page:recipes:asset library:asp net core:data exports

Host asset library with ASP.NET Core: Data Exports

Summary

Deploy an asset library built with ASP.NET Core 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 ASP.NET Core: 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 asset library-specific behavior as your application code.

Prerequisites

• A ASP.NET Core project that builds and starts with the documented commands (dotnet publish -c Release -o out in the builder, then dotnet .dll on the dotnet-10 template with ASPNETCORE_URLS bound to PORT)
• 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

Workflow Steps

1. Build and start

   • Command: dotnet publish -c Release -o out in the builder, then dotnet .dll on the dotnet-10 template with ASPNETCORE_URLS bound to PORT. The server must bind 0.0.0.0 on PORT.

2. Implement the pattern on PostgreSQL

   • The fixture's module implements generated downloads: 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). 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 Keep private data in an unpublished bucket.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

   • Command: ample deploy . --name --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=....

5. Verify

   • Command: ample logs --kind build then --kind runtime.

Cost Estimate

• Currency: USD
• Monthly Amount: $10.00
• Components:
  • App server (s-1vcpu-1gb): $5.00
  • Managed PostgreSQL database (s-1vcpu-1gb): $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.

Success Checks

• HTTP GET on the app's public URL expects: ample canary asp net core patterns.
• HTTP GET on /p/generated-downloads expects: export=ok rows=3 (with ?token=...; 401 without).

Limitations

• Verified on the dotnet-10 template at s-1vcpu-1gb with the example fixture; other sizes, templates and ASP.NET Core major versions are not verified.
• The asset library itself (your export formats, retention policy, and entitlement model) is application code and was not separately tested.
• 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.

Examples

• ASP.NET Core pattern fixture
  • Source: tests/deploy-canaries/asp-net-core-patterns
  • Description: Multi-pattern ASP.NET Core app whose generated downloads module was checked live; the module is under tests/deploy-canaries/_pattern-modules.