build.sh

#!/bin/bash
set -eo pipefail

if [[ -f /etc/environment_proxy ]]; then
	source /etc/environment_proxy
fi

if [[ "$1" == "-" ]]; then
    slug_file="$1"
else
    slug_file=/tmp/slug.tgz
    if [[ "$1" ]]; then
        put_url="$1"
    fi
fi


app_dir=/app
build_root=/tmp/build
cache_root=/tmp/cache
buildpack_root=/tmp/buildpacks

mkdir -p $app_dir
mkdir -p $cache_root
mkdir -p $buildpack_root
mkdir -p $build_root/.profile.d

function output_redirect() {
    if [[ "$slug_file" == "-" ]]; then
        cat - 1>&2
    else
        cat -
    fi
}

function echo_title() {
    echo $'\e[1G----->' $* | output_redirect
}

function echo_normal() {
    echo $'\e[1G      ' $* | output_redirect
}

function ensure_indent() {
    while read line; do
        if [[ "$line" == --* ]]; then
            echo $'\e[1G'$line | output_redirect
        else
            echo $'\e[1G      ' "$line" | output_redirect
        fi
    done
}

## Copy application code over
if [ -d "/tmp/app" ]; then
    cp -rf /tmp/app/. $app_dir
else
    cat | tar -xmC $app_dir
fi

# In heroku, there are two separate directories, and some
# buildpacks expect that.
cp -r $app_dir/. $build_root

## Buildpack fixes

export APP_DIR="$app_dir"
export HOME="$app_dir"
export REQUEST_ID=$(openssl rand -base64 32)
export STACK=cedar-14

## Buildpack detection

buildpacks=($buildpack_root/*)
selected_buildpack=

if [[ -n "$BUILDPACK_URL" ]]; then
    echo_title "Fetching custom buildpack"

    buildpack="$buildpack_root/custom"
    rm -fr "$buildpack"
    git clone --quiet --depth=1 "$BUILDPACK_URL" "$buildpack"
    selected_buildpack="$buildpack"
    buildpack_name=$($buildpack/bin/detect "$build_root") && selected_buildpack=$buildpack
else
    for buildpack in "${buildpacks[@]}"; do
        buildpack_name=$($buildpack/bin/detect "$build_root") && selected_buildpack=$buildpack && break
    done
fi

if [[ -n "$selected_buildpack" ]]; then
    echo_title "$buildpack_name app detected"
    else
    echo_title "Unable to select a buildpack"
    exit 1
fi

## Buildpack compile

$selected_buildpack/bin/compile "$build_root" "$cache_root" | ensure_indent

$selected_buildpack/bin/release "$build_root" "$cache_root" > $build_root/.release

## Display process types

echo_title "Discovering process types"
if [[ -f "$build_root/Procfile" ]]; then
    types=$(ruby -e "require 'yaml';puts YAML.load_file('$build_root/Procfile').keys().join(', ')")
    echo_normal "Procfile declares types -> $types"
fi
default_types=""
if [[ -s "$build_root/.release" ]]; then
    default_types=$(ruby -e "require 'yaml';puts (YAML.load_file('$build_root/.release')['default_process_types'] || {}).keys().join(', ')")
    [[ $default_types ]] && echo_normal "Default process types for $buildpack_name -> $default_types"
fi


## Produce slug

if [[ -f "$build_root/.slugignore" ]]; then
    tar -z --exclude='.git' -X "$build_root/.slugignore" -C $build_root -cf $slug_file . | cat
else
    tar -z --exclude='.git' -C $build_root -cf $slug_file . | cat
fi

if [[ "$slug_file" != "-" ]]; then
    slug_size=$(du -Sh "$slug_file" | cut -f1)
    echo_title "Compiled slug size is $slug_size"

    if [[ $put_url ]]; then
        curl -0 -s -o /dev/null -X PUT -T $slug_file "$put_url"
    fi
fi