# Configure S3-compatible access for Spring Boot

## Summary

Object storage client for a Spring Boot app on Ample. Verified on Spring Boot: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok). 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`.

## Infrastructure requirements

- **Compute**: verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.)
- **S3-compatible object storage**: verified (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 (`./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 bucket from `ample bucket create` with credentials passed as encrypted S3_* environment variables
- An Ample account token with `servers:write`, `buckets:read`

## Exact tested configuration

- **template**: `jvm-21`
- **runtime**: `java`
- **size**: `s-1vcpu-2gb`
- **build**: `./mvnw -q -DskipTests package`
- **start**: `java -jar $(ls target/*.jar | grep -v -- '-plain' | head -n 1)`

## 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. **Create the bucket and pass its credentials.** Create it once with `ample bucket create`, then pass endpoint, region, bucket and keys with `--env`; use path-style addressing.

```
   ample deploy . --name <app-name> --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...
   ```
3. **Verify.** Fetch the live URL and `/p/browser-file-uploads` on the example; on failure read the build and runtime logs.

```
   ample logs <deployment_id> --kind build
   ```

## Tested examples

- **Spring Boot pattern fixture** (tests/deploy-canaries/spring-boot-patterns): Verified object storage client on Spring Boot.

## Success checks

- app responds on its public URL (`/` on the live URL, expect ample canary spring boot patterns)
- browser-file-uploads check from the example (`/p/browser-file-uploads` on the live URL, expect see the pattern fixture checks)

## Limitations

- Verified on the jvm-21 template at s-1vcpu-2gb; other sizes and Spring Boot major versions are not verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- PutObject and GetObject with path-style addressing are verified; other S3 operations are not.

## Cost estimate

Estimated 5.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371).
- app server x1 `s-1vcpu-1gb`: 5.00 USD

Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Verification evidence

- canary_run on 2026-09-21T02:34:39Z at revision `1d28ae0-dirty (CLI 0.1.21)`: Spring Boot pattern fixture deployed on Ample (`./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`); for this guide: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok). (expires 2027-03-20T02:34:39Z)

Last verified: 2026-09-21T02:34:39Z

## Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-21T03:19:59.461917+00:00 at revision `49962bcade4f`, binding state `current`, required scopes: `servers:write`, `buckets:read`.