Ubuntu Chiseled JRE image (based on OpenJDK) with Springboot Petclinic sample app

Dockerfile

ARG UBUNTU_RELEASE=24.04
ARG CHISEL_VERSION=v1.1.0


FROM eclipse-temurin:21-jdk-noble AS build
ADD https://github.com/spring-projects/spring-petclinic.git /app
WORKDIR /app
RUN ./mvnw package


FROM ubuntu:$UBUNTU_RELEASE AS builder
ARG TARGETARCH UBUNTU_RELEASE CHISEL_VERSION
SHELL ["/bin/bash", "-oeux", "pipefail", "-c"]

RUN apt-get update \
    && DEBIAN_FRONTEND=noninteractive apt-get install -y ca-certificates

ADD "https://github.com/canonical/chisel/releases/download/${CHISEL_VERSION}/chisel_${CHISEL_VERSION}_linux_${TARGETARCH}.tar.gz" \
    chisel.tar.gz

RUN tar -xvf chisel.tar.gz -C /usr/bin/

RUN apt-get install -y git file  # file is needed by the chisel-wrapper script
RUN git clone --depth 1 -b main https://github.com/canonical/rocks-toolbox /rocks-toolbox && mv /rocks-toolbox/chisel-wrapper /usr/local/bin/ && rm -rf /rocks-toolbox
RUN mkdir -p /staging-rootfs/var/lib/dpkg

RUN chisel-wrapper --generate-dpkg-status /staging-rootfs/var/lib/dpkg/status -- --release "ubuntu-$UBUNTU_RELEASE" --root /staging-rootfs \
        base-files_base \
        base-files_release-info \
        base-files_chisel \
        openjdk-21-jre-headless_standard

RUN cp /etc/passwd /etc/group /staging-rootfs/etc \
    && install -o ubuntu -g ubuntu -d /staging-rootfs/home/ubuntu


FROM scratch
COPY --from=builder /staging-rootfs /
USER ubuntu
WORKDIR /home/ubuntu
# Note: the * wildcard resolves the concrete filename which changes over time, e.g. "spring-petclinic-3.4.0-SNAPSHOT.jar"
COPY --from=build /app/target/spring-petclinic-*.jar /app/app.jar
ARG TARGETARCH
ENV PATH="$PATH:/usr/lib/jvm/java-21-openjdk-${TARGETARCH}/bin"
ENTRYPOINT ["java", "-jar", "/app/app.jar"]