# 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.
HADOOP_NAME="datanode"
DAEMON="hadoop-hdfs-$HADOOP_NAME"
DESC="Hadoop $HADOOP_NAME"
EXEC_PATH="/usr/lib/hadoop/sbin/hadoop-daemon.sh"
SVC_USER="hdfs"
DAEMON_FLAGS="$HADOOP_NAME"
CONF_DIR="/etc/hadoop/conf"
PIDFILE="/var/run/hadoop-hdfs/hadoop-$SVC_USER-$HADOOP_NAME.pid"
LOCKDIR="/var/lock/subsys"
LOCKFILE="hadoop-$HADOOP_NAME"

generate_start() {

cat <<'__EOT__'
start() {
  [ -x $EXEC_PATH ] || exit $ERROR_PROGRAM_NOT_INSTALLED
  [ -d $CONF_DIR ] || exit $ERROR_PROGRAM_NOT_CONFIGURED
  log_success_msg "Starting ${DESC}: "

  TARGET_USER_NAME="HADOOP_`echo datanode | tr a-z A-Z`_USER"
  TARGET_USER=$(eval "echo \$$TARGET_USER_NAME")

  # The following needs to be removed once HDFS-1943 gets finally put to rest.
  # The logic of this ugly hack is this: IFF we do NOT have jsvc installed it is
  # guaranteed that we can NOT be running in a secure mode and thus we need to
  # workaround HDFS-1943 (start as non-root). As soon as jsvc gets installed
  # we are assuming a secure installation and starting a data node as root.
  # This leaves 2 corner cases:
  #    1. HADOOP_DATANODE_USER being set to root
  #    2. jsvc is installed but Hadoop is configures to run in an unsecure mode
  # Both will currently fail
  if [ -n "$HADOOP_SECURE_DN_USER" ]; then
    TARGET_USER=root
  fi

  export HADOOP_IDENT_STRING=$TARGET_USER
  su -s /bin/bash $TARGET_USER -c "$EXEC_PATH --config '$CONF_DIR' start $DAEMON_FLAGS"

  # Some processes are slow to start
  sleep $SLEEP_TIME
  checkstatusofproc
  RETVAL=$?

  [ $RETVAL -eq $RETVAL_SUCCESS ] && touch $LOCKFILE
  return $RETVAL
}
__EOT__

}