docs: Update GCS documentation for explicit credentials flow (PR #8142)

[royendo]

Summary

Updates the GCS connector documentation to reflect the new explicit credentials flow introduced in PR #8142.

Changes

• Two-step authentication flow: Documented the new Step 1 (Configure Authentication) → Step 2 (Configure Data Source) process
• Service Account JSON: Added UI instructions for uploading JSON key files directly in the interface
• HMAC Keys: Enhanced documentation with Google Cloud Console instructions and proper configuration examples
• Connector/Source separation: Updated all YAML examples to show proper separation between connector files and source files
• Deployment clarifications: Updated Rill Cloud deployment section to mention both authentication methods

Documentation Updates

New Sections

• "Using the Add Data UI" - Overview of the two-step process
• "Using the UI" subsections for both Service Account JSON and HMAC keys
• "Manual Configuration" subsections showing connector/source file structure

Updated Content

• All YAML examples now show proper connector/source separation
• Enhanced HMAC key generation instructions (Console + CLI)
• Clarified S3-compatible authentication mode for HMAC keys
• Updated deployment requirements

Related

• Closes PR GCS Explicit Credentials #8142 documentation checklist item
• Related Linear issue: APP-353/gcs-explicit-credential-flow-for-models

Test Plan

• Reviewed documentation for accuracy against code changes
• Verified all YAML examples are syntactically correct
• Checked links and references
• Ensured consistent formatting and style

🤖 Generated with Claude Code

[royendo]

from our call discussion, it does a decent job but will still require some hand holding as it uses some old syntax for source ingestion IE

type: source

connector: gcs

path: "gs://your-bucket/path/to/data.parquet"

But in terms of text and generic docs, its not a bad first pass.
Separates UI creation vs manual creation.

[royendo]

doclaude: fix source references to models

[royendo]

/DoClaude source is deprecated, use model instead

type: source

connector: gcs

path: "gs://your-bucket/path/to/data.parquet"

[royendo]

/claude apply changes: source is deprecated, use model instead

[github-actions]

✅ Claude processed feedback and attempted fixes.

• Branch: claude-ai-docs-creator-script
• Outcome: failure

If something looks off, you can push follow-ups or comment /claude apply again.

[royendo]

DoClaude review the inline comments and make changes

[royendo]

also, re add the supported files.

[github-actions]

✅ DoClaude processed all inline review comments

📝 Changes have been applied to the branch: claude-ai-docs-creator-script

🔄 Review comments have been marked as addressed

📚 The agent analyzed the review comments and may have updated .github/scripts/instructions.md with new learnings to improve future responses.

Review the commit and push additional changes if needed.

[royendo]

last few changes

[github-actions]

✅ DoClaude processed all inline review comments

📝 Changes have been applied to the branch: claude-ai-docs-creator-script

🔄 Review comments have been marked as addressed

📚 The agent analyzed the review comments and may have updated .github/scripts/instructions.md with new learnings to improve future responses.

Review the commit and push additional changes if needed.

[github-actions]

✅ DoClaude processed all inline review comments

📝 Changes have been applied to the branch: claude-ai-docs-creator-script

🔄 Review comments have been marked as addressed

📚 The agent analyzed the review comments and may have updated .github/scripts/instructions.md with new learnings to improve future responses.

Review the commit and push additional changes if needed.

[royendo]

last final 2?

[github-actions]

✅ DoClaude processed all inline review comments

📝 Changes have been applied to the branch: claude-ai-docs-creator-script

🔄 Review comments have been marked as addressed

📚 The agent analyzed the review comments and may have updated .github/scripts/instructions.md with new learnings to improve future responses.

Review the commit and push additional changes if needed.

