building_manager.py

#!/usr/bin/env python3
""" Python module to assist creating and maintaining docker openHab stacks."""
import crypt
from enum import Enum
import logging
import os
import sys
from hashlib import md5
from shutil import copy2
from subprocess import PIPE, run

import bcrypt
import docker
import questionary as qust
from ruamel.yaml import YAML
from prompt_toolkit.styles import Style

# Configure YAML
yaml = YAML()
yaml.indent(mapping=4, sequence=4, offset=2)

# Log level during development is info
logging.basicConfig(level=logging.WARNING)

# Prompt style
st = Style([
    ('qmark', 'fg:#00c4b4 bold'),     # token in front of question
    ('question', 'bold'),             # question text
    ('answer', 'fg:#00c4b4 bold'),    # submitted answer question
    ('pointer', 'fg:#00c4b4 bold'),   # pointer for select and checkbox
    ('selected', 'fg:#00c4b4'),       # selected item checkbox
    ('separator', 'fg:#00c4b4'),      # separator in lists
    ('instruction', '')               # user instructions for selections
])

# ******************************
# Constants <<<
# ******************************

# Directories for config generation
CUSTOM_DIR = 'custom_configs'
TEMPLATE_DIR = 'template_configs'
COMPOSE_NAME = 'docker-stack.yml'
SKELETON_NAME = 'docker-skeleton.yml'
TEMPLATES_NAME = 'docker-templates.yml'
CONFIG_DIRS = ['mosquitto', 'nodered', 'ssh',
               'traefik', 'volumerize', 'postgres', 'pb-framr']
TEMPLATE_FILES = [
    'mosquitto/mosquitto.conf', 'nodered/nodered_package.json',
    'pb-framr/logo.svg', 'nodered/nodered_settings.js',
    'ssh/sshd_config', 'traefik/traefik.toml'
]
EDIT_FILES = {
    "mosquitto_passwords": "mosquitto/mosquitto_passwords",
    "sftp_users": "ssh/sftp_users.conf",
    "traefik_users": "traefik/traefik_users",
    "id_rsa": "ssh/id_rsa",
    "host_key": "ssh/ssh_host_ed25519_key",
    "known_hosts": "ssh/known_hosts",
    "backup_config": "volumerize/backup_config.json",
    "postgres_user": "postgres/user",
    "postgres_passwd": "postgres/passwd",
    "pb_framr_pages": "pb-framr/pages.json"
}
CONSTRAINTS = {"building": "node.labels.building"}

# Default Swarm port
SWARM_PORT = 2377
# UID for admin
UID = 9001
# Username for admin
ADMIN_USER = 'ohadmin'


class Service(Enum):
    SFTP = ("SFTP", "sftp", False, False)
    OPENHAB = ("OpenHAB", "openhab", True, True, 'dashboard')
    NODERED = ("Node-RED", "nodered", False, True, 'ballot')
    POSTGRES = ("Postgre SQL", "postgres", True, False)
    MQTT = ("Mosquitto MQTT Broker", "mqtt", True, False)

    def __init__(self, fullname, prefix, additional, frontend, icon=None):
        self.fullname = fullname
        self.prefix = prefix
        self.additional = additional
        self.frontend = frontend
        self.icon = icon
# >>>


# ******************************
# Compose file functions <<<
# ******************************

# Functions to generate initial file
def generate_initial_compose(base_dir):
    """Creates the initial compose using the skeleton

    :base_dir: Folder to place configuration files into
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    template_path = base_dir + '/' + TEMPLATE_DIR
    # compose file
    compose = base_path + '/' + COMPOSE_NAME
    # skeleton file
    skeleton = template_path + '/' + SKELETON_NAME

    with open(skeleton, 'r') as skeleton_f, open(compose, 'w+') as compose_f:
        init_content = yaml.load(skeleton_f)
        yaml.dump(init_content, compose_f)


def add_sftp_service(base_dir, hostname, number=0):
    """Generates an sftp entry and adds it to the compose file

    :base_dir: base directory for configuration files
    :hostname: names of host that the services is added to
    :number: increment of exposed port to prevent overlaps
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    # compose file
    compose_path = base_path + '/' + COMPOSE_NAME
    # service name
    service_name = f'sftp_{hostname}'
    # template
    template = get_service_template(base_dir, Service.SFTP.prefix)
    # only label contraint is building
    template['deploy']['placement']['constraints'][0] = (
        f"{CONSTRAINTS['building']} == {hostname}")
    template['ports'] = [f'{2222 + number}:22']

    add_or_update_compose_service(compose_path, service_name, template)


def add_openhab_service(base_dir, hostname):
    """Generates an openhab entry and adds it to the compose file

