build

#!/usr/bin/env bash
# shellcheck source=/dev/null
. generate-layer.sh
set -eo pipefail

echo "---> Java Buildpack"
#amd64 aarch64
arch=$(dpkg --print-architecture)
if [ "${arch}" == "arm64" ]; then
  arch="aarch64"
fi
# 1. GET ARGS
bp_dir=$(
  cd "$(dirname "$0")"/..
  pwd
)
layers_dir=$1
env_dir="$2/env"
plan_path=$3

# 2. LOAD USER-PROVIDED BUILD-TIME ENVIRONMENT VARIABLES
if compgen -G "${env_dir}"/* >/dev/null; then
  for var in "${env_dir}"/*; do
    declare "$(basename "${var}")=$(<"${var}")"
  done
fi

# 3. INSTALL JAVA
get_jdk_url() {
  if [ "${arch}" == "amd64" ]; then
    local arch="x64"
  fi
  if [ "${version}" == "8" ]; then
    echo "https://github.com/AdoptOpenJDK/openjdk8-upstream-binaries/releases/download/jdk8u292-b10/OpenJDK8U-jdk_${arch}_linux_8u292b10.tar.gz"
  elif [ "${version}" == "11" ]; then
    echo "https://github.com/AdoptOpenJDK/openjdk11-upstream-binaries/releases/download/jdk-11.0.11%2B9/OpenJDK11U-jdk_${arch}_linux_11.0.11_9.tar.gz"
  elif [ "${version}" == "16" ]; then
    echo "https://download.java.net/java/GA/jdk16.0.1/7147401fd7354114ac51ef3e1328291f/9/GPL/openjdk-16.0.1_linux-${arch}_bin.tar.gz"
  elif [ "${version}" == "17" ]; then
    echo "https://download.java.net/java/early_access/jdk17/28/GPL/openjdk-17-ea+28_linux-${arch}_bin.tar.gz"
  elif [ "${version}" == "18" ]; then
    echo "https://download.java.net/java/early_access/jdk18/3/GPL/openjdk-18-ea+3_linux-${arch}_bin.tar.gz"
  else
    echo "${version}"
  fi
}

version=$(yj <"${plan_path}" -t | jq -r '.entries[] | select(.name == "jdk") | .version')
jdk_url="$(get_jdk_url)"

# If it doesn't exist locally, create a JDK cache layer
# This makes JDK available to subsequent buildpacks as well
jdk_layer_dir=${layers_dir}/jdk
if [[ -f "${jdk_layer_dir}.toml" ]]; then
  cached_jdk_url=$(yj <"${jdk_layer_dir}.toml" -t | jq -r .metadata.url 2>/dev/null || echo 'JDK TOML parsing failed')
fi

if [[ "${jdk_url}" != "${cached_jdk_url}" ]]; then
  echo "---> Downloading JDK"
  rm -rf "${layers_dir}"/jdk
  mkdir -p "${layers_dir}"/jdk/env
  wget -q -O - "${jdk_url}" | tar pxz -C "${jdk_layer_dir}" --strip-components=1
  cat >"${jdk_layer_dir}.toml" <<EOF
launch = true
build = true
cache = true
[metadata]
version = "${version}"
EOF

  echo "${layers_dir}"/jdk >"${layers_dir}"/jdk/env/JAVA_HOME
  if [[ -z "${LD_LIBRARY_PATH}" ]]; then
    echo "${JAVA_HOME}/jre/lib/${arch}/server" >"${jdk_layer_dir}/env/LD_LIBRARY_PATH"
  else
    echo "${JAVA_HOME}/jre/lib/${arch}/server:${LD_LIBRARY_PATH}" >"${jdk_layer_dir}"/env/LD_LIBRARY_PATH
  fi

  mkdir -p "${jdk_layer_dir}/profile.d"
  cat >"${jdk_layer_dir}/profile.d/jdk.sh" <<EOF
export JAVA_HOME="${jdk_layer_dir}"
if [[ -z \$LD_LIBRARY_PATH ]]; then
  export LD_LIBRARY_PATH="\$JAVA_HOME/jre/lib/${arch}/server"
else
  export LD_LIBRARY_PATH="\$JAVA_HOME/jre/lib/${arch}/server:${LD_LIBRARY_PATH}"
fi
EOF
fi

# Set env variables to make jdk accessible
for var in "$layers_dir"/jdk/env/*; do
  declare "$(basename "$var")=$(<"$var")"
done
export PATH=${jdk_layer_dir}/bin:$PATH

# 4. MAKE CACHE LAYER, RUN BUILD
# shellcheck disable=SC1090
source "$bp_dir/lib/gradle_build"
# shellcheck disable=SC1090
source "$bp_dir/lib/maven_build"
build_choice="maven"
if [ -f pom.xml ] && [ -f gradlew ]; then
  if [[ -f .build-choice ]]; then
    build_choice=$(tr <.build-choice -d '[:space:]')
  fi
elif [ -f pom.xml ] && [ ! -f gradlew ]; then
  build_choice="maven"
elif [ -f gradlew ] && [ ! -f pom.xml ]; then
  build_choice="gradle"
fi

if [ "${build_choice}" == "maven" ]; then
  maven_build
elif [ "${build_choice}" == "gradle" ]; then
  gradle_build
fi

# 6. SET DEFAULT START COMMAND
if [ -f Procfile ]; then
  generate-launch.sh "${layers_dir}"
else
  target_dir="build/libs"
  # shellcheck disable=SC2044
  for jar_file in $(find "$target_dir" -maxdepth 1 -name "*.jar" -type f); do
    cat >>"${layers_dir}/launch.toml" <<EOL
[[processes]]
type = "web"
command = "java -jar ${jar_file}"
EOL
    break
  done
fi