[royendo]

@ericpgreen2 , @ericokuma

This gcs.md doc here is 100% modified by Claude taking into account in-line code review comments, making changes, then resolving the comments. It also appends to its own instructions.md to get "smarter over time"

<!-- Added from PR review - 2025-01-xx: Deployment documentation standards -->
### Deployment Instructions

**When documenting deployment and environment configuration:**

- ✅ **Keep it simple**: Use `rill env configure` without additional arguments
  - The CLI will walk through all required connectors interactively
  - WRONG: `rill env configure connector.gcs.google_application_credentials`
  - RIGHT: `rill env configure`

- ❌ **Don't use these commands in deploy docs**:
  - `rill env set` - Not part of standard deployment workflow
  - `rill env push` - Not part of standard deployment workflow
  - `rill env pull` - Not part of standard deployment workflow

The PR is an interesting one, (i need to work on the trigger to start the workload on PR comments (not in-line), its currently set to push).

The ideal workflow is: For PRs that require doc changes, we can trigger a doc creation, either locally with Claude or however to create an open/draft PR. The AI will read the code changes and modify (never create new files) the existing docs and open the PR. For any mistakes and fine tuning, we can in-line comment review, tag the engineer if the AI's understanding is correct then trigger the rewrite.

I assume itll take a few iterations but this way the doc review process can be completed with myself, and the user who worked on the code themselves.

Open to thoughts and ideas!
If you got any interesting PRs to create more examples, LMK.

[github-actions]

⚠️ DoClaude encountered an issue

Branch: claude-ai-docs-creator-script
Outcome: cancelled

Check the workflow logs for details.

[ericpgreen2]

The writing and structure generally looks good to me! Though perhaps @ericokuma also wants to review this as a Product stakeholder.

[ericpgreen2]

The AI will read the code changes and modify (never create new files) the existing docs and open the PR

I wonder if "never create new files" is too restrictive? Like, I see the model tests feature rightfully merited a new docs page.

[royendo]

The AI will read the code changes and modify (never create new files) the existing docs and open the PR

works for the agent because the local DOC AI can make new changes but a in-line code review should just make changes,

[ericokuma]

Feedback:

• this is quite important that it might benefit from an actual info box so it doesn't get glanced over

• since Service Account JSON is recommended, it might be good to put that in the title of the section i.e. Service Account JSON (recommended method)

• The "Deploy to Rill Cloud" section is a bit confusing especially this line: "When deploying your project to Rill Cloud, you must provide a JSON key file for a Google Cloud service account with appropriate read access/permissions to the buckets used in your project". Is this key file separate from the service account JSON?

[bito-code-review]

Based on the PR changes, here are responses to your feedback: 1) An info box would indeed help highlight the importance of authentication method selection - this could be added before the authentication methods section. 2) The section title could be updated to 'Method 1: Service Account JSON (Recommended)' to emphasize it's the preferred approach. 3) The 'Deploy to Rill Cloud' section refers to the same Service Account JSON file mentioned earlier - it's not a separate key file, but rather emphasizing that the JSON credentials configured in your connector must be present for cloud deployment to work.

docs/docs/build/connectors/data-source/gcs.md

## Method 1: Service Account JSON (Recommended)

Service Account JSON credentials provide the most secure and reliable authentication for GCS. This method works for both local development and Rill Cloud deployments.

[ericokuma]

Based on the PR changes, here are responses to your feedback: 1) An info box would indeed help highlight the importance of authentication method selection - this could be added before the authentication methods section. 2) The section title could be updated to 'Method 1: Service Account JSON (Recommended)' to emphasize it's the preferred approach. 3) The 'Deploy to Rill Cloud' section refers to the same Service Account JSON file mentioned earlier - it's not a separate key file, but rather emphasizing that the JSON credentials configured in your connector must be present for cloud deployment to work.

docs/docs/build/connectors/data-source/gcs.md

## Method 1: Service Account JSON (Recommended)

Service Account JSON credentials provide the most secure and reliable authentication for GCS. This method works for both local development and Rill Cloud deployments.

Whoa? what the heck is this bot??