api/app/backup.py

import os, subprocess, logging
from rest_framework.decorators import api_view
from rest_framework.response import Response
from app.models import *
from django.db import close_old_connections
from datetime import datetime, timedelta

BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
static_folder = os.path.join(BASE_DIR, "static")

#==========================================================================================
def backup_postgres(db_name, db_user, db_host, db_port):
    # close old connections
    close_old_connections()

    # Configure logging
    logging.basicConfig(
        level=logging.INFO,
        format='%(asctime)s - %(levelname)s - %(message)s',
        filename="{}/{}/backup_postgres.log".format(static_folder, 'log')
    )
    output_dir = "{}/database".format(static_folder)

    """
    Backup a PostgreSQL database using pg_dump.
    
    Args:
        db_name (str): Name of the database to backup
        db_user (str): Database user
        db_host (str): Database host
        db_port (str): Database port
        output_dir (str): Directory to store the backup file
    """
    try:
        # Create output directory if it doesn't exist
        os.makedirs(output_dir, exist_ok=True)
        
        # Generate timestamp for backup file
        timestamp = datetime.now().strftime('%Y%m%d_%H%M%S')
        backup_file = os.path.join(output_dir, f'{db_name}_backup_{timestamp}.sql')
        start_time = datetime.now()
        
        # Construct pg_dump command
        pg_dump_cmd = [
            'pg_dump',
            '-U', db_user,
            '-h', db_host,
            '-p', db_port,
            '-F', 'p',  # Plain SQL format
            '-b',       # Include large objects
            '-v',       # Verbose output
            db_name
        ]
        
        # Set PGPASSWORD environment variable to avoid password prompt
        os.environ['PGPASSWORD'] = "V59yNLN42a9Q7xT" #input("Enter database password: ")
        
        # Execute pg_dump and save output to file
        logging.info(f"Starting backup of database {db_name} to {backup_file}")
        with open(backup_file, 'w') as f:
            process = subprocess.run(
                pg_dump_cmd,
                stdout=f,
                stderr=subprocess.PIPE,
                universal_newlines=True,
                check=True
            )
        
        logging.info(f"Backup completed successfully: {backup_file}")
        print(f"Backup saved to {backup_file}")
        backup = Backup(code="DB{}".format(datetime.now().strftime('%Y%m%d%H%M')), name="database-backup", 
                status=Task_Status.objects.get(pk=4), start_time=start_time, end_time=datetime.now(), file=f'{db_name}_backup_{timestamp}.sql')
        backup.save()
        return {"status": "success"}
        
    except subprocess.CalledProcessError as e:
        logging.error(f"Backup failed: {e.stderr}")
        print(f"Error during backup: {e.stderr}")
        backup = Backup(code="DB{}".format(datetime.now().strftime('%Y%m%d%H%M')), name="database-backup", 
            status=Task_Status.objects.get(pk=3), start_time=start_time, end_time=datetime.now())
        backup.save()
        return {"status": "error", "text": str(e.stderr)}
    except Exception as e:
        logging.error(f"Unexpected error: {str(e)}")
        print(f"Unexpected error: {str(e)}")
        backup = Backup(code="DB{}".format(datetime.now().strftime('%Y%m%d%H%M')), name="database-backup", 
            status=Task_Status.objects.get(pk=3), start_time=start_time, end_time=datetime.now())
        backup.save()
        return {"status": "error", "text": str(e)}

#==========================================================================================
def restore_postgres(db_name, db_user, db_host, db_port, backup_file):
    """
    Restore a PostgreSQL database from a .sql backup file using psql.
    
    Args:
        db_name (str): Name of the database to restore
        db_user (str): Database user
        db_host (str): Database host
        db_port (str): Database port
        backup_file (str): Path to the backup .sql file
    """
    # Configure logging
    logging.basicConfig(
        level=logging.INFO,
        format='%(asctime)s - %(levelname)s - %(message)s',
        filename="{}/{}/backup_postgres.log".format(static_folder, 'log')
    )
    try:
        # Verify backup file exists
        if not os.path.exists(backup_file):
            raise FileNotFoundError(f"Backup file not found: {backup_file}")

        # Construct psql command
        psql_cmd = [
            'psql',
            '-U', db_user,
            '-h', db_host,
            '-p', db_port,
            '-d', db_name,
            '-f', backup_file
        ]
        
        # Set PGPASSWORD environment variable to avoid password prompt
        os.environ['PGPASSWORD'] = "V59yNLN42a9Q7xT" #input("Enter database password: ")
        
        # Execute psql to restore the database
        logging.info(f"Starting restore of database {db_name} from {backup_file}")
        process = subprocess.run(
            psql_cmd,
            stderr=subprocess.PIPE,
            universal_newlines=True,
            check=True
        )
        
        logging.info(f"Restore completed successfully for database {db_name}")
        print(f"Database {db_name} restored successfully from {backup_file}")
        
    except subprocess.CalledProcessError as e:
        logging.error(f"Restore failed: {e.stderr}")
        print(f"Error during restore: {e.stderr}")
    except FileNotFoundError as e:
        logging.error(str(e))
        print(str(e))
    except Exception as e:
        logging.error(f"Unexpected error: {str(e)}")
        print(f"Unexpected error: {str(e)}")
    finally:
        # Clean up environment variable
        os.environ.pop('PGPASSWORD', None)

#==========================================================================================
def delete_old_dbbackup():
    # close old connections
    close_old_connections()
    # start
    begin_date = (datetime.now() - timedelta(days=7)).date()
    rows = Backup.objects.filter(name='database-backup', create_time__date__lte=begin_date, status=4)
    for row in rows:
        file_path = "{}/database/{}".format(static_folder, row.file)
        try:
            os.remove(file_path)
            print("Đã xóa file:", file_path)
            row.note = 'file was deleted'
            row.save()

        except FileNotFoundError:
            print("File không tồn tại:", file_path)
        except PermissionError:
            print("Không có quyền xóa file:", file_path)
        except Exception as e:
            print("Lỗi khác:", e)

#==========================================================================================
@api_view(['GET', 'POST'])
def backup_database(request):       
    if request.method == 'GET':
        result = backup_postgres("y99", "postgres", "107.155.65.79", "5423")
    else:
        result = backup_postgres(request.data["db_name"], request.data["db_user"], request.data["db_host"], request.data["db_port"])
    return Response(result)