a gradle dockerfile containing multiple best practices

Dockerfile

ARG DOCKER_REGISTRY=index.docker.io
FROM $DOCKER_REGISTRY/library/gradle:8.9.0-jdk21-alpine AS base

RUN mkdir -p /root/.gradle
RUN echo "org.gradle.daemon=false" >> /root/.gradle/gradle.properties
RUN echo "org.gradle.caching=true" >> /root/.gradle/gradle.properties
RUN echo "org.gradle.configuration-cache=true" >> /root/.gradle/gradle.properties

WORKDIR /app

COPY build.gradle \
    settings.gradle \
    gradlew \
    ./
COPY gradle gradle

RUN \
	--mount=type=secret,id=initgradle,target=/root/.gradle/init.gradle \
	--mount=type=secret,id=ARTIFACTORY_TOKEN \
	--mount=type=cache,id=gradle-caches,target=/root/.gradle/caches,sharing=private \
	--mount=type=cache,id=gradle-configuration-cache,target=/app/.gradle/configuration-cache,sharing=private \
	gradle --write-verification-metadata sha256 help \
        && rm gradle/verification-metadata.xml

# persist the current gradle cache to disk for registry caching
RUN \
	--mount=type=cache,id=gradle-caches,target=/gradle-caches,sharing=private \
	cp -r /gradle-caches /root/.gradle/caches

FROM base AS build

COPY src src

RUN \
	--mount=type=secret,id=initgradle,target=/root/.gradle/init.gradle \
	--mount=type=secret,id=ARTIFACTORY_TOKEN \
	--mount=type=cache,id=gradle-caches,target=/root/.gradle/caches,sharing=private,from=base,source=/root/.gradle/caches \
	--mount=type=cache,id=gradle-configuration-cache,target=/app/.gradle/configuration-cache,sharing=private \
	gradle build -x test

FROM build AS test
RUN \
	--mount=type=secret,id=initgradle,target=/root/.gradle/init.gradle \
	--mount=type=secret,id=ARTIFACTORY_TOKEN \
	--mount=type=cache,id=gradle-caches,target=/root/.gradle/caches,sharing=private,from=base,source=/root/.gradle/caches \
	--mount=type=cache,id=gradle-configuration-cache,target=/app/.gradle/configuration-cache,sharing=private \
	gradle test