A hopefully working backup script for mongo. Use by providing names of dbs to backup, check if MONGODUMP_DEST exist prior to executing.

backup-anymongo.sh

#!/bin/bash
 
for var in "$@"
do
  #Force file syncronization and lock writes
  mongo admin --eval "printjson(db.fsyncLock())"
   
  #Keep the trailing slash
  MONGODUMP_DEST="/home/ubuntu/mongobackups/"
  MONGO_DATABASE="$var"

  MONGODUMP_PATH="/usr/bin/mongodump"
  MONGO_HOST="localhost" #replace with your server ip
  MONGO_PORT="27017"
   
  TIMESTAMP=`date +%F-%H%M`
   
  # Create backup
  $MONGODUMP_PATH -h $MONGO_HOST:$MONGO_PORT -d $MONGO_DATABASE -o $MONGODUMP_DEST 
   
  # Add timestamp to backup
  cd $MONGODUMP_DEST
  mv $MONGO_DATABASE mongodb-$HOSTNAME-$TIMESTAMP
  tar cf mongodb-$MONGO_DATABASE-$TIMESTAMP.tar mongodb-$HOSTNAME-$TIMESTAMP
  rm -rf mongodb-$HOSTNAME-$TIMESTAMP
   
   
  #Unlock database writes
  mongo admin --eval "printjson(db.fsyncUnlock())"
done