Spring Boot file-tree tests: prove binding without claiming secret delivery

What the child process checks

RelaySettingsProcessTest now launches a child JVM with a real file tree, an environment override, an absent required directory and an out-of-range file value. It also checks a two-hop relative import and an extensionless properties file. These tests cover concrete startup paths under the pinned source-kit version. The file-binding page states the successful case; the missing-location page states one failure case.

The fixture does not create a container, attach a secret volume, change the Unix user, or start ReceiptApplication. It does not prove that a deployment manifest points at the right mount or that the application can read it after a rollout.

Design the deployment check

Start the packaged application with the actual entrypoint, user identity, working directory and mount. Use non-secret sentinel settings to check path resolution and source precedence. For a credential, check presence and behavior through a safe authenticated operation; do not echo its bytes or return them from an Actuator endpoint.

Exercise missing mount, invalid value and restored mount as separate deployments. Confirm readiness and traffic behavior; a child exit alone does not test an ingress controller. Health groups and termination order describe those distinct states.

Checked source

// Local proof: configtree directory + child JVM + non-secret bound values.
// Deployment proof still needed: real mount + identity + packaged app + readiness.

Verification boundary

RelaySettingsProcessTest (twelve child-JVM cases). The full fixture is in the downloadable source kit.

Common Mistakes

• Do not describe a temporary directory as a secret mount.
• Do not log credentials to prove a configtree import.
• Do not substitute a process-exit check for deployment readiness and ingress tests.

Read next

Spring Boot configtree: bind one file per property in a child JVM, Spring Boot required configtree: reject an absent directory, Spring Boot config tests: what a child JVM proves and what deployment still owes, Spring Boot liveness versus readiness: do not restart on every dependency outage.