#!/bin/bash
#######################################################################
# PG_BACKUP.SHL
#
# Created       : Martin Foster
# Modified      : 24-Nov-2004
#######################################################################
#
# Due to limitations with the PostgreSQL database backup tool not
# accepting passwords on the command prompt to automate the process and
# thus requiring a loose set of security.   This script instead calls
# the backup proceedure locally on the server and through SSH/RSH sends
# the results back over the network to the appropriate workstation.
#
# Advantages to this system when making use of SSH is the encryption
# and certificate based authentication allowing for security while
# ease of use.   This also runs the backup on the database server
# allowing for a copy to be generated simultaneously if so desired.

#################
# Data Members

#
# Site specific configuration
BACKUP='/var/archives/postgres'				# Backup path
DB='ethereal'						# Databases to backup
CREDENTIALS='martin@io'					# Username/host combination

#
# Date based hiearchy
DAY=`date +%d`
MONTH=`date +%m`
YEAR=`date +%y`

#
# Location of utilities
ARCHIVER="/usr/bin/bzip2"				# Archive to compress stream
DUMP="/usr/local/bin/pg_dump -cDU postgres"		# Database dumping utility
FILTER="/usr/bin/grep -v 'INSERT INTO param'"		# Filter used with dump
REMOTE="/usr/bin/ssh"					# Remote access capability

#
# File settings
PERM='0644'						# Permissions to take on
OWNER='root'						# Owner of file
GROUP='wheel'						# Owner group
EXT='.bz2'						# Extension to use

#
# Verbosity
VERBOSE='NO'						# Display information to screen


#################
# Program area

  # Explain what happens
  if [ "$VERBOSE" = "YES" ]
   then
	# Go change into the log dir
	if [ -d $BACKUP ]
 	 then
		# see if month dir exists in log dir - if not create one
		if [ ! -d "$BACKUP/$YEAR$MONTH" ]
		 then
			# date dir does not exist in the log dir - create one
			/bin/mkdir "$BACKUP/$YEAR$MONTH" 2>&1 >/dev/null

			if [ $? -ne 0 ]
			 then
			 	# could not create log date dir
				echo -e "  Could not create: $BACKUP/$YEAR$MONTH - exiting!\n"
				exit 1
	 		 else
				# created dir
				echo -e "  Created: $BACKUP/$YEAR$MONTH\n"
			fi
		 fi

		# Change working directory
		cd "$BACKUP/$YEAR$MONTH"


		# Cycle through list
		for SINGLE in $DB
		 do
			echo -e "  Initiating backup of database: $SINGLE"
			$REMOTE $CREDENTIALS "$DUMP $SINGLE | $FILTER | $ARCHIVER" > $SINGLE-$MONTH$DAY$EXT
			
			echo -e "    Setting permissions..."
			chmod $PERM $SINGLE-$MONTH$DAY$EXT

			echo -e "    Setting permissions..."
			chown $OWNER $SINGLE-$MONTH$DAY$EXT

			echo -e "    Setting permissions..."
			chgrp $GROUP $SINGLE-$MONTH$DAY$EXT

			# Verify file exists
			if [ -f "$SINGLE-$MONTH$DAY.bz2" ]
			 then
				echo -e "  Backup succesful!"
			 else
				echo -e "  Backup failed!"
			fi
		 done		

	 else
		# Warning
		echo -e "  Working directory not found: $BACKUP\n"
	fi

    # Lack of detail
    else
	# Go change into the log dir
	if [ -d $BACKUP ]
 	 then
		# see if month dir exists in log dir - if not create one
		if [ ! -d "$BACKUP/$YEAR$MONTH" ]
		 then
			# date dir does not exist in the log dir - create one
			/bin/mkdir "$BACKUP/$YEAR$MONTH" 2>&1 >/dev/null

			if [ $? -ne 0 ]
			 then
			 	# could not create log date dir
				echo -e "Could not create: $BACKUP/$YEAR$MONTH - exiting!\n"
				exit 1
			fi
		 fi

		# Change working directory
		cd "$BACKUP/$YEAR$MONTH"

		# Cycle through list
		for SINGLE in $DB
		 do
			$REMOTE $CREDENTIALS "$DUMP $SINGLE | $FILTER | $ARCHIVER" > $SINGLE-$MONTH$DAY$EXT
			
			chmod $PERM $SINGLE-$MONTH$DAY$EXT
			chown $OWNER $SINGLE-$MONTH$DAY$EXT
			chgrp $GROUP $SINGLE-$MONTH$DAY$EXT

			# Verify file exists
			if [ ! -f "$SINGLE-$MONTH$DAY$EXT" ]
			 then
				echo -e "  Backup of $SINGLE failed!"
			fi
		 done		

	 else
		# Warning
		echo -e "  Working directory not found: $BACKUP\n"
	fi
   fi