# Host Asset Library with Flask: Structured Data Imports

Deploy an asset library built with Flask on Ample using the bulk import staging 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 Flask: a CSV staged as an object, row-level validation with per-row errors recorded, and a restart-safe import keyed by import id (imported=2 rejected=1 restart=ok). Not separately tested: your import format, mapping and conflict rules; treat the asset library-specific behavior as your application code.

## Representative Queries
- Host asset library with Flask: structured data imports
- Where can I host Asset library built with Flask?
- I need a workload-specific import mapping, conflict rules and restart behavior.

## Resource Requirements
- **Compute**
- **Postgres**
- **S3-compatible object storage**

## Infrastructure Requirements
- **Compute**: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
- **Postgres**: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.
- **S3-compatible object storage**: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

## Framework
Flask

## Workload
Asset library

## Release Status
Published

## Support Status
Verified

## Execution Status
Ready

## Prerequisites
1. 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).
2. A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env).
3. A bucket from `ample bucket create` with its credentials passed as encrypted S3_* environment variables.
4. An Ample account token with servers:write, databases:read, buckets:read.

## 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

## 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 bulk import staging: a CSV staged as an object, row-level validation with per-row errors recorded, and a restart-safe import keyed by import id (imported=2 rejected=1 restart=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.
5. **Verify**: Fetch the live URL and the pattern self-test route(s) (/p/bulk-import-staging) from the example; then run your own checks. On failure read `ample logs --kind build` then `--kind runtime`.

## Examples
- **Flask pattern fixture**: Multi-pattern Flask app whose bulk import staging module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

## Success Checks
- **App responds on its public URL**: [GET] / expecting "ample canary flask patterns"
- **Bulk-import-staging self-test**: [GET] /p/bulk-import-staging expecting "imported=2 rejected=1 restart=ok"

## Limitations
- Verified on the python-3.12 template at s-1vcpu-1gb; other sizes, templates and Flask major versions are not verified.
- The asset library itself (your import format, mapping and conflict rules) is application code and was not separately tested.

## Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 10.0
- **Basis**: Size prices from pricing.toml.

**Components**:
1. App server (size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0)
2. Managed PostgreSQL database (size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0)

*Note*: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

## Evidence Summary
- **Canary Run**: Flask pattern fixture deployed on Ample. Checks passed for bulk-import-staging and configuration-secrets.

## Last Verified At
2026-09-21T01:14:18Z

## Unknowns
- Region availability is unknown until a verified region fact is recorded.
- Compliance attestations are unknown; none are claimed.

## Formats
- **HTML**: [Host asset library](/content/recipes/asset-library/flask/data-imports/index.html)
- **Markdown**: [Host asset library](/content/recipes/asset-library/flask/data-imports.md)

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