Spring Boot Dockerfile generator

Good practice: Multi-stage build (2 stages)

Compilers, dev dependencies and source files stay in the build stages. Only the runtime artefacts are copied into the final image.

Good practice: Runs as spring, not root

A container escape from a root process is a host root process. Dropping privileges is the cheapest hardening step there is.

Good practice: .dockerignore keeps secrets out of the build context

`.git`, `.env` and local dependency folders never reach the daemon, so they cannot end up in a layer or in `docker history`.

Good practice: Dependency cache persists across builds

BuildKit cache mounts keep the package manager store outside the image. Rebuilds after a lockfile change reuse everything already downloaded, and the cache adds nothing to the final size.

Good practice: Healthcheck defined

Docker, Compose and Easypanel can tell the difference between a running process and a working app, and restart it when it wedges.

Good practice: The JVM respects the container memory limit

MaxRAMPercentage sizes the heap against the cgroup limit, not the host's total RAM. Without it the JVM sees the whole machine and gets OOM-killed the moment the limit is enforced.

Good practice: Dependencies and code are separate layers

A code-only change re-pushes a few hundred kilobytes instead of the whole fat jar. Requires Spring Boot 3.3 or later for the `-Djarmode=tools` syntax.

Note: Requires BuildKit

BuildKit is the default builder in Docker 23 and later. On anything older, export `DOCKER_BUILDKIT=1` before building.

Note: The healthcheck needs Actuator

It probes /actuator/health. Add spring-boot-starter-actuator, or point the probe at an endpoint you already expose.