#!/bin/sh

###############################################################################
#  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.
###############################################################################

# If unspecified, the hostname of the container is taken as the JobManager address
JOB_MANAGER_RPC_ADDRESS=${JOB_MANAGER_RPC_ADDRESS:-$(hostname -f)}
CONF_FILE="${FLINK_HOME}/conf/flink-conf.yaml"

drop_privs_cmd() {
    if [ $(id -u) != 0 ]; then
        # Don't need to drop privs if EUID != 0
        return
    elif [ -x /sbin/su-exec ]; then
        # Alpine
        echo su-exec flink
    else
        # Others
        echo gosu flink
    fi
}

copy_plugins_if_required() {
  if [ -z "$ENABLE_BUILT_IN_PLUGINS" ]; then
    return 0
  fi

  echo "Enabling required built-in plugins"
  for target_plugin in $(echo "$ENABLE_BUILT_IN_PLUGINS" | tr ';' ' '); do
    echo "Linking ${target_plugin} to plugin directory"
    plugin_name=${target_plugin%.jar}

    mkdir -p "${FLINK_HOME}/plugins/${plugin_name}"
    if [ ! -e "${FLINK_HOME}/opt/${target_plugin}" ]; then
      echo "Plugin ${target_plugin} does not exist. Exiting."
      exit 1
    else
      ln -fs "${FLINK_HOME}/opt/${target_plugin}" "${FLINK_HOME}/plugins/${plugin_name}"
      echo "Successfully enabled ${target_plugin}"
    fi
  done
}

set_config_option() {
  local option=$1
  local value=$2

  # escape periods for usage in regular expressions
  local escaped_option=$(echo ${option} | sed -e "s/\./\\\./g")

  # either override an existing entry, or append a new one
  if grep -E "^${escaped_option}:.*" "${CONF_FILE}" > /dev/null; then
        sed -i -e "s/${escaped_option}:.*/$option: $value/g" "${CONF_FILE}"
  else
        echo "${option}: ${value}" >> "${CONF_FILE}"
  fi
}

set_common_options() {
    set_config_option jobmanager.rpc.address ${JOB_MANAGER_RPC_ADDRESS}
    set_config_option blob.server.port 6124
    set_config_option query.server.port 6125
}

if [ "$1" = "help" ]; then
    echo "Usage: $(basename "$0") (jobmanager|taskmanager|help)"
    exit 0
elif [ "$1" = "jobmanager" ]; then
    shift 1
    echo "Starting Job Manager"
    copy_plugins_if_required

    set_common_options

    if [ -n "${FLINK_PROPERTIES}" ]; then
        echo "${FLINK_PROPERTIES}" >> "${CONF_FILE}"
    fi
    envsubst < "${CONF_FILE}" > "${CONF_FILE}.tmp" && mv "${CONF_FILE}.tmp" "${CONF_FILE}"

    exec $(drop_privs_cmd) "$FLINK_HOME/bin/jobmanager.sh" start-foreground "$@"
elif [ "$1" = "taskmanager" ]; then
    shift 1
    echo "Starting Task Manager"
    copy_plugins_if_required

    TASK_MANAGER_NUMBER_OF_TASK_SLOTS=${TASK_MANAGER_NUMBER_OF_TASK_SLOTS:-$(grep -c ^processor /proc/cpuinfo)}

    set_common_options
    set_config_option taskmanager.numberOfTaskSlots ${TASK_MANAGER_NUMBER_OF_TASK_SLOTS}

    if [ -n "${FLINK_PROPERTIES}" ]; then
        echo "${FLINK_PROPERTIES}" >> "${CONF_FILE}"
    fi
    envsubst < "${CONF_FILE}" > "${CONF_FILE}.tmp" && mv "${CONF_FILE}.tmp" "${CONF_FILE}"

    exec $(drop_privs_cmd) "$FLINK_HOME/bin/taskmanager.sh" start-foreground "$@"
fi

exec "$@"