#!/usr/bin/env bash

#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.
#

# Usage: start-slave.sh <worker#> <master-spark-URL>
#   where <master-spark-URL> is like "spark://localhost:7077"

bin=`dirname "$0"`
bin=`cd "$bin"; pwd`

# Set SPARK_PUBLIC_DNS so slaves can be linked in master web UI
if [ "$SPARK_PUBLIC_DNS" = "" ]; then
    # If we appear to be running on EC2, use the public address by default:
    # NOTE: ec2-metadata is installed on Amazon Linux AMI. Check based on that and hostname
    if command -v ec2-metadata > /dev/null || [[ `hostname` == *ec2.internal ]]; then
        export SPARK_PUBLIC_DNS=`wget -q -O - http://instance-data.ec2.internal/latest/meta-data/public-hostname`
    fi
fi

"$bin"/spark-daemon.sh start spark.deploy.worker.Worker "$@"