generate self-contained, executable app archives

slugger

#!/bin/bash

trim() {
    local var="$*"
    var="${var#"${var%%[![:space:]]*}"}"
    echo -n "${var%"${var##*[![:space:]]}"}"
}

parseprocfile() {
    local IFS=":"
    while read -r name cmd; do
        echo "$(trim "$name")" "$(trim "$cmd")"
    done <<< "$(grep -v "^\s*$" "$1")"
}

writehead() {
    cat << "EOF" > "$1"
#!/bin/bash
pushd "$(dirname $0)" > /dev/null
  dir="$(pwd)"
  bin="$dir/$(basename $0)"
popd > /dev/null
end="$(awk '/^ENDSCRIPT/ { print NR + 1; exit 0; }' "$bin")"
EOF
}

writecmds() {
    echo 'case "$1" in' >> "$1"
    while read -r name cmd; do
        echo "  \"$name\") exec $cmd;;" >> "$1"
    done <<< "$(parseprocfile Procfile)"
    echo '  *) echo "unknown command: \"$1\"" >&2;;' >> "$1"
    echo 'esac' >> "$1"
}

writebody() {
    cat << "EOF" >> "$1"
rm -rf extract
mkdir extract
tail -n +"$end" "$bin" | tar -zx -C extract
test -d extract/.venv && source extract/.venv/bin/activate
EOF
writecmds "$1"
echo 'exit 1' >> "$1"
}

writetail() {
    echo "ENDSCRIPT" >> "$2"
    git archive "$1" | gzip >> "$2"
}

out="run"
ref="HEAD"
while getopts "o:r:" opt; do
    case "$opt" in
        o) out="$OPTARG";;
        r) ref="$OPTARG";;
    esac
done
shift $(( $OPTIND - 1 ))
dir="${1:-.}"
pushd "$dir" > /dev/null
    writehead "$out"
    writebody "$out"
    writetail "$ref" "$out"
    chmod +x "$out"
popd > /dev/null

using slugger

$ slugger -o run .
$ PORT=5678 ./run web
[2015-09-13 02:50:32 -0400] [24411] [INFO] Starting gunicorn 19.3.0
[2015-09-13 02:50:32 -0400] [24411] [INFO] Listening at: http://127.0.0.1:5678 (24411)
[2015-09-13 02:50:32 -0400] [24411] [INFO] Using worker: sync
[2015-09-13 02:50:32 -0400] [24426] [INFO] Booting worker with pid: 24426