Host public directory with Flask: object-stored public media

Deploy a public directory built with Flask on Ample using the public media library 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, and a published bucket serves public assets from the CDN host. Verified on Flask: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly. Not separately tested: your media processing, object layout and cache policy; treat the public directory-specific behavior as your application code.

Representative Queries

• Host public directory with Flask: object-stored public media
• Where can I host Public directory built with Flask?
• I need an object layout, public asset URL policy and CDN delivery configuration.

Resource Requirements

• primitive:compute
• primitive:postgres
• primitive:s3-compatible-object-storage
• primitive:cdn

Infrastructure Requirements

Compute

• Label: 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.

Postgres

• Label: 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.

S3-Compatible Object Storage

• Label: S3-compatible object storage
• Status: Verified
• Summary: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

CDN

• Label: CDN
• Status: Verified
• Summary: The CDN host serves objects from published buckets. It does not front app compute and is not a cache or key-value store.

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 and a second, published bucket for public assets (CDN_*)
• An Ample account token with servers:write, databases:read, buckets:read

Workflow Steps

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.

Implement the pattern on PostgreSQL

• The fixture's module implements public media library: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly. Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

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. Publish only the bucket that serves public assets and reference its CDN URL.

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.

  ample deploy . --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=... --env CDN_PUBLIC_URL=...
  

Verify

• Fetch the live URL and the pattern self-test route(s) (/p/public-media-library) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime.

  ample logs  --kind build
  

Examples

Flask pattern fixture

• Description: Multi-pattern Flask app whose public media library module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

Success Checks

• App responds on its public URL
• Public-media-library self-test

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 public directory itself (your media processing, object layout, and cache policy) is application code and was not separately tested; the pattern checks are what was verified.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Basis: Size prices from pricing.toml (loaded by the API) at build revision ...

Components

• App server - Size: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0
• Managed PostgreSQL database - Size: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0

Evidence Summary

• Canary run: Flask pattern fixture deployed on Ample; checks passed for public-media-library and configuration-secrets. Pattern proof: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly.

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