# Host product catalog with Django: relational catalog data

Deploy a product catalog built with Django on Ample using the transactional workflows 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. Verified on Django: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Not separately tested: your domain records, validation rules and concurrency policy; treat the product catalog-specific behavior as your application code.

## Summary
- **Workload:** Product catalog
- **Framework:** Django
- **Release Status:** Published
- **Support Status:** Verified
- **Execution Status:** Ready

## Representative Queries
- Host product catalog with Django: relational catalog data
- Where can I host Product catalog built with Django?
- I need catalog tables, transactional update logic and application-level access boundaries.

## Resource Requirements
- **Compute**
- **Postgres**

## Infrastructure Requirements
1. **Compute**
   - **Status:** Verified
   - **Summary:** Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
2. **Postgres**
   - **Status:** Verified
   - **Summary:** Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

## Prerequisites
- A Django project that builds and starts with the documented commands (pip install into .ample/python from requirements.txt, then waitress serving project.wsgi from run.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)
- An Ample account token with servers:write, databases:read

## Limitations
- Verified on the python-3.12 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Django major versions are not verified.
- The product catalog itself (your domain records, validation rules and concurrency 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.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.

## Workflow Steps
1. **Build and start** 
   - pip install into .ample/python from requirements.txt, then waitress serving project.wsgi from run.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 transactional workflows: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
3. **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.
4. **Verify** 
   - Fetch the live URL and the pattern self-test route(s) (/p/transactional-workflows) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.

## Success Checks
- App responds on its public URL: **ample canary django patterns**
- Transactional-workflows self-test: **tx=ok history=2 conflict=rejected**

## Cost Estimate
- **Currency:** USD
- **Monthly Amount:** $10.00

### Components
| Name                          | Size            | Quantity | Monthly Amount |
|-------------------------------|-----------------|----------|----------------|
| App server                   | s-1vcpu-1gb    | 1.0      | $5.00          |
| Managed PostgreSQL database   | s-1vcpu-1gb    | 1.0      | $5.00          |

**Note:** Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Examples
### Django pattern fixture
- **Description:** Multi-pattern Django app whose transactional workflows module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
- **Source Ref:** tests/deploy-canaries/django-patterns

## Evidence Summary
1. **Summary:** Django pattern fixture deployed on Ample. 
   - **Observed At:** 2026-09-20T03:31:44Z

2. **Summary:** The same Django app deployed with a --release-command migration;
   - **Observed At:** 2026-09-20T01:54:51Z

**Last Verified At:** 2026-09-20T03:31:44Z

## Formats
- **HTML:** [Link](/content/recipes/product-catalog/django/relational-catalog/index.html)
- **Markdown:** [Link](/content/recipes/product-catalog/django/relational-catalog.md)
- **JSON:** [Link](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aproduct-catalog%3Adjango%3Arelational-catalog)