    :base_dir: base directory for configuration files
    :hostname: names of host that the services is added to
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    # compose file
    compose_path = base_path + '/' + COMPOSE_NAME
    # service name
    service_name = f'openhab_{hostname}'
    # template
    template = get_service_template(base_dir, Service.OPENHAB.prefix)
    # only label contraint is building
    template['deploy']['placement']['constraints'][0] = (
        f"{CONSTRAINTS['building']} == {hostname}")
    # include in backups of this building
    template['deploy']['labels'].append(f'backup={hostname}')
    # traefik backend
    template['deploy']['labels'].append(f'traefik.backend={service_name}')
    # traefik frontend domain->openhab
    template['deploy']['labels'].extend(
        generate_traefik_host_labels(hostname, segment='main'))
    # traefik frontend subdomain openhab_hostname.* -> openhab
    template['deploy']['labels'].append(
        f'traefik.sub.frontend.rule=HostRegexp:'
        f'{service_name}.{{domain:[a-zA-z0-9-]+}}')
    template['deploy']['labels'].append('traefik.sub.frontend.priority=2')

    add_or_update_compose_service(compose_path, service_name, template)


def add_nodered_service(base_dir, hostname):
    """Generates an nodered entry and adds it to the compose file

    :base_dir: base directory for configuration files
    :hostname: names of host that the services is added to
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    # compose file
    compose_path = base_path + '/' + COMPOSE_NAME
    # service name
    service_name = f'nodered_{hostname}'
    # template
    template = get_service_template(base_dir, Service.NODERED.prefix)
    # only label contraint is building
    template['deploy']['placement']['constraints'][0] = (
        f"{CONSTRAINTS['building']} == {hostname}")
    template['deploy']['labels'].append(f'traefik.backend={service_name}')
    template['deploy']['labels'].append(f'backup={hostname}')
    template['deploy']['labels'].extend(
        generate_traefik_path_labels(service_name, segment='main'))
    template['deploy']['labels'].extend(
        generate_traefik_subdomain_labels(service_name, segment='sub'))

    add_or_update_compose_service(compose_path, service_name, template)


def add_mqtt_service(base_dir, hostname, number=0):
    """Generates an mqtt entry and adds it to the compose file

    :base_dir: base directory for configuration files
    :hostname: names of host that the services is added to
    :number: increment of exposed port to prevent overlaps
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    # compose file
    compose_path = base_path + '/' + COMPOSE_NAME
    # service name
    service_name = f'mqtt_{hostname}'
    # template
    template = get_service_template(base_dir, Service.MQTT.prefix)
    # only label contraint is building
    template['deploy']['placement']['constraints'][0] = (
        f"{CONSTRAINTS['building']} == {hostname}")
    # ports incremented by number of services
    template['ports'] = [f'{1883 + number}:1883', f'{9001 + number}:9001']

    add_or_update_compose_service(compose_path, service_name, template)


def add_postgres_service(base_dir, hostname, postfix=None):
    """Generates an postgres entry and adds it to the compose file

    :base_dir: base directory for configuration files
    :hostname: names of host that the services is added to
    :postfix: an identifier for this service
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    # compose file
    compose_path = base_path + '/' + COMPOSE_NAME
    # use hostname as postfix when empty
    postfix = hostname if postfix is None else postfix
    # service name
    service_name = f'postgres_{postfix}'
    # template
    template = get_service_template(base_dir, Service.POSTGRES.prefix)
    # only label constraint is building
    template['deploy']['placement']['constraints'][0] = (
        f"{CONSTRAINTS['building']} == {hostname}")

    add_or_update_compose_service(compose_path, service_name, template)


# Functions to delete services
def delete_service(base_dir, service_name):
    """Deletes a service from the compose file

    :base_dir: dir to find files in
    :returns: list of current services
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    # compose file
    compose_path = base_path + '/' + COMPOSE_NAME
    with open(compose_path, 'r+') as compose_f:
        # load compose file
        compose = yaml.load(compose_f)
        # generate list of names
        compose['services'].pop(service_name, None)
        # start writing from file start
        compose_f.seek(0)
        # write new compose content
        yaml.dump(compose, compose_f)
        # reduce file to new size
        compose_f.truncate()


# Functions to extract information
def get_current_services(base_dir):
    """Gets a list of currently used services

    :base_dir: dir to find files in
    :returns: list of current services
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    # compose file
    compose_path = base_path + '/' + COMPOSE_NAME
    with open(compose_path, 'r') as compose_f:
        # load compose file
        compose = yaml.load(compose_f)
        # generate list of names
        service_names = [n for n in compose['services']]
        return service_names


# Helper functions
def get_service_template(base_dir, service_name):
    """Gets a service template entry from the template yaml

