#!/bin/bash
#

# Copyright (C) 2009 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.

set -e

defaults_file=@SYSCONFDIR@/default/ganeti

# This is a list of all daemons and the order in which they're started. The
# order is important as there are dependencies between them. On shutdown,
# they're stopped in reverse order.
DAEMONS=(
  ganeti-noded
  ganeti-masterd
  ganeti-rapi
  ganeti-confd
  )

NODED_ARGS=
MASTERD_ARGS=
CONFD_ARGS=
RAPI_ARGS=

# Read defaults file if it exists
if [[ -s $defaults_file ]]; then
  . $defaults_file
fi

_daemon_pidfile() {
  echo "@LOCALSTATEDIR@/run/ganeti/$1.pid"
}

_daemon_executable() {
  echo "@PREFIX@/sbin/$1"
}

_daemon_usergroup() {
  case "$1" in
    masterd)
      echo "@GNTMASTERUSER@:@GNTMASTERDGROUP@"
      ;;
    confd)
      echo "@GNTCONFDUSER@:@GNTCONFDGROUP@"
      ;;
    rapi)
      echo "@GNTRAPIUSER@:@GNTRAPIGROUP@"
      ;;
    noded)
      echo "@GNTNODEDUSER@:@GNTDAEMONSGROUP@"
      ;;
    *)
      echo "root:@GNTDAEMONSGROUP@"
      ;;
  esac
}

# Checks whether the local machine is part of a cluster
check_config() {
  local server_pem=@LOCALSTATEDIR@/lib/ganeti/server.pem
  local fname

  for fname in $server_pem; do
    if [[ ! -f $fname ]]; then
      echo "Missing configuration file $fname" >&2
      return 1
    fi
  done

  return 0
}

# Checks the exit code of a daemon
check_exitcode() {
  if [[ "$#" -lt 1 ]]; then
    echo 'Missing exit code.' >&2
    return 1
  fi

  local rc="$1"; shift

  case "$rc" in
    0) ;;
    11)
      echo "not master"
    ;;
    *)
      echo "exit code $rc"
      return 1
    ;;
  esac

  return 0
}

# Prints a list of all daemons in the order in which they should be started
list_start_daemons() {
  local name

  for name in "${DAEMONS[@]}"; do
    echo "$name"
  done
}

# Prints a list of all daemons in the order in which they should be stopped
list_stop_daemons() {
  list_start_daemons | tac
}

# Checks whether a daemon name is known
is_daemon_name() {
  if [[ "$#" -lt 1 ]]; then
    echo 'Missing daemon name.' >&2
    return 1
  fi

  local name="$1"; shift

  for i in "${DAEMONS[@]}"; do
    if [[ "$i" == "$name" ]]; then
      return 0
    fi
  done

  echo "Unknown daemon name '$name'" >&2
  return 1
}

# Checks whether daemon is running
check() {
  if [[ "$#" -lt 1 ]]; then
    echo 'Missing daemon name.' >&2
    return 1
  fi

  local name="$1"; shift

  start-stop-daemon --stop --signal 0 --quiet \
    --pidfile $(_daemon_pidfile $name)
}

# Starts a daemon
start() {
  if [[ "$#" -lt 1 ]]; then
    echo 'Missing daemon name.' >&2
    return 1
  fi

  local name="$1"; shift

  # Convert daemon name to uppercase after removing "ganeti-" prefix
  local plain_name=${name#ganeti-}
  local ucname=$(tr a-z A-Z <<<$plain_name)

  # Read $<daemon>_ARGS and $EXTRA_<daemon>_ARGS
  eval local args="\"\$${ucname}_ARGS \$EXTRA_${ucname}_ARGS\""

  @PKGLIBDIR@/ensure-dirs

  start-stop-daemon --start --quiet --oknodo \
    --pidfile $(_daemon_pidfile $name) \
    --startas $(_daemon_executable $name) \
    --chuid $(_daemon_usergroup $plain_name) \
    -- $args "$@"
}

# Stops a daemon
stop() {
  if [[ "$#" -lt 1 ]]; then
    echo 'Missing daemon name.' >&2
    return 1
  fi

  local name="$1"; shift

  start-stop-daemon --stop --quiet --oknodo --retry 30 \
    --pidfile $(_daemon_pidfile $name)
}

# Starts a daemon if it's not yet running
check_and_start() {
  local name="$1"

  if ! check $name; then
    start $name
  fi
}

# Starts the master role
start_master() {
  start ganeti-masterd
  start ganeti-rapi
}

# Stops the master role
stop_master() {
  stop ganeti-rapi
  stop ganeti-masterd
}

# Start all daemons
start_all() {
  for i in $(list_start_daemons); do
    local rc=0

    # Try to start daemon
    start $i || rc=$?

    if ! errmsg=$(check_exitcode $rc); then
      echo "$errmsg" >&2
      return 1
    fi
  done

  return 0
}

# Stop all daemons
stop_all() {
  for i in $(list_stop_daemons); do
    stop $i
  done
}

# Reloads the SSH keys
reload_ssh_keys() {
  @RPL_SSH_INITD_SCRIPT@ restart
}

if [[ "$#" -lt 1 ]]; then
  echo "Usage: $0 <action>" >&2
  exit 1
fi

orig_action=$1; shift

if [[ "$orig_action" == *_* ]]; then
  echo "Command must not contain underscores" >&2
  exit 1
fi

# Replace all dashes (-) with underlines (_)
action=${orig_action//-/_}

# Is it a known function?
if ! declare -F "$action" >/dev/null 2>&1; then
  echo "Unknown command: $orig_action" >&2
  exit 1
fi

# Call handler function
$action "$@"