page:recipes:csv import tool:spring boot:attachments

Host csv import tool with Spring Boot: file attachments

Deploy a csv import tool built with Spring Boot 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 Spring Boot: 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 Spring Boot: file attachments
• Where can I host CSV import tool built with Spring Boot?
• 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

• 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.

Prerequisites

• A Spring Boot project that builds and starts with the documented commands (./mvnw -q -DskipTests package or the Gradle wrapper) producing one application jar, then java -jar on the jvm-21 template (Temurin JDK 21) with server.port read from 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: ./mvnw -q -DskipTests package (or the Gradle wrapper) producing one application jar, then java -jar on the jvm-21 template (Temurin JDK 21) with server.port read from PORT. The server must bind 0.0.0.0 on PORT.
2. Implement the pattern on PostgreSQL: 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).
3. Wire object storage: Create the bucket(s), then pass endpoint, region, bucket and keys as --env values.
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/browser-file-uploads) from the example; then run your own checks.

Limitations

• Verified on the jvm-21 template at s-1vcpu-2gb with the example fixture; other sizes and templates 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.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• 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.

Examples

• Spring Boot pattern fixture: Multi-pattern Spring Boot app whose browser file uploads module was checked live.