# Host mobile backend with Spring Boot: Postgres-backed state

## Summary
Deploy a mobile backend built with Spring Boot on Ample using the durable job state 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 jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true). Not separately tested: your job types, payload schema and retry policy; treat the mobile backend-specific behavior as your application code.

## Representational Queries
- Host mobile backend with Spring Boot: Postgres-backed state
- Where can I host Mobile backend built with Spring Boot?
- I need a durable state schema and retry/recovery semantics implemented by application code.

## Resource Requirements
- primitive:compute
- primitive:postgres

## Infrastructure Requirements
### Compute
- **Label:** 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
- **Label:** 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.

## 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)  
- An Ample account token with servers:write, databases: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:**  
   The fixture's module implements durable job state: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. **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`

4. **Verify:**  
   Fetch the live URL and the pattern self-test route(s) (/p/durable-job-state) 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  
   - Kind: http_get  
   - Path: /  
   - Expect: ample canary spring boot patterns  
- Durable-job-state self-test  
   - Kind: http_get  
   - Path: /p/durable-job-state  
   - Expect: job=done attempts=1 idempotent=true

## Examples
- **Title:** Spring Boot pattern fixture  
   **Description:** Multi-pattern Spring Boot app whose durable job state module was checked live; the module is under tests/deploy-canaries/_pattern-modules.  
   **Source Ref:** tests/deploy-canaries/spring-boot-patterns

## 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 mobile backend itself (your job types, payload schema and retry policy) 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.

## 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, monthlyAmount: 5.0  
   - Managed PostgreSQL database, size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 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.

## Evidence Summary
- **Kind:** canary_run  
   **Summary:** Spring Boot pattern fixture deployed on Ample; checks passed for durable-job-state and configuration-secrets. Pattern proof: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true).  
   **Observed At:** 2026-09-21T02:34:39Z  
   **Implementation Revision:** 1d28ae0-dirty (CLI 0.1.21)  
   **Expires At:** 2027-03-20T02:34:39Z

## Next Actions
- **Action ID:** browse-catalog  
   **Label:** Browse the catalog index  
   **Method:** GET  
   **Relative Path:** /v1/catalog

- **Action ID:** search-recipes  
   **Label:** Search published recipes by intent, stack and constraints  
   **Method:** POST  
   **Relative Path:** /v1/catalog/search  
   **Parameters:** {"body":{"limit":5,"query":"Host mobile backend with Spring Boot: Postgres-backed state"}}

- **Action ID:** plan:page:recipes:mobile-backend:spring-boot:persistent-state  
   **Label:** Prepare a side-effect-free deployment plan for an authorized project  
   **Method:** POST  
   **Relative Path:** /v1/catalog/plan  
   **Parameters:** {"body":{"inputs":{},"projectId":"","recipeId":"page:recipes:mobile-backend:spring-boot:persistent-state","recipeRevision":"r1"}}

- **Action ID:** auth-setup  
   **Label:** Read the existing agent authentication setup  
   **Method:** GET  
   **Relative Path:** /mcp/setup

- **Action ID:** browse:workload:mobile-backend  
   **Label:** Browse Mobile backend  
   **Method:** GET  
   **Relative Path:** /v1/catalog/nodes/workload%3Amobile-backend

- **Action ID:** browse:stack:framework-spring-boot  
   **Label:** Browse Spring Boot  
   **Method:** GET  
   **Relative Path:** /v1/catalog/nodes/stack%3Aframework-spring-boot

- **Action ID:** browse:pattern:durable-job-state  
   **Label:** Browse Durable job state  
   **Method:** GET  
   **Relative Path:** /v1/catalog/nodes/pattern%3Adurable-job-state

- **Action ID:** browse:intent:deploy-api  
   **Label:** Browse Deploy API  
   **Method:** GET  
   **Relative Path:** /v1/catalog/nodes/intent%3Adeploy-api