adding postgresql backup script

midgard/backup/mkpsqlbackup

@@ -0,0 +1,35 @@
+#!/bin/sh
+
+set -e
+
+# Default configuration
+DATABASES=''
+BACKUP_DIR=/data/backup/postgresql
+RETENTION_DAYS=7
+
+if ! source /etc/mkpsqlbackup.conf ; then
+	echo '[MKPSQLBACKUP] : Unable to load configuration file' >&2
+	exit 1
+fi
+
+if [ "$(id -un)" != 'postgres' ] ; then
+	echo '[MKPSQLBACKUP] : This script must be run as postgres user' >&2
+	exit 2
+fi
+
+FINAL_BACKUP_DIR="$BACKUP_DIR/-$(date '+%Y-%m-%d')"
+echo "[MKPSQLBACKUP] : Creating backup directory $FINAL_BACKUP_DIR"
+if ! mkdir -p "$FINAL_BACKUP_DIR" ; then
+	echo "[MKPSQLBACKUP] : Unable to create backup directory $FINAL_BACKUP_DIR"
+	exit 3
+fi
+
+for db in DATABASES ; do
+	echo "[MKPSQLBACKUP] : Backup of $db"
+	if ! pg_dump -Fc "$db" -f "$FINAL_BACKUP_DIR/$db" ; then
+		echo "[MKPSQLBACKUP] : Unable to backup database $db" >&2
+	fi
+done
+
+echo '[MKPSQLBACKUP] : Purging old backups'
+find "$BACKUP_DIR" -maxdepth 1 mindepth 1 -mtime +"$RETENTION_DAYS" -exec rm -rf '{}' ';'