# Host community forum with Flask: tenant-scoped workspaces

Deploy a community forum built with Flask on Ample using the multi-tenant relational data 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 Flask: a tenant column on every row and query, with a cross-tenant read returning nothing (tenant_isolation=ok). Not separately tested: your tenant model, membership and per-tenant authorization; treat the community forum-specific behavior as your application code.

## Overview

**Family:** Workload recipe  
**Summary:** Deploy a community forum built with Flask on Ample using the multi-tenant relational data pattern.

## Representative Queries
- Host community forum with Flask: tenant-scoped workspaces  
- Where can I host Community forum built with Flask?  
- I need an explicit tenant model and application-enforced tenant isolation tests.

## Resource Requirements
- primitive:compute  
- primitive:postgres

## 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.

## Framework
**Framework:** Flask  
**Workload:** Community forum  
**Release Status:** published  
**Support Status:** verified  
**Execution Status:** ready

## 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)  
- An Ample account token with servers:write, databases:read

## Tested Configuration
- **Template:** python-3.12  
- **Runtime:** python  
- **Size:** s-1vcpu-1gb  
- **Install Command:** python3 -m pip install --target .ample/python -r requirements.txt  
- **Start Command:** 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 multi-tenant relational data: a tenant column on every row and query, with a cross-tenant read returning nothing (tenant_isolation=ok). 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. Command: ample deploy . --name  --public --start "python3 app.py"
4. **Verify**: Fetch the live URL and the pattern self-test route(s) (/p/multi-tenant-relational-data) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`. Command: ample logs  --kind build

## Examples
- **Flask pattern fixture**: Multi-pattern Flask app whose multi-tenant relational data module was checked live; the module is under tests/deploy-canaries/_pattern-modules.  
  
## Success Checks
1. **App responds on its public URL**  
   - **Kind:** http_get  
   - **Path:** /  
   - **Expect:** ample canary flask patterns  
2. **Multi-tenant-relational-data self-test**  
   - **Kind:** http_get  
   - **Path:** /p/multi-tenant-relational-data  
   - **Expect:** tenant_isolation=ok

## 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 community forum itself (your tenant model, membership and per-tenant authorization) 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.  
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.

## Cost Estimate
- **Currency:** USD
- **Monthly Amount:** 10.0
- **Basis:** size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- **Components:**
   - App server: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0
   - Managed PostgreSQL database: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0
- **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.

## Evidence Summary
- **Canary Run:** Flask pattern fixture deployed on Ample (pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template); checks passed for multi-tenant-relational-data and configuration-secrets. Pattern proof: a tenant column on every row and query, with a cross-tenant read returning nothing (tenant_isolation=ok).
- **Observations:**
   - **Kind:** canary_run  
   - **Observed At:** 2026-09-21T01:14:18Z
   - **Implementation Revision:** 50dbac567d2c5cc8e55e6c748a646be0025d9cfb-dirty (CLI 0.1.21)
   - **Expires At:** 2027-03-20T01:14:18Z

## 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:** [Link](/content/recipes/community-forum/flask/tenant-workspaces/index.html)  
- **Markdown:** [Link](/content/recipes/community-forum/flask/tenant-workspaces.md)  
- **JSON:** [Link](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Acommunity-forum%3Aflask%3Atenant-workspaces)