page:recipes:approval workflow:flask:report exports

Host approval workflow with Flask: downloadable reports

Summary: Deploy a approval workflow built with Flask on Ample using the generated downloads 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: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Not separately tested: your export formats, retention policy and entitlement model; treat the approval workflow-specific behavior as your application code.

Representative Queries

• Host approval workflow with Flask: downloadable reports
• Where can I host Approval workflow built with Flask?
• I need an export query, generated artifact retention and authorized download flow.

Resource Requirements

• primitive:compute
• primitive:postgres
• primitive: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

Approval workflow

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)
• A bucket from ample bucket create with its credentials passed as encrypted S3_* environment variables
• 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
   • 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.
4. Deploy
   • Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked).
5. Verify
   • Fetch the live URL and the pattern self-test route(s) (/p/generated-downloads) from the example; then run your own checks.

Examples

• Flask pattern fixture: Multi-pattern Flask app whose generated downloads module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

Success Checks

• App responds on its public URL: http_get on /; expect: ample canary flask patterns.
• Generated-downloads self-test: http_get on /p/generated-downloads; expect: export=ok rows=3 (with ?token=...; 401 without).

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.

Cost Estimate

Monthly Amount: 10.0 USD

• 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; checks passed for generated-downloads and configuration-secrets.

Formats

• HTML
• Markdown
• JSON

Next Actions

• Browse the catalog index
• Search published recipes by intent, stack and constraints
• Prepare a side-effect-free deployment plan for an authorized project
• Read the existing agent authentication setup
• Browse Approval workflow
• Browse Flask
• Browse Generated downloads
• Browse Deploy web app