Enforce private-file authorization for Starlette

Summary

Private file access for a Starlette app on Ample. Verified on Starlette: a role-to-document access model with negative tests (401, 403) and an authorized private-bucket round-trip (private=ok). Build and start: pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template.

Prerequisites

• A Starlette project (pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template)
• A PostgreSQL driver reading DATABASE_URL at runtime
• A bucket from ample bucket create with credentials passed as encrypted S3_* environment variables
• An Ample account token with servers:write, databases:read, buckets:read

Resource Requirements

• primitive:compute
• primitive:postgres
• primitive:s3-compatible-object-storage

Workflow Steps

1. Build and start
   pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template; the server must bind 0.0.0.0 on PORT.
2. Create the bucket and pass its credentials
   Create it once with ample bucket create, then pass endpoint, region, bucket and keys with --env; use path-style addressing.

   ample deploy . --name  --public --start "python3 run.py" --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...`
   

3. Authorize before touching storage
   Return 401 for unauthenticated requests and 403 for the wrong role; keep the bucket unpublished and stream objects through the app.
4. Verify
   Fetch the live URL and /p/private-document-library on the example; on failure read the build and runtime logs.

   ample logs  --kind build
   

Success Checks

• App responds on its public URL
  • kind: http_get
  • path: /
  • expect: ample canary starlette patterns
• Private-document-library check from the example
  • kind: http_get
  • path: /p/private-document-library
  • expect: see the pattern fixture checks

Limitations

• Verified on the python-3.12 template at s-1vcpu-1gb; other sizes and Starlette major versions are not verified.
• Region, compliance attestations and request-duration limits are unknown and not claimed.
• Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified.
• PutObject and GetObject with path-style addressing are verified; other S3 operations are not.

Cost Estimate

• Currency: USD
• Monthly Amount: $10.00
• Components:
  • App server: s-1vcpu-1gb - $5.00
  • Managed PostgreSQL database: s-1vcpu-1gb - $5.00
  • Note: Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.

Evidence Summary

• Kind: canary_run
• Summary: Starlette pattern fixture deployed on Ample (pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template); for this guide: a role-to-document access model with negative tests (401, 403) and an authorized private-bucket round-trip (private=ok).
• Observed At: 2026-09-21T01:21:36Z
• Implementation Revision: 50dbac567d2c5cc8e55e6c748a646be0025d9cfb-dirty (CLI 0.1.21)
• Expires At: 2027-03-20T01:21:36Z

Examples

Starlette pattern fixture

• Description: Verified private file access on Starlette.
• Source Reference: tests/deploy-canaries/starlette-patterns

Next Actions

• Browse the catalog index
• Search published recipes by intent, stack and constraints
• Prepare a side-effect-free deployment plan for an authorized project
• Read the existing agent authentication setup
• Browse Starlette
• Browse Connect app to storage
• Browse Private document library