Automated Backup on Linux

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Revision as of 09:28, 28 June 2012 by Kesslernetworks (Talk | contribs)

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Here are some scripts which will backup all databases in a cluster individually, optionally only backing up the schema for a set list. The reason one might wish to use this over pg_dumpall is that you may only wish to restore individual databases from a backup, whereas pg_dumpall dumps a plain SQL copy into a single file. This also provides the option of specifying which databases you only want the schema of. The idea is to run these in a nightly cron job.

  • pg_backup.config - The main configuration file. This should be the only file which needs user modifications.
  • pg_backup.sh - The normal backup script which will go through each database and save a gzipped and/or a custom format copy of the backup into a date-based directory.
  • pg_backup_rotated.sh - The same as above except it will delete expired backups based on the configuration.

pg_backup.config

##############################
## POSTGRESQL BACKUP CONFIG ##
##############################
 
# Optional system user to run backups as.  If the user the script is running as doesn't match this
# the script terminates.  Leave blank to skip check.
BACKUP_USER=
 
# Optional hostname to adhere to pg_hba policies.  Will default to "localhost" if none specified.
HOSTNAME=
 
# Optional username to connect to database as.  Will default to "postgres" if none specified.
USERNAME=
 
# This dir will be created if it doesn't exist.  This must be writable by the user the script is
# running as.
BACKUP_DIR=/home/backups/database/postgresql/
 
# List of strings to match against in database name, separated by space or comma, for which we only
# wish to keep a backup of the schema, not the data. Any database names which contain any of these
# values will be considered candidates. (e.g. "system_log" will match "dev_system_log_2010-01")
SCHEMA_ONLY_LIST=""
 
# Will produce a custom-format backup if set to "yes"
ENABLE_CUSTOM_BACKUPS=yes
 
# Will produce a gzipped plain-format backup if set to "yes"
ENABLE_PLAIN_BACKUPS=yes
 
 
#### SETTINGS FOR ROTATED BACKUPS ####
 
# Which day to take the weekly backup from (1-7 = Monday-Sunday)
DAY_OF_WEEK_TO_KEEP=5
 
# Number of days to keep daily backups
DAYS_TO_KEEP=7
 
# How many weeks to keep weekly backups
WEEKS_TO_KEEP=5
 
######################################

pg_backup.sh

#!/bin/bash
 
###########################
####### LOAD CONFIG #######
###########################
 
while [ $# -gt 0 ]; do
        case $1 in
                -c)
                        if [ -r "$2" ]; then
                                source "$2"
                                shift 2
                        else
                                ${ECHO} "Ureadable config file \"$2\""
                                exit 1
                        fi
                        ;;
                *)
                        ${ECHO} "Unknown Option \"$1\""
                        exit 2
                        ;;
        esac
done
 
if [ $# = 0 ]; then
        SCRIPTPATH=$(cd ${0%/*} && pwd -P)
        source $SCRIPTPATH/pg_backup.config
fi;
 
###########################
#### PRE-BACKUP CHECKS ####
###########################
 
# Make sure we're running as the required backup user
if [ "$BACKUP_USER" != "" -a "$(id -un)" != "$BACKUP_USER" ]; then
	echo "This script must be run as $BACKUP_USER. Exiting."
	exit 1;
fi;
 
 
###########################
### INITIALISE DEFAULTS ###
###########################
 
if [ ! $HOSTNAME ]; then
	HOSTNAME="localhost"
fi;
 
if [ ! $USERNAME ]; then
	USERNAME="postgres"
fi;
 
 
###########################
#### START THE BACKUPS ####
###########################
 
 
FINAL_BACKUP_DIR=$BACKUP_DIR"`date +\%Y-\%m-\%d`/"
 
echo "Making backup directory in $FINAL_BACKUP_DIR"
 
if ! mkdir -p $FINAL_BACKUP_DIR; then
	echo "Cannot create backup directory in $FINAL_BACKUP_DIR. Go and fix it!"
	exit 1;
fi;
 
 
###########################
### SCHEMA-ONLY BACKUPS ###
###########################
 
for SCHEMA_ONLY_DB in ${SCHEMA_ONLY_LIST//,/ }
do
	SCHEMA_ONLY_CLAUSE="$SCHEMA_ONLY_CLAUSE or datname ~ '$SCHEMA_ONLY_DB'"
done
 
