#
# NOTE: THIS DOCKERFILE IS GENERATED VIA "update.sh"
#
# PLEASE DO NOT EDIT IT DIRECTLY.
#

FROM buildpack-deps:xenial-scm

# A few reasons for installing distribution-provided OpenJDK:
#
#  1. Oracle.  Licensing prevents us from redistributing the official JDK.
#
#  2. Compiling OpenJDK also requires the JDK to be installed, and it gets
#     really hairy.
#
#     For some sample build times, see Debian's buildd logs:
#       https://buildd.debian.org/status/logs.php?pkg=openjdk-9

RUN apt-get update && apt-get install -y --no-install-recommends \
		bzip2 \
		unzip \
		xz-utils \
	&& rm -rf /var/lib/apt/lists/*

# Default to UTF-8 file.encoding
ENV LANG C.UTF-8

# add a simple script that can auto-detect the appropriate JAVA_HOME value
# based on whether the JDK or only the JRE is installed
RUN { \
		echo '#!/bin/sh'; \
		echo 'set -e'; \
		echo; \
		echo 'dirname "$(dirname "$(readlink -f "$(which javac || which java)")")"'; \
	} > /usr/local/bin/docker-java-home \
	&& chmod +x /usr/local/bin/docker-java-home

# do some fancy footwork to create a JAVA_HOME that's cross-architecture-safe
RUN ln -svT "/usr/lib/jvm/java-9-openjdk-$(dpkg --print-architecture)" /docker-java-home
ENV JAVA_HOME /docker-java-home

RUN set -ex; \
	\
# deal with slim variants not having man page directories (which causes "update-alternatives" to fail)
	if [ ! -d /usr/share/man/man1 ]; then \
		mkdir -p /usr/share/man/man1; \
	fi; \
	\
	apt-get update; \
	apt-get install -y --no-install-recommends \
		openjdk-9-jdk \
	; \
	rm -rf /var/lib/apt/lists/*; \
	\
# verify that "docker-java-home" returns what we expect
	[ "$(readlink -f "$JAVA_HOME")" = "$(docker-java-home)" ]; \
	\
# update-alternatives so that future installs of other OpenJDK versions don't change /usr/bin/java
	update-alternatives --get-selections | awk -v home="$(readlink -f "$JAVA_HOME")" 'index($3, home) == 1 { $2 = "manual"; print | "update-alternatives --set-selections" }'; \
# ... and verify that it actually worked for one of the alternatives we care about
	update-alternatives --query java | grep -q 'Status: manual'

# https://docs.oracle.com/javase/9/tools/jshell.htm
# https://en.wikipedia.org/wiki/JShell
CMD ["jshell"]

# If you're reading this and have any feedback on how this image could be
# improved, please open an issue or a pull request so we can discuss it!
#
#   https://github.com/docker-library/openjdk/issues
