PostgreSql Daily Backup & Restore

postgres_backup.sh

#!/bin/bash
#
# PostgreSQL Daily Backup Script
# This script creates daily backups of PostgreSQL databases with rotation
#

# Configuration variables
BACKUP_DIR="/var/backups/postgresql"
DB_USER="postgres"
DB_PASSWORD=""  # For security, consider using a .pgpass file instead
DB_HOST="localhost"
DB_PORT="5432"
DAYS_TO_KEEP=7
DATE_FORMAT=$(date +"%Y-%m-%d")
LOG_FILE="${BACKUP_DIR}/backup_log_${DATE_FORMAT}.log"

# Create backup directory if it doesn't exist
mkdir -p "$BACKUP_DIR"

# Initialize log file
echo "===== PostgreSQL Backup Started at $(date) =====" > "$LOG_FILE"

# Function to log messages
log_message() {
    echo "$(date +"%Y-%m-%d %H:%M:%S") - $1" >> "$LOG_FILE"
    echo "$1"
}

# Function to handle errors
handle_error() {
    log_message "ERROR: $1"
    exit 1
}

# Check if pg_dump is available
if ! command -v pg_dump &> /dev/null; then
    handle_error "pg_dump command not found. Please install PostgreSQL client tools."
fi

# Backup all databases
backup_all_databases() {
    log_message "Starting backup of all databases..."
    
    # Get list of databases, excluding template databases
    DB_LIST=$(PGPASSWORD="$DB_PASSWORD" psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -t -c "SELECT datname FROM pg_database WHERE datname NOT IN ('template0', 'template1') AND datname NOT LIKE 'pg_%';" 2>> "$LOG_FILE")
    
    if [ $? -ne 0 ]; then
        handle_error "Failed to get database list"
    fi
    
    # Backup each database
    for DB_NAME in $DB_LIST; do
        backup_single_database "$DB_NAME"
    done
    
    log_message "All database backups completed!"
}

# Backup a single database
backup_single_database() {
    DB_NAME="$1"
    BACKUP_FILE="${BACKUP_DIR}/${DB_NAME}_${DATE_FORMAT}.sql.gz"
    
    log_message "Backing up database: $DB_NAME to $BACKUP_FILE"
    
    PGPASSWORD="$DB_PASSWORD" pg_dump -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" \
        -F p -b -v -f - "$DB_NAME" 2>> "$LOG_FILE" | gzip > "$BACKUP_FILE"
    
    if [ $? -ne 0 ]; then
        log_message "Warning: There might have been a problem with the backup of $DB_NAME. Check the log for details."
    else
        log_message "Successfully backed up database: $DB_NAME"
        # Set appropriate permissions for backup file
        chmod 600 "$BACKUP_FILE"
    fi
}

# Delete old backups
rotate_backups() {
    log_message "Removing backups older than $DAYS_TO_KEEP days..."
    find "$BACKUP_DIR" -name "*.sql.gz" -type f -mtime +$DAYS_TO_KEEP -delete
    find "$BACKUP_DIR" -name "backup_log_*.log" -type f -mtime +$DAYS_TO_KEEP -delete
    log_message "Old backups removed!"
}

# Main execution
log_message "Starting PostgreSQL backup process..."

# Execute backups
backup_all_databases

# Rotate old backups
rotate_backups

log_message "Backup process completed successfully!"
echo "===== PostgreSQL Backup Completed at $(date) =====" >> "$LOG_FILE"

exit 0

postgres_restore.sh

#!/bin/bash
#
# PostgreSQL Backup Restore Script
# This script restores PostgreSQL databases from backups created by the backup script
#

# Configuration variables
BACKUP_DIR="/var/backups/postgresql"
DB_USER="postgres"
DB_PASSWORD=""  # For security, consider using a .pgpass file instead
DB_HOST="localhost"
DB_PORT="5432"
LOG_FILE="${BACKUP_DIR}/restore_log_$(date +"%Y-%m-%d_%H-%M-%S").log"

# Create log directory if it doesn't exist
mkdir -p "$BACKUP_DIR"

# Initialize log file
echo "===== PostgreSQL Restore Started at $(date) =====" > "$LOG_FILE"

# Function to log messages
log_message() {
    echo "$(date +"%Y-%m-%d %H:%M:%S") - $1" >> "$LOG_FILE"
    echo "$1"
}

# Function to handle errors
handle_error() {
    log_message "ERROR: $1"
    exit 1
}

# Check if psql is available
if ! command -v psql &> /dev/null; then
    handle_error "psql command not found. Please install PostgreSQL client tools."
fi

# Display available backups
list_backups() {
    echo "Available database backups:"
    ls -lt "$BACKUP_DIR" | grep ".sql.gz" | awk '{print NR". "$9}'
}

# Restore a database from backup
restore_database() {
    BACKUP_FILE="$1"
    DB_NAME="$2"
    
    # Check if backup file exists
    if [ ! -f "$BACKUP_FILE" ]; then
        handle_error "Backup file does not exist: $BACKUP_FILE"
    fi
    