SCHEMA_ONLY_QUERY="select datname from pg_database where false $SCHEMA_ONLY_CLAUSE order by datname;"
 
echo -e "\n\nPerforming schema-only backups"
echo -e "--------------------------------------------\n"
 
SCHEMA_ONLY_DB_LIST=`psql -h "$HOSTNAME" -U "$USERNAME" -At -c "$SCHEMA_ONLY_QUERY" postgres`
 
echo -e "The following databases were matched for schema-only backup:\n${SCHEMA_ONLY_DB_LIST}\n"
 
for DATABASE in $SCHEMA_ONLY_DB_LIST
do
	echo "Schema-only backup of $DATABASE"
 
	if ! pg_dump -Fp -s -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" | gzip > $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz.in_progress; then
		echo "[!!ERROR!!] Failed to backup database schema of $DATABASE"
	else
		mv $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz
	fi
done
 
 
###########################
###### FULL BACKUPS #######
###########################
 
for SCHEMA_ONLY_DB in ${SCHEMA_ONLY_LIST//,/ }
do
	EXCLUDE_SCHEMA_ONLY_CLAUSE="$EXCLUDE_SCHEMA_ONLY_CLAUSE and datname !~ '$SCHEMA_ONLY_DB'"
done
 
FULL_BACKUP_QUERY="select datname from pg_database where not datistemplate and datallowconn $EXCLUDE_SCHEMA_ONLY_CLAUSE order by datname;"
 
echo -e "\n\nPerforming full backups"
echo -e "--------------------------------------------\n"
 
for DATABASE in `psql -h "$HOSTNAME" -U "$USERNAME" -At -c "$FULL_BACKUP_QUERY" postgres`
do
	if [ $ENABLE_PLAIN_BACKUPS = "yes" ]
	then
		echo "Plain backup of $DATABASE"
 
		if ! pg_dump -Fp -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" | gzip > $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress; then
			echo "[!!ERROR!!] Failed to produce plain backup database $DATABASE"
		else
			mv $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE".sql.gz
		fi
	fi
 
	if [ $ENABLE_CUSTOM_BACKUPS = "yes" ]
	then
		echo "Custom backup of $DATABASE"
 
		if ! pg_dump -Fc -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" -f $FINAL_BACKUP_DIR"$DATABASE".custom.in_progress; then
			echo "[!!ERROR!!] Failed to produce custom backup database $DATABASE"
		else
			mv $FINAL_BACKUP_DIR"$DATABASE".custom.in_progress $FINAL_BACKUP_DIR"$DATABASE".custom
		fi
	fi
 
done
 
echo -e "\nAll database backups complete!"

pg_backup_rotated.sh

#!/bin/bash
 
###########################
####### LOAD CONFIG #######
###########################
 
SCRIPTPATH=$(cd ${0%/*} && pwd -P)
source $SCRIPTPATH/pg_backup.config
 
 
###########################
#### PRE-BACKUP CHECKS ####
###########################
 
# Make sure we're running as the required backup user
if [ $BACKUP_USER != "" -a "$(id -un)" != "$BACKUP_USER" ]; then
	echo "This script must be run as $BACKUP_USER. Exiting."
	exit 1;
fi;
 
 
###########################
### INITIALISE DEFAULTS ###
###########################
 
if [ ! $HOSTNAME ]; then
	HOSTNAME="localhost"
fi;
 
if [ ! $USERNAME ]; then
	USERNAME="postgres"
fi;
 
 
###########################
#### START THE BACKUPS ####
###########################
 
function perform_backups()
{
	SUFFIX=$1
	FINAL_BACKUP_DIR=$BACKUP_DIR"`date +\%Y-\%m-\%d`$SUFFIX/"
 
	echo "Making backup directory in $FINAL_BACKUP_DIR"
 
	if ! mkdir -p $FINAL_BACKUP_DIR; then
		echo "Cannot create backup directory in $FINAL_BACKUP_DIR. Go and fix it!"
		exit 1;
	fi;
 
