Mongo DB init script for Linux and OSX

mongod

#!/bin/bash

# Nasty, intentionally verbose script to start/stop mongod
# Mark Woods - March 2010

RUNTIME_USER='nobody' # only applicable on Linux, otherwise runs as current user
LOGPATH='/var/log/mongodb/mongod.log'
CONFIGFILE='/etc/mongod.conf'
DBPATH='/opt/mongodb/data/db'
BINPATH='/opt/mongodb/bin/mongod'
PSCMD='ps aux | egrep "bin/[m]ongod" > /dev/null 2>&1'
STARTCMD="$BINPATH --fork --dbpath $DBPATH --logpath $LOGPATH --logappend"
REPAIRCMD="$BINPATH --repair --dbpath $DBPATH"
STOPCMD='killall -2 mongod'
KILLCMD='killall -9 mongod'
RETVAL=0

# use optional config file if exists
if [ -f $CONFIGFILE ]; then
  STARTCMD="$STARTCMD -f $CONFIGFILE"
fi

mongod_set_runtime_user_and_check_paths() {
  CURRENT_USER=`whoami`
  if [ `uname` = "Linux" ]; then
    # run as configured runtime user if Linux (I don't know how to do this in BSD/OSX)
    if [ ! $CURRENT_USER = 'root' ]; then
      echo "WARNING: cannot set runtime user for mongod because you are not root, mongod will run under user $CURRENT_USER"
      RUNTIME_USER=$CURRENT_USER
      RUNTIME_GROUP=`id -gn $CURRENT_USER`
    else
      RUNTIME_GROUP=`id -gn $RUNTIME_USER`
      if [ ! $? -eq 0  ]; then
        echo "WARNING: runtime user $RUNTIME_USER does not exist, setting to nobody"
        RUNTIME_USER='nobody'
        RUNTIME_GROUP=`id -gn $RUNTIME_USER` 
      fi
      STARTCMD="su $RUNTIME_USER -c '$STARTCMD'"
    fi
  else
    RUNTIME_USER=$CURRENT_USER
    RUNTIME_GROUP=`id -gn $CURRENT_USER`
  fi

  if [ ! -d $DBPATH ]; then
    echo "WARNING: dbpath $DBPATH does not exist"
    if [ $CURRENT_USER = "root" ]; then
      echo "Creating dbpath $DBPATH..."
      mkdir -p $DBPATH
      chmod 750 $DBPATH
      chown -R $RUNTIME_USER:$RUNTIME_GROUP $DBPATH
    fi
  fi
  
  if [ $CURRENT_USER = "root" ]; then
    chown -R $RUNTIME_USER:$RUNTIME_GROUP $DBPATH # brutal, but effective
  fi

  LOGDIR=`dirname $LOGPATH`
  if [ ! -d $LOGDIR ]; then
    echo "WARNING: log directory $LOGDIR doesn't exist"
    if [ $CURRENT_USER = "root" ]; then
      echo "Creating log directory $LOGDIR..."
      mkdir -p $LOGDIR
      chmod 750 $LOGDIR
      chown -R $RUNTIME_USER:$RUNTIME_GROUP $LOGDIR
    fi
  else
    if [ `uname` = "Linux" ] && [ $CURRENT_USER = "root" ]; then
      TOUCHCMD="su $RUNTIME_USER -c 'touch $LOGPATH > /dev/null 2>&1'"
    else
      TOUCHCMD="touch $LOGPATH > /dev/null 2>&1"
    fi
    eval $TOUCHCMD
    if [ ! $? -eq 0 ]; then
      echo "WARNING: cannot write to log file $LOGPATH"
    fi
  fi
}

mongod_running() {
  eval $PSCMD
  if [ $? -eq 0 ]; then
    IS_RUNNING="true"
  else
    IS_RUNNING="false"
  fi  
}

mongod_start() {
  
  mongod_running
  
  if [ "$IS_RUNNING" = "true" ]; then
    echo "Mongod is already running"
    echo exiting
    exit 2
  fi
  
  mongod_set_runtime_user_and_check_paths
  
  echo "Starting mongod..."
  eval $STARTCMD
  RETVAL=$?
  