    # Check if database exists
    DB_EXISTS=$(PGPASSWORD="$DB_PASSWORD" psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -t -c "SELECT 1 FROM pg_database WHERE datname='$DB_NAME';" 2>> "$LOG_FILE")
    
    if [ "$DB_EXISTS" = " 1" ]; then
        read -p "Database $DB_NAME already exists. Do you want to drop and recreate it? (y/n): " CONFIRM
        if [[ "$CONFIRM" =~ ^[Yy]$ ]]; then
            log_message "Dropping existing database: $DB_NAME"
            PGPASSWORD="$DB_PASSWORD" psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -c "DROP DATABASE \"$DB_NAME\";" 2>> "$LOG_FILE"
            if [ $? -ne 0 ]; then
                handle_error "Failed to drop database $DB_NAME"
            fi
        else
            log_message "Restore cancelled by user."
            exit 0
        fi
    fi
    
    # Create database
    log_message "Creating database: $DB_NAME"
    PGPASSWORD="$DB_PASSWORD" psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -c "CREATE DATABASE \"$DB_NAME\";" 2>> "$LOG_FILE"
    if [ $? -ne 0 ]; then
        handle_error "Failed to create database $DB_NAME"
    fi
    
    # Restore from backup
    log_message "Restoring $DB_NAME from $BACKUP_FILE..."
    gunzip -c "$BACKUP_FILE" | PGPASSWORD="$DB_PASSWORD" psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -d "$DB_NAME" 2>> "$LOG_FILE"
    
    if [ $? -ne 0 ]; then
        log_message "Warning: There might have been a problem with the restore of $DB_NAME. Check the log for details."
    else
        log_message "Successfully restored database: $DB_NAME from $BACKUP_FILE"
    fi
}

# Interactive mode - let user choose which backup to restore
interactive_restore() {
    # List available backups
    list_backups
    
    # Ask user to select a backup
    read -p "Enter the number of the backup to restore: " BACKUP_NUM
    
    # Get the selected backup file
    BACKUP_FILE=$(ls -t "$BACKUP_DIR"/*.sql.gz | sed -n "${BACKUP_NUM}p")
    
    if [ -z "$BACKUP_FILE" ]; then
        handle_error "Invalid backup number"
    fi
    
    # Extract database name from backup file
    DB_NAME=$(basename "$BACKUP_FILE" | sed 's/\(.*\)_[0-9]\{4\}-[0-9]\{2\}-[0-9]\{2\}\.sql\.gz/\1/')
    
    echo "Selected backup file: $BACKUP_FILE"
    echo "Database name: $DB_NAME"
    
    # Confirm restoration
    read -p "Do you want to restore this database? (y/n): " CONFIRM
    if [[ "$CONFIRM" =~ ^[Yy]$ ]]; then
        restore_database "$BACKUP_FILE" "$DB_NAME"
    else
        log_message "Restore cancelled by user."
    fi
}

# Specific restore - restore a specific backup file for a specific database
specific_restore() {
    if [ -z "$1" ] || [ -z "$2" ]; then
        echo "Usage: $0 -s <backup_file> <database_name>"
        exit 1
    fi
    
    BACKUP_FILE="$1"
    DB_NAME="$2"
    
    # Check if backup file exists
    if [ ! -f "$BACKUP_FILE" ]; then
        # Try adding the backup directory
        BACKUP_FILE="$BACKUP_DIR/$BACKUP_FILE"
        if [ ! -f "$BACKUP_FILE" ]; then
            handle_error "Backup file does not exist: $1"
        fi
    fi
    
    restore_database "$BACKUP_FILE" "$DB_NAME"
}

# Latest restore - restore the latest backup of a database
latest_restore() {
    if [ -z "$1" ]; then
        echo "Usage: $0 -l <database_name>"
        exit 1
    fi
    
    DB_NAME="$1"
    LATEST_BACKUP=$(ls -t "$BACKUP_DIR"/${DB_NAME}_*.sql.gz 2>/dev/null | head -n1)
    
    if [ -z "$LATEST_BACKUP" ]; then
        handle_error "No backup found for database $DB_NAME"
    fi
    
    echo "Latest backup found: $LATEST_BACKUP"
    read -p "Do you want to restore this database? (y/n): " CONFIRM
    if [[ "$CONFIRM" =~ ^[Yy]$ ]]; then
        restore_database "$LATEST_BACKUP" "$DB_NAME"
    else
        log_message "Restore cancelled by user."
    fi
}

# Main execution
case "$1" in
    -i|--interactive)
        interactive_restore
        ;;
    -s|--specific)
        specific_restore "$2" "$3"
        ;;
    -l|--latest)
        latest_restore "$2"
        ;;
    *)
        echo "PostgreSQL Backup Restore Script"
        echo "Usage:"
        echo "  $0 -i, --interactive    : Interactive mode, select backup from a list"
        echo "  $0 -s, --specific <file> <db> : Restore specific backup file to database"
        echo "  $0 -l, --latest <db>    : Restore the latest backup of a database"
        exit 1
        ;;
esac

log_message "Restore process completed!"
echo "===== PostgreSQL Restore Completed at $(date) =====" >> "$LOG_FILE"

exit 0