Dockerfile

# syntax=docker/dockerfile:1

########################################
# Stage 1 — build the application with Maven
########################################
FROM maven:3.9.9-eclipse-temurin-17 AS build
WORKDIR /build

# Cache dependencies separately from source so `docker build` doesn't
# re-download the whole internet every time a .java file changes.
COPY pom.xml .
RUN mvn -B -q dependency:go-offline

COPY src ./src

# Runs the full JUnit/Mockito suite (none of it needs a live database,
# see PostgresConnectionTest) and produces the shaded, self-contained
# target/library-console.jar (main class + postgresql driver bundled).
RUN mvn -B -q clean package

########################################
# Stage 2 — runtime image
########################################
# The UI (LanternaScreens) always opens a real Swing window
# (factory.setPreferTerminalEmulator(true)), so a plain headless JRE
# is not enough — the container needs a virtual X display. We start
# Xvfb + a tiny window manager + x11vnc + noVNC, so the app's window
# can be viewed and clicked from any web browser at http://host:6080.
FROM eclipse-temurin:17-jre-jammy

RUN apt-get update \
    && apt-get install -y --no-install-recommends \
        xvfb \
        x11vnc \
        fluxbox \
        novnc \
        websockify \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app
COPY --from=build /build/target/library-console.jar ./library-console.jar
COPY docker/entrypoint.sh /entrypoint.sh
RUN chmod +x /entrypoint.sh

# Sensible defaults; override at `docker run`/compose time.
ENV LIBRARY_DB_URL=jdbc:postgresql://db:5432/library \
    LIBRARY_DB_USER=postgres \
    LIBRARY_DB_PASSWORD=admin1 \
    DISPLAY=:99 \
    SCREEN_RESOLUTION=1280x800x24 \
    VNC_PORT=5900 \
    NOVNC_PORT=6080

# noVNC (browser access) and raw VNC (for a native VNC client), respectively.
EXPOSE 6080 5900

ENTRYPOINT ["/entrypoint.sh"]