# Configure S3-compatible access for Flask

## Summary

Object storage client for a Flask app on Ample. Verified on Flask: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok). Build and start: pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template.

## Infrastructure requirements

- Verified compute: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request.
- Verified S3-compatible object storage: Buckets are S3-compatible with issued credentials.

## Prerequisites

- A Flask project (pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template)
- A bucket from `ample bucket create` with credentials passed as encrypted S3_* environment variables
- An Ample account token with servers:write, buckets:read

## Exact tested configuration

- template: `python-3.12`
- runtime: `python`
- size: `s-1vcpu-1gb`
- install: `python3 -m pip install --target .ample/python -r requirements.txt`
- start: `PYTHONPATH=.ample/python:${PYTHONPATH:-} python3 app.py`

## 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. **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 <app-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=...
   ```
3. **Verify.** Fetch the live URL and /p/browser-file-uploads on the example; on failure read the build and runtime logs.
   
   ```
   ample logs <deployment_id> --kind build
   ```

## Tested examples

- **Flask pattern fixture**: Verified object storage client on Flask.

## Success checks

- app responds on its public URL (`/` on the live URL)
- browser-file-uploads check from the example (`/p/browser-file-uploads` on the live URL)

## Limitations

- Verified on the python-3.12 template at s-1vcpu-1gb; other sizes and Flask major versions are not verified.
- PutObject and GetObject with path-style addressing are verified; other S3 operations are not.

## Cost estimate

Estimated 5.00 USD per month (size prices from pricing.toml).
- app server x1 `s-1vcpu-1gb`: 5.00 USD

## Verification evidence

- canary_run on 2026-09-21T01:14:18Z at revision `50dbac567d2c5cc8e55e6c748a646be0025d9cfb-dirty (CLI 0.1.21)`: Flask pattern fixture deployed on Ample. (expires 2027-03-20T01:14:18Z)

## Execution binding

MCP tool `ample_deploy`, binding state `current`, required scopes: servers:write, buckets:read.