page:recipes:csv import tool:asp net core:attachments

Host csv import tool with ASP.NET Core: file attachments

Summary

Deploy a csv import tool built with ASP.NET Core on Ample using the browser file uploads 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: content-type and size validation that rejects disallowed files, an object written to a private bucket and a row linking the record to the object key (reject=ok upload=ok linked=ok). Not separately tested: your upload UI, allowed types, size limits and virus scanning; treat the csv import tool-specific behavior as your application code.

Representative Queries

• Host csv import tool with ASP.NET Core: file attachments
• Where can I host CSV import tool built with ASP.NET Core?
• I need a restricted upload flow, file validation and record-to-object linkage.

Resource Requirements

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

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.
3. 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.

Workflow Steps

1. Build and start
   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 browser file uploads: content-type and size validation that rejects disallowed files, an object written to a private bucket and a row linking the record to the object key (reject=ok upload=ok linked=ok). 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
   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 --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...

5. Verify
   Fetch the live URL and the pattern self-test route(s) (/p/browser-file-uploads) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime.
   ample logs --kind build

Limitation

• 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 csv import tool itself (your upload UI, allowed types, size limits and virus scanning) is application code and was not separately tested; the pattern checks are what was verified.

Cost Estimate

• Monthly Amount: $10.00 USD
  • Components:
  1. App Server (size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: $5.00)
  2. Managed PostgreSQL Database (size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: $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.

Evidence Summary

• Canary Run: ASP.NET Core pattern fixture deployed on Ample; checks passed for browser-file-uploads and configuration-secrets.
  • Observed At: 2026-09-21T01:15:54Z
  • Summary: Content-type and size validation that rejects disallowed files, an object written to a private bucket and a row linking the record to the object key (reject=ok upload=ok linked=ok).

Next Actions

1. Browse the catalog index
2. Search published recipes by intent, stack and constraints
3. Prepare a side-effect-free deployment plan for an authorized project
4. Read the existing agent authentication setup
5. Browse CSV import tool
6. Browse ASP.NET Core
7. Browse Browser file uploads
8. Browse Deploy web app