# Host documentation site with Flask: object-stored public media

Deploy a documentation site built with Flask on Ample using the public media 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, and a published bucket serves public assets from the CDN host. Verified on Flask: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly. Not separately tested: your media processing, object layout and cache policy; treat the documentation site-specific behavior as your application code.

## Representative Queries
- Host documentation site with Flask: object-stored public media
- Where can I host Documentation site built with Flask?
- I need an object layout, public asset URL policy and CDN delivery configuration.

## Prerequisites
- A Flask project that builds and starts with the documented commands (pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template)
- 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 and a second, published bucket for public assets (CDN_*)
- An Ample account token with servers:write, databases:read, buckets:read

## Workflow Steps
1. **Build and start**  
   pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template. The server must bind 0.0.0.0 on PORT.

2. **Implement the pattern on PostgreSQL**  
   The fixture's module implements public media library: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly. 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 Keep private data in an unpublished bucket. Publish only the bucket that serves public assets and reference its CDN URL.

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

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

## Limitations
- Verified on the python-3.12 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Flask major versions are not verified.
- The documentation site itself (your media processing, object layout and cache policy) is application code and was not separately tested; the pattern checks are what was verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.

## Examples
- **Flask pattern fixture**  
  Multi-pattern Flask app whose public media library module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
  - Source: `tests/deploy-canaries/flask-patterns`

## Cost Estimate
| Item                             | Monthly Amount |  
|----------------------------------|----------------|
| app server (size: s-1vcpu-1gb)  | $5.00          |  
| managed PostgreSQL database      | $5.00          |  
| **Total**                        | **$10.00**     |

## Success Checks
1. app responds on its public URL
   - Kind: http_get
   - Path: /
   - Expect: ample canary flask patterns

2. public-media-library self-test
   - Kind: http_get
   - Path: /p/public-media-library
   - Expect: a CDN URL whose content is served publicly

## Evidence Summary
- **Canary Run**: Flask pattern fixture deployed on Ample; checks passed for public-media-library and configuration-secrets. Pattern proof: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly.
- Observed At: 2026-09-21

## Formats
- [HTML Version](/content/recipes/documentation-site/flask/public-media/index.html)
- [Markdown Version](/content/recipes/documentation-site/flask/public-media.md)
- [JSON Version](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Adocumentation-site%3Aflask%3Apublic-media)