Python. Automating creation backups of MySQL database.

import subprocess
import datetime
import sys
import os

def check_and_create_database(host, port, username, password, database):
    # Command to check if the database exists
    check_database_command = f"mysql -sN --host={host} --port={port} --user={username} --password={password} -e \"SELECT EXISTS(SELECT 1 FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = '{database}')\" 2>/dev/null"

    # Execute the command
    output = subprocess.check_output(check_database_command, shell=True)

    # If the output contains b'1', the database exists
    if b'1' in output:
        subprocess.run(check_database_command, shell=True, check=True)
        print(f"Database '{database}' already exists.")
        sys.exit(1)
    else:
        # If the command fails, the database does not exist
        print(f"Database '{database}' does not exist. Creating...")

        # Command to create the database
        create_database_command = f"mysql --host={host} --port={port} --user={username} --password={password} -e 'CREATE DATABASE {database}' 2>/dev/null"
        subprocess.run(create_database_command, shell=True)

def check_and_create_user(host, port, username, password, database, new_username, new_password):
    # Command to check if the user exists
    check_user_command = f"mysql -sN --host={host} --port={port} --user={username} --password={password} -e \"SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '{new_username}')\" 2>/dev/null"

    # Execute the command
    output = subprocess.check_output(check_user_command, shell=True)

    # If the output contains b'1', the user exists
    if b'1' in output:
        print(f"User '{new_username}' already exists.")
        sys.exit(1)
    else:
        # The user does not exist, create it
        print(f"User '{new_username}' does not exist. Creating...")

        # Command to create the user and grant privileges
        create_user_command = f"mysql --host={host} --port={port} --user={username} --password={password} -e \"CREATE USER '{new_username}'@'%' IDENTIFIED BY '{new_password}'; GRANT ALL PRIVILEGES ON {database}.* TO '{new_username}'@'%'; FLUSH PRIVILEGES;\" 2>/dev/null"
        subprocess.run(create_user_command, shell=True)

def backup_mysql_database(host, port, username, password, database, backup_path):

    # Check if the backup directory exists
    if not os.path.exists(backup_path):
        print(f"Error: Backup directory '{backup_path}' does not exist.")
        sys.exit(1)

    # Create a filename for the backup with the current date and time
    timestamp = datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
    backup_file = f"{backup_path}/{database}_{timestamp}.sql"

    # Command to create a database backup using mysqldump
    dump_command = f"mysqldump --no-tablespaces --host={host} --port={port} --user={username} --password={password} {database} > {backup_file} 2>/dev/null"

    # Execute the mysqldump command
    subprocess.run(dump_command, shell=True)

    return backup_file

def restore_mysql_database(host, port, username, password, database, backup_file):
    # Command to restore a database from a backup using mysql
    restore_command = f"mysql --host={host} --port={port} --user={username} --password={password} {database} < {backup_file} 2>/dev/null"

    # Execute the mysql command
    subprocess.run(restore_command, shell=True)

def main():
    # Connection parameters to the source MySQL database
    source_host = "127.0.0.1"
    source_port = "3309"
    source_username = "my_user"
    source_password = "my_password"
    source_database = "my_database"

    # Connection parameters to the target MySQL database
    target_host = "127.0.0.1"
    target_port = "3309"
    new_username = "new_username"
    new_password = "new_password"
    target_database = "my_database_two"

    target_username = "root"
    target_password = "root_password"

    # Path to save the backup locally
    backup_path = "my_dbs_dumps"

    # Check if source_database is different from target_database
    if source_database == target_database:
        print("Error: Source database should be different from target database.")
        sys.exit(1)

    # Check and create the target database if it does not exist
    check_and_create_database(target_host, target_port, target_username, target_password, target_database)

    # Check and create the target user if it does not exist
    check_and_create_user(target_host, target_port, target_username, target_password, target_database, new_username, new_password)

    # Create a backup of the MySQL database
    backup_file = backup_mysql_database(source_host, source_port, source_username, source_password, source_database, backup_path)
    print(f"Database backup created: {backup_file}")

    # Restore the database on the target server from the backup
    restore_mysql_database(target_host, target_port, target_username, target_password, target_database, backup_file)
    print("Database backup restored on the target server.")

if __name__ == "__main__":
    main()

dmi@dmi-laptop:~/my_python$ python3 mysql_backup_restore.py 
Database 'my_database_two' does not exist. Creating...
User 'new_username' does not exist. Creating...
Database backup created: my_dbs_dumps/my_database_2024-05-13_20-05-24.sql
Database backup restored on the target server.
dmi@dmi-laptop:~/my_python$