findings are minor style polish.

Verified:

• All 5 xref targets in the new pages resolve in cloud-docs main (aws-hub-egress, nat-free-egress, create-byoc-cluster-aws, cloud-byoc-controlplane-api, transit-gateway). The new pages reference each other; that resolves once the PR merges.
• In-page anchors [#internet-endpoints] and [#automated-alternative] match their <<…>> references.
• No files in this PR are single-sourced from redpanda-data/docs. modules/manage/partials/controlplane-api.adoc is only included by three cloud-docs pages.
• All Bash code blocks have [,bash] language tags; bare ---- blocks are intentional ASCII diagrams.
• 3 measurable learning objectives per page, using observable Bloom verbs.
• ifdef::show-preview-api[] gating is correctly nested in controlplane-api.adoc (two consecutive endif::[] close the inner then outer ifdefs).

Style nits inline. The only one I'd push on is sentence-case for the page titles (Redpanda convention; sub-headings on both pages already follow it). The rest is optional polish.

Out of scope but called out for visibility: the test plan's TIP-in-numbered-list check is worth eyeballing on the Netlify preview because the list-continuation pattern is non-trivial — see comment on create-byoc-cluster-aws.adoc.

[Feediver1]

Maybe link to a description/defn of "preview" here?

[micheleRP]

I'll remove that clause about "preview"

[Feediver1]

I think a link to https://docs.redpanda.com/redpanda-cloud/networking/cidr-ranges/#what-are-cidrs would be helpful here

[Feediver1]

Need text here. Many of these sections say what the tasks are, but do not explain why users must complete them. It's sort of like blind faith. Ideally, users walk away from each step/task understanding why it is there in the first place.

[Feediver1]

Same as last comment here