### Host approval workflow with Rails: private attachments

Deploy a approval workflow built with Rails on Ample using the private document library pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL, a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables. Verified on Rails: a role-to-document access model with negative tests (401 without identity, 403 for the wrong role) and a private-bucket round-trip for the allowed role (private=ok). Not separately tested: your identity integration and role assignments; treat the approval workflow-specific behavior as your application code.

#### Representative Queries
- Host approval workflow with Rails: private attachments
- Where can I host Approval workflow built with Rails?
- I need attachment metadata, access checks and a tested private object access path.

#### Prerequisites
- A Rails project that builds and starts with the documented commands (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rails server` reading PORT on the ruby-3.4 template with RAILS_ENV=production)
- A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
- A bucket from `ample bucket create` with its credentials passed as encrypted S3_* environment variables
- An Ample account token with servers:write, databases:read, buckets:read

#### Workflow Steps
1. **Build and start**  
   Bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rails server` reading PORT on the ruby-3.4 template with RAILS_ENV=production. The server must bind 0.0.0.0 on PORT.

2. **Implement the pattern on PostgreSQL**  
   The fixture's module implements private document library: a role-to-document access model with negative tests (401 without identity, 403 for the wrong role) and a private-bucket round-trip for the allowed role (private=ok). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. **Wire object storage**  
   Create the bucket(s), then pass endpoint, region, bucket and keys as --env values. Use path-style addressing. Keep private data in an unpublished bucket.

4. **Deploy**  
   Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.  
   Command: `ample deploy . --name  --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...`

5. **Verify**  
   Fetch the live URL and the pattern self-test route(s) (/p/private-document-library) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.  
   Command: `ample logs  --kind build`

#### Success Checks
- App responds on its public URL (expect: ample canary rails patterns)
- Private-document-library self-test (expect: private=ok with ?role=owner; 401 without, 403 for viewer)

#### Limitations
- Verified on the ruby-3.4 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Rails major versions are not verified.
- The approval workflow itself (your identity integration and role assignments) is application code and was not separately tested; the pattern checks are what was verified.

#### Costs Estimate
- Monthly Amount: **$10.00**
- App Server: **$5.00**
- Managed PostgreSQL Database: **$5.00**
- Note: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

#### Evidence Summary
- **Rails pattern fixture** deployed on Ample (checks passed for private-document-library and configuration-secrets).
- The same Rails app deployed with a --release-command migration.

#### Last Verified At
- 2026-09-20T21:55:28Z

#### Links
- [HTML Format](/content/recipes/approval-workflow/rails/private-attachments/index.html)
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