#!/bin/python
# Backups volumes of running containers
#
import subprocess, os, pathlib, pandas
from datetime import datetime


def bash(command):
    print(command)
    process = subprocess.Popen([command], stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
    out, err = process.communicate()
    stdout = out.splitlines()
    output = []
    for line in stdout:
        output.append(line.decode("utf-8"))
    if process.wait() > bool(0):
        print(command, out, err)
        raise Exception("Error is greater then 0")
    return output


def print_bash(command):
    output = bash(command)
    print(list_to_string(output))
    return output


def list_to_string(list):
    return str(' '.join(list))


print('start backup routine...')
print('start volume backups...')
backup_time = datetime.now().strftime("%Y%m%d%H%M%S")
backups_folder = '/Backups/'
dirname = os.path.dirname(__file__)
repository_name = os.path.basename(dirname)
print('load connection data...')
databases = pandas.read_csv(dirname + "/databases.csv", sep=";")
machine_id = bash("sha256sum /etc/machine-id")[0][0:64]
backup_repository_folder = backups_folder + machine_id + "/" + repository_name + "/"
volume_names = bash("docker volume ls --format '{{.Name}}'")
for volume_name in volume_names:
    print('start backup routine for volume: ' + volume_name)
    containers = bash("docker ps --filter volume=\""+ volume_name +"\" --format '{{.Names}}'")
    if len(containers) == 0:
        print('skipped due to no running containers using this volume.')
    else:
        container = containers[0]
        source_path = "/var/lib/docker/volumes/" + volume_name + "/_data"
        log_path = backup_repository_folder + "log.txt"
        destination_path = backup_repository_folder + "versions/"+ backup_time + "/" + volume_name
        versions_dir_path = backup_repository_folder + "versions/"
        databases_entries = databases.loc[databases['container'] == container]
        backup_versions = os.listdir(versions_dir_path)
        backup_versions.sort(reverse=True)
        last_version = backup_versions[0]
        last_version_dir_path = versions_dir_path + last_version + "/" + volume_name
        current_version_dir_path = versions_dir_path + backup_time + "/" + volume_name
        if len(databases_entries) == 1:
            print("Backup database...")
            sql_cp_source_path = destination_path + "/sql"
            sql_cp_destination_path = current_version_dir_path + "/sql"
            sql_destination_dir_file_path = sql_cp_destination_path + "/backup.sql"
            pathlib.Path(sql_cp_destination_path).mkdir(parents=True, exist_ok=True)
            database_entry = databases_entries.iloc[0]
            database_backup_command="docker exec "+ database_entry["container"] + " /usr/bin/mysqldump -u "+ database_entry["username"] + " -p"+ database_entry["password"] + " "+ database_entry["database"] + " > " + sql_destination_dir_file_path
            print_bash(database_backup_command)
        else:
            print("Backup files...")
            files_rsync_destination_path = destination_path + "/files"
            pathlib.Path(files_rsync_destination_path).mkdir(parents=True, exist_ok=True)
            print("Backup data during container is running...")
            rsync_command = "rsync -abP --delete --delete-excluded --log-file=" + log_path +" --backup-dir=" + files_version_dir_path +" '"+ source_path +"/' " + files_rsync_destination_path
            print_bash(rsync_command)
            print("stop containers...")
            print("Backup data after container is stopped...")
            print_bash("docker stop " + list_to_string(containers))
            print_bash(rsync_command)
            print("start containers...")
            print_bash("docker start " + list_to_string(containers))
    print("end backup routine for volume:" + volume_name)
print('finished volume backups.')
print('restart docker service...')
print_bash("systemctl restart docker")
print('finished backup routine.')