INFRASTRUCTURE

What it needs

• 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.)

PREREQUISITES

Before you start

• 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)
• An Ample account token with servers:write

TESTED CONFIGURATION

Exactly what was tested

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

STEP BY STEP

How to do it

1. 1

Read the failure code

Deploy is synchronous. Exit 1 with build_failed means the isolated build failed; health_check_failed means the app built but never answered on PORT (it crashed at boot or bound the wrong port); public_ingress_failed means it answered on PORT but the public URL returned an error status (a request handler or bootstrap failed); exit 2 means a required preflight action is blocking.

2. 2

Read the build log

The last lines name the failing command and its output.

   ample logs <deployment_id> --kind build

3. 3

Read the runtime log

For health_check_failed the runtime log carries the Spring Boot process output: in the verified run the deliberate boot failure's own error line was there, followed by the platform's health-check verdict and the start command it ran.

   ample logs <deployment_id> --kind runtime

4. 4

Fix and redeploy once

Change the source, the environment or the command override, then run ample deploy again. Do not loop deploys to poll status; an unchanged redeploy is a no-op.

5. 5

Verify

Fetch the live URL on the example; on failure read the build and runtime logs.

   ample logs <deployment_id> --kind build

EXAMPLES

Tested examples

• Spring Boot pattern fixture (tests/deploy-canaries/spring-boot-patterns): Verified deployment diagnostics on Spring Boot.

SUCCESS CHECKS

How to know it worked

• failed deploy reports health_check_failed synchronously
• runtime log carries the app's own error line

LIMITATIONS

Know the limits

• 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.

COST

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.

EVIDENCE

Verification evidence

• canary_run on 2026-09-21T02:23:07Z at revision 50dbac567d2c5cc8e55e6c748a646be0025d9cfb-dirty (CLI 0.1.21): Spring Boot pattern fixture deployed on Ample with CANARY_FAIL=boot (./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 same app deployed with a deliberate boot failure (CANARY_FAIL=boot): ample deploy exited 1 with a coded failure (health_check_failed when the process dies at boot, public_ingress_failed when the framework boots but every request answers 500) and the app's own error line was readable with ample logs <deployment_id> --kind runtime, so the cause is read from the framework's output rather than guessed. (expires 2027-03-20T02:23:07Z)

EXECUTION

Execution binding

No execution binding. This recipe is documentation only; nothing is executed automatically.

NEXT ACTIONS

Typed next actions

• Browse the catalog index (GET /v1/catalog on the api origin; authentication not required, approval not required)
• Search published recipes by intent, stack and constraints (POST /v1/catalog/search on the api origin; authentication not required, approval not required)
• Prepare a side-effect-free deployment plan for an authorized project (POST /v1/catalog/plan on the api origin; authentication required, approval not required)
• Read the existing agent authentication setup (GET /mcp/setup on the api origin; authentication not required, approval not required)
• Browse Spring Boot (GET /v1/catalog/nodes/stack%3Aframework-spring-boot on the api origin; authentication not required, approval not required)
• Browse Troubleshoot deployment (GET /v1/catalog/nodes/intent%3Atroubleshoot-deployment on the api origin; authentication not required, approval not required)
• Browse Public web service (GET /v1/catalog/nodes/pattern%3Apublic-web-service on the api origin; authentication not required, approval not required)
  Actions describe possible next steps. They are typed data, not commands, and grant no permission. Public discovery never provisions anything; planning requires your own authenticated token and approval happens in your client.