# Host subscription content with Spring Boot: authorized file delivery

## Summary
Deploy a subscription content built with Spring Boot 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 Spring Boot: 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 subscription content-specific behavior as your application code.

## Representative Queries
- Host subscription content with Spring Boot: authorized file delivery
- Where can I host Subscription content built with Spring Boot?
- I need a file entitlement model and an application-enforced download authorization flow.

## Resource Requirements
- `primitive:compute`
- `primitive:postgres`
- `primitive:s3-compatible-object-storage`

## Infrastructure Requirements
### Compute
- **Primitive ID:** `primitive: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.

### Postgres
- **Primitive ID:** `primitive: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.

### S3-compatible object storage
- **Primitive ID:** `primitive: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.

## 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

## 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)

## 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**  
   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**  
   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/generated-downloads) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.  
   `ample logs  --kind build`

## Cost Estimate
- **Currency:** USD
- **Monthly Amount:** 10.0
- **Basis:** size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- **Components:**
  - **App server**  
    - **Size:** s-1vcpu-1gb  
    - **Quantity:** 1.0  
    - **Monthly Amount:** 5.0
  - **Managed PostgreSQL database**  
    - **Size:** 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.

## Success Checks
- **App responds on its public URL**  
  - **Kind:** http_get  
  - **Path:** `/`  
  - **Expect:** ample canary spring boot patterns
- **Generated-downloads self-test**  
  - **Kind:** http_get  
  - **Path:** `/p/generated-downloads`  
  - **Expect:** export=ok rows=3 (with ?token=...; 401 without)

## Limitations
- Verified on the jvm-21 template at s-1vcpu-2gb with the example fixture; other sizes, templates and Spring Boot major versions are not verified.
- The subscription content itself (your export formats, retention policy and entitlement model) is application code and was not separately tested; the pattern checks are what was verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.
- PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs and lifecycle rules are not.

## Evidence Summary
- **Kind:** canary_run  
  - **Summary:** Spring Boot pattern fixture deployed on Ample; checks passed for generated-downloads and configuration-secrets.
- **Kind:** canary_run  
  - **Summary:** The same Spring Boot app deployed with a --release-command migration; the marker it created was readable after activation.

## Next Actions
1. **Browse the catalog index**  
   - **Action ID:** `browse-catalog`  
   - **Method:** GET  
   - **Relative Path:** `/v1/catalog`
2. **Search published recipes by intent, stack and constraints**  
   - **Action ID:** `search-recipes`  
   - **Method:** POST  
   - **Relative Path:** `/v1/catalog/search`
3. **Prepare a side-effect-free deployment plan for an authorized project**  
   - **Action ID:** `plan:page:recipes:subscription-content:spring-boot:download-delivery`  
   - **Method:** POST  
   - **Relative Path:** `/v1/catalog/plan`