 
	###########################
	### SCHEMA-ONLY BACKUPS ###
	###########################
 
	for SCHEMA_ONLY_DB in ${SCHEMA_ONLY_LIST//,/ }
	do
	        SCHEMA_ONLY_CLAUSE="$SCHEMA_ONLY_CLAUSE or datname ~ '$SCHEMA_ONLY_DB'"
	done
 
	SCHEMA_ONLY_QUERY="select datname from pg_database where false $SCHEMA_ONLY_CLAUSE order by datname;"
 
	echo -e "\n\nPerforming schema-only backups"
	echo -e "--------------------------------------------\n"
 
	SCHEMA_ONLY_DB_LIST=`psql -h "$HOSTNAME" -U "$USERNAME" -At -c "$SCHEMA_ONLY_QUERY" postgres`
 
	echo -e "The following databases were matched for schema-only backup:\n${SCHEMA_ONLY_DB_LIST}\n"
 
	for DATABASE in $SCHEMA_ONLY_DB_LIST
	do
	        echo "Schema-only backup of $DATABASE"
 
	        if ! pg_dump -Fp -s -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" | gzip > $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz.in_progress; then
	                echo "[!!ERROR!!] Failed to backup database schema of $DATABASE"
	        else
	                mv $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz
	        fi
	done
 
 
	###########################
	###### FULL BACKUPS #######
	###########################
 
	for SCHEMA_ONLY_DB in ${SCHEMA_ONLY_LIST//,/ }
	do
		EXCLUDE_SCHEMA_ONLY_CLAUSE="$EXCLUDE_SCHEMA_ONLY_CLAUSE and datname !~ '$SCHEMA_ONLY_DB'"
	done
 
	FULL_BACKUP_QUERY="select datname from pg_database where not datistemplate and datallowconn $EXCLUDE_SCHEMA_ONLY_CLAUSE order by datname;"
 
	echo -e "\n\nPerforming full backups"
	echo -e "--------------------------------------------\n"
 
	for DATABASE in `psql -h "$HOSTNAME" -U "$USERNAME" -At -c "$FULL_BACKUP_QUERY" postgres`
	do
		if [ $ENABLE_PLAIN_BACKUPS = "yes" ]
		then
			echo "Plain backup of $DATABASE"
 
			if ! pg_dump -Fp -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" | gzip > $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress; then
				echo "[!!ERROR!!] Failed to produce plain backup database $DATABASE"
			else
				mv $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE".sql.gz
			fi
		fi
 
		if [ $ENABLE_CUSTOM_BACKUPS = "yes" ]
		then
			echo "Custom backup of $DATABASE"
 
			if ! pg_dump -Fc -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" -f $FINAL_BACKUP_DIR"$DATABASE".custom.in_progress; then
				echo "[!!ERROR!!] Failed to produce custom backup database $DATABASE"
			else
				mv $FINAL_BACKUP_DIR"$DATABASE".custom.in_progress $FINAL_BACKUP_DIR"$DATABASE".custom
			fi
		fi
 
	done
 
	echo -e "\nAll database backups complete!"
}
 
# MONTHLY BACKUPS
 
DAY_OF_MONTH=`date +%d`
 
if [ $DAY_OF_MONTH = "1" ];
then
	# Delete all expired monthly directories
	find $BACKUP_DIR -maxdepth 1 -name "*-monthly" -exec rm -rf '{}' ';'
 
	perform_backups "-monthly"
 
	exit 0;
fi
 
# WEEKLY BACKUPS
 
DAY_OF_WEEK=`date +%u` #1-7 (Monday-Sunday)
EXPIRED_DAYS=`expr $((($WEEKS_TO_KEEP * 7) + 1))`
 
if [ $DAY_OF_WEEK = $DAY_OF_WEEK_TO_KEEP ];
then
	# Delete all expired weekly directories
	find $BACKUP_DIR -maxdepth 1 -mtime +$EXPIRED_DAYS -name "*-weekly" -exec rm -rf '{}' ';'
 
	perform_backups "-weekly"
 
	exit 0;
fi
 
# DAILY BACKUPS
 
# Delete daily backups 7 days old or more
find $BACKUP_DIR -maxdepth 1 -mtime +$DAYS_TO_KEEP -name "*-daily" -exec rm -rf '{}' ';'
 
perform_backups "-daily"
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