## Host inventory manager with Spring Boot: relational workspace data

### Summary
Deploy a inventory manager built with Spring Boot on Ample using the relational records 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. Verified on Spring Boot: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). Not separately tested: your record schema, states and access rules; treat the inventory manager-specific behavior as your application code.

### Resource Requirements
- **Compute**
- **Postgres**

### 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.

### Framework
Spring Boot

### Workload
Inventory manager

### Release Status
Published

### Support Status
Verified

### Execution Status
Ready

### Prerequisites
1. 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.
2. A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with `--env`).
3. An Ample account token with `servers:write`, `databases:read`.

### Workflow Steps
- **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.
- **Implement the pattern on PostgreSQL**: The fixture's module implements relational records: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). Copy the approach into your schema; keep migrations idempotent and run them with `--release-command`.
- **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. Command: `ample deploy . --name --public`.
- **Verify**: Fetch the live URL and the pattern self-test route(s) (`/p/relational-records`) from the example; then run your own checks. On failure read `ample logs --kind build` then `--kind runtime`. Command: `ample logs --kind build`.

### Success Checks
- App responds on its public URL
- Relational-records self-test

### 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 inventory manager itself (your record schema, states and access rules) is application code and was not separately tested; the pattern checks are what was verified.

### 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

### Next Actions
- Browse the catalog index
- Search published recipes by intent, stack and constraints
- Prepare a side-effect-free deployment plan for an authorized project
- Read the existing agent authentication setup
- Browse Inventory manager
- Browse Spring Boot
- Browse Relational records
- Browse Deploy web app

### Examples
- **Spring Boot pattern fixture**: Multi-pattern Spring Boot app whose relational records module was checked live; the module is under tests/deploy-canaries/_pattern-modules.