  if [ ! $RETVAL -eq 0 ]; then
    echo "ERROR: Mongod failed to start"
    echo "Check that user $RUNTIME_USER can write to dbpath $DBPATH and logpath $LOGPATH"
    echo "If that doesn't help, check the log file at $LOGPATH"
  else
    sleep 3
    mongod_running
    if [ "$IS_RUNNING" = "false" ]; then
      echo "WARNING: Mongod has not yet started, please wait..."
      sleep 5
      mongod_running
      if [ "$IS_RUNNING" = "false" ]; then
          echo "ERROR: Mongod hasn't started"
          echo "Check that user $RUNTIME_USER can write to dbpath $DBPATH and logpath $LOGPATH"
          echo "If that doesn't help, check the log file at $LOGPATH"
          exit 2
      fi
    fi
  fi
  
}

mongod_stop() {

  mongod_running
  
  if [ "$IS_RUNNING" = "false" ]; then
    echo "Mongod does not seem to be running"
    return
  fi
  
  echo "Stopping mongod..."
  eval $STOPCMD
  RETVAL=$?

  if [ ! $RETVAL -eq 0 ]; then
    if [ `whoami` = "root" ]; then
      echo "Mongod failed to shut down"
    else
      echo "Mongod failed to shut down, this might be just because you don't have permission to stop it"
    fi
    echo "The log file at $LOGPATH may contain more information"
    echo "If you need to send the KILL signal to the process, you MUST repair all databases afterwards by running: $0 repair"
    exit $RETVAL
  else
    sleep 5
    mongod_running
    if [ "$IS_RUNNING" = "true" ]; then
      echo "Mongod has not yet shut down properly, please wait and do NOT kill the process!"
      sleep 15
      mongod_running
      if [ "$IS_RUNNING" = "true" ]; then
        echo "Mongod still hasn't shut down properly..."
        if [ `whoami` = "root" ]; then
          echo "This is probably because some database operation that hasn't completed is preventing the server from shutting down"
        else
          echo "This might be just because you don't have permission to stop it, or it could be that some database operation that hasn't completed is preventing the server from shutting down"
        fi
        echo "You can use the mongo shell to show and kill running operataions - see db.currentOP() and db.killOP()"
        echo "If you need to send the KILL signal to the process, you MUST repair all databases afterwards by running: $0 repair"
        exit 2
      fi
    fi
  fi
    
}

mongod_repair() {
 
  # check that there is sufficient disk space to run a repair...
  # note: choice of tools used to determine free and used space based on compatibility between linux and bsd/osx
  FREE_GIGABYTES=`df -h / | sed '1,1d' | awk '{ print $4 }' | sed 's/[^0-9]\.//g'` # FIXME: assumes mongo is on root partition
  USED_GIGABYTES=$((`ls -lk $DBPATH | head -1 | cut -d' ' -f2`/1048576))
  REQUIRED_GIGABYTES=$((USED_GIGABYTES+5)) # add an extra 5 gigs to allow for some other process chewing up disk space while repair runs
  
  if [ `echo "$REQUIRED_GIGABYTES < $FREE_GIGABYTES" | bc` -eq 0 ]; then
    echo "Not enough disk space to run repair (${FREE_GIGABYTES}G free, but need ${REQUIRED_GIGABYTES}G), exiting..." 1>&2
    exit 1
  fi

  mongod_running
  
  if [ "$IS_RUNNING" = "true" ]; then
    echo "Mongod is already running - shutting down in 10 seconds in order to start a repair..."
    echo "WARNING: databases will not be accessible until the repair process has finished (which could easily take an hour)"
    sleep 1 ; wait
    for n in {9..0} ; do
      printf $n ; sleep 1 ; wait ; printf \\b
    done
  fi

  mongod_stop
  
  echo "Repairing all mongo databases..."
  eval $REPAIRCMD
  RETVAL=$?

  mongod_running

  if [ "$IS_RUNNING" = "true" ]; then
    sleep 10
    mongod_stop
  fi

  mongod_start
  
}

mongod_status() {
  mongod_running
  if [ "$IS_RUNNING" = "true" ]; then
    echo "Mongod is running"
  else
    echo "Mongod is not running"
  fi
}

case "$1" in
  start)
    mongod_start
  ;;
  stop)
    mongod_stop
  ;;
  restart)
    mongod_stop
    mongod_start
  ;;
  repair)
    mongod_repair
  ;;
  status)
    mongod_status
  ;;
  *)
    echo "Usage: $0 {start|stop|restart|repair|status}"
    exit 1
  ;;
esac

exit $RETVAL