Diagnose deployment failures for Spring Boot

Deployment diagnostics for a Spring Boot app on Ample. Verified on Spring Boot: 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 --kind runtime, so the cause is read from the framework's output rather than guessed. Build and start:

./mvnw -q -DskipTests package  # (or the Gradle wrapper)
java -jar on the jvm-21 template (Temurin JDK 21) with server.port read from PORT.

Representative Queries

• Diagnose deployment failures for Spring Boot
• Where can I host Diagnose deployment failures built with Spring Boot?
• I need framework-specific failure signatures and validation checks using only actual available observability interfaces.

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)
• An Ample account token with servers:write

Workflow Steps

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. Read the build log
   The last lines name the failing command and its output. Command: ample logs --kind build

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. Command: ample logs --kind runtime

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. Verify
   Fetch the live URL on the example; on failure read the build and runtime logs. Command: ample logs --kind build

Examples

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

Success Checks

• Failed deploy reports health_check_failed synchronously
  Expect: ample deploy exits 1 with error.code health_check_failed
• Runtime log carries the app's own error line
  Expect: ample logs --kind runtime shows the framework's error output before the health-check verdict

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.

Cost Estimate

• Currency: USD
• Monthly Amount: 5.0
• Basis: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
• Components:
  • Name: app server
    Size: s-1vcpu-1gb
    Quantity: 1.0
    Monthly Amount: 5.0
• Note: Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.

Evidence Summary

• Canary Run
  Summary: Spring Boot pattern fixture deployed on Ample with CANARY_FAIL=boot. The deliberate boot failure's error line was readable from the framework's output rather than guessed. Observed At: 2026-09-21T02:23:07Z

Formats

• HTML Documentation
• Markdown Documentation
• JSON Documentation

Next Actions

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