Dockerfile

# See https://docs.docker.com/engine/userguide/eng-image/multistage-build/
# First build the app on a maven open jdk 11 container
FROM maven:3.8.6-openjdk-11 as app-builder

COPY . /build/veraPDF-rest

WORKDIR /build/veraPDF-rest
RUN mvn clean package

# Install dumb-init for process safety
# https://github.com/Yelp/dumb-init
RUN wget -O /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.5/dumb-init_1.2.5_x86_64

# Now build a Java JRE for the Alpine application image
# https://github.com/docker-library/docs/blob/master/eclipse-temurin/README.md#creating-a-jre-using-jlink
FROM eclipse-temurin:11 as jre-builder

# Create a custom Java runtime
RUN "$JAVA_HOME/bin/jlink" \
    --add-modules java.base,java.logging,java.xml,java.management,java.sql,java.desktop,jdk.crypto.ec \
    --strip-debug \
    --no-man-pages \
    --no-header-files \
    --compress=2 \
    --output /javaruntime

# Now the final application image
FROM debian:bullseye-slim

RUN apt-get update && apt-get install -y curl && rm -rf /var/lib/apt/lists/*

# Set for additional arguments passed to the java run command, no default
ARG JAVA_OPTS
ENV JAVA_OPTS=$JAVA_OPTS
# Specify the veraPDF REST version if you want to (to be used in build automation), default is 0.1.0-SNAPSHOT
ARG VERAPDF_REST_VERSION
ENV VERAPDF_REST_VERSION=${VERAPDF_REST_VERSION:-0.2.0-SNAPSHOT}

COPY --from=app-builder /usr/local/bin/dumb-init /usr/local/bin/dumb-init
RUN chmod +x /usr/local/bin/dumb-init

# Copy the JRE from the previous stage
ENV JAVA_HOME=/opt/java/openjdk
ENV PATH "${JAVA_HOME}/bin:${PATH}"
COPY --from=jre-builder /javaruntime $JAVA_HOME

# Since this is a running network service we'll create an unprivileged account
# which will be used to perform the rest of the work and run the actual service:
RUN useradd --system --user-group --home-dir=/opt/verapdf-rest verapdf-rest
RUN mkdir --parents /var/opt/verapdf-rest/logs && chown -R verapdf-rest:verapdf-rest /var/opt/verapdf-rest

USER verapdf-rest
WORKDIR /opt/verapdf-rest

# Copy the application from the previous stage
COPY --from=app-builder /build/veraPDF-rest/target/verapdf-rest-${VERAPDF_REST_VERSION}.jar /opt/verapdf-rest/
# Copy the default configuration file
COPY --from=app-builder /build/veraPDF-rest/server.yml /var/opt/verapdf-rest/config/
COPY --from=app-builder /build/veraPDF-rest/config /opt/verapdf-rest/config/

VOLUME /var/opt/verapdf-rest
EXPOSE 8080

ENTRYPOINT dumb-init java $JAVA_OPTS -Djava.awt.headless=true -jar /opt/verapdf-rest/verapdf-rest-${VERAPDF_REST_VERSION}.jar server /var/opt/verapdf-rest/config/server.yml