#!/usr/bin/env bash

# Copyright 2015 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Wait for a file to exist in the filesystem.
# Block up to the timeout duration in seconds (default: 10).
# Usage: await-file [-t=<duration>] <address>
# Requires: timeout, file

set -o errexit
set -o nounset
set -o pipefail

duration=10
if [[ "${1:-}" == "-t="* ]]; then
    duration="${1:3}"
    [ -z "${duration}" ] && echo "Invalid duration supplied" && exit 1
    shift
fi

file="$1"
[ -z "$file" ] && echo "No file supplied" && exit 1

echo "Waiting (up to ${duration}s) for ${file} to exist"
if ! timeout "${duration}" bash -c "while [ ! -f \"${file}\" ]; do sleep 0.5; done"; then
    echo "Timed out"
    exit 1
fi

echo "File ${file} exists now!"