### 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.