ECE: Clarify HTTPS requirement for Cloud UI browser access (port 12443)

[magdalena-alicja-michalska]

Summary

Starting with ECE 3.7.0, browser access to the Cloud UI requires HTTPS on port 12443. HTTP on port 12400 remains functional for programmatic API access (e.g., curl) but browsers cannot render the UI over HTTP due to a Content-Security-Policy: upgrade-insecure-requests directive.

This was an undocumented change that has caused customer confusion (e.g., elastic/sdh-control-plane#13040).

Changes

log-into-cloud-ui.md:

• Removed the http://<FIRST_HOST>:12400 URL
• Added a note explaining that HTTPS on port 12443 is required for browser access since ECE 3.7.0

ece-networking-prereq.md:

• Updated the Cloud UI port row to clarify 12443 is required and 12400 is optional (API only)
• Added a note explaining the HTTPS requirement for browser access

Context

• The CSP directive was introduced in ECE 3.7.0 as a side effect of a library migration (elastic/cloud#117047)
• The behavior was acknowledged and kept by the team (elastic/cp-hosted-team#2423) but never documented
• Related engineering issue: elastic/cloud#131038
• Companion PR for install output: elastic/cloud#156490

Test plan

• Verify docs build without errors
• Review wording with @platform-docs team
• Confirm admonition renders correctly

Made with Cursor

[github-actions]

Elastic Docs AI PR menu

Check the box to run an AI review for this pull request.

• Review docs changes (docs-review). Status: not started.

Powered by GitHub Agentic Workflows and docs-actions. For more information, reach out to the docs team.

[github-actions]

🔍 Preview links for changed docs

• deploy-manage/deploy/cloud-enterprise/ece-networking-prereq.md
• deploy-manage/deploy/cloud-enterprise/log-into-cloud-ui.md

[github-actions]

✅ Elastic Docs Style Checker (Vale)

No issues found on modified lines!

---

The Vale linter checks documentation changes against the Elastic Docs style guide. To use Vale locally or report issues, refer to Elastic style guide for Vale.