    :return: yaml entry of a service
    """
    template_path = base_dir + '/' + TEMPLATE_DIR
    templates = template_path + '/' + TEMPLATES_NAME

    with open(templates, 'r') as templates_file:
        template_content = yaml.load(templates_file)

    return template_content['services'][service_name]


def generate_traefik_host_labels(hostname, segment=None, priority=1):
    """Generates a traefik path url with necessary redirects

    :hostname: Hostname that gets assigned by the label
    :segment: Optional traefik segment when using multiple rules
    :priority: Priority of frontend rule
    :returns: list of labels for traefik
    """
    label_list = []
    # check segment
    segment = f'.{segment}' if segment is not None else ''
    # fill list
    label_list.append(
        f'traefik{segment}.frontend.rule=HostRegexp:{{domain:{hostname}}}')
    label_list.append(f'traefik{segment}.frontend.priority={priority}')
    return label_list


def generate_traefik_subdomain_labels(subdomain, segment=None, priority=2):
    """Generates a traefik subdomain with necessary redirects

    :subdomain: subdomain that will be assigned to a service
    :segment: Optional traefik segment when using multiple rules
    :priority: Priority of frontend rule
    :returns: list of labels for traefik
    """
    label_list = []
    # check segment
    segment = f'.{segment}' if segment is not None else ''
    # fill list
    label_list.append(
        f'traefik{segment}.frontend.rule='
        f'HostRegexp:{subdomain}.{{domain:[a-zA-z0-9-]+}}')
    label_list.append(f'traefik{segment}.frontend.priority={priority}')
    return label_list


def generate_traefik_path_labels(url_path, segment=None, priority=2):
    """Generates a traefik path url with necessary redirects

    :url_path: path that should be used for the site
    :segment: Optional traefik segment when using multiple rules
    :priority: Priority of frontend rule
    :returns: list of labels for traefik
    """
    label_list = []
    # check segment
    segment = f'.{segment}' if segment is not None else ''
    # fill list
    label_list.append(f'traefik{segment}.frontend.priority={priority}')
    label_list.append(
        f'traefik{segment}.frontend.redirect.regex=^(.*)/{url_path}$$')
    label_list.append(
        f'traefik{segment}.frontend.redirect.replacement=$$1/{url_path}/')
    label_list.append(
        f'traefik{segment}.frontend.rule=PathPrefix:/{url_path};'
        f'ReplacePathRegex:^/{url_path}/(.*) /$$1')
    return label_list


def add_or_update_compose_service(compose_path, service_name, service_content):
    """Adds or replaces a service in a compose file

    :compose_path: path of the compose file to change
    :service_name: name of the service to add/replace
    :service_content: service definition to add
    """
    with open(compose_path, 'r+') as compose_f:
        # load compose file
        compose = yaml.load(compose_f)
        # add / update service with template
        compose['services'][service_name] = service_content
        # write content starting from first line
        compose_f.seek(0)
        # write new compose content
        yaml.dump(compose, compose_f)
        # reduce file to new size
        compose_f.truncate()
# >>>


# ******************************
# Config file functions <<<
# ******************************
def generate_config_folders(base_dir):
    """Generate folders for configuration files

    :base_dir: Path to add folders to
    """
    base_path = base_dir + '/' + CUSTOM_DIR
    if not os.path.exists(base_dir):
        os.makedirs(base_dir)

    print(f'Initialize configuration in {base_path}')

    # generate empty config dirs
    for d in CONFIG_DIRS:
        new_dir = base_path + '/' + d
        if not os.path.exists(new_dir):
            os.makedirs(new_dir)

    # copy template configs
    for template_file in TEMPLATE_FILES:
        copy_template_config(base_dir, template_file)


def copy_template_config(base_dir, config_path):
    """Copies template configuration files into custom folder

    :base_dir: path that contains template and custom folders
    :config_path: relative path of config to copy from template
    """
    custom_path = base_dir + '/' + CUSTOM_DIR + "/" + config_path
    template_path = base_dir + '/' + TEMPLATE_DIR + "/" + config_path

    logging.info(f'Copy {config_path} from {custom_path} to {template_path}')
    copy2(template_path, custom_path)


def generate_mosquitto_user_line(username, password):
    """Generates a line for a mosquitto user with a crypt hashed password

    :username: username to use
    :password: password that will be hashed (SHA512)

    :returns: a line as expected by mosquitto
    """
    password_hash = crypt.crypt(password, crypt.mksalt(crypt.METHOD_SHA512))
    line = f"{username}:{password_hash}"
    return line


def generate_sftp_user_line(username, password, directories=None):
    """Generates a line for a sftp user with a hashed password

    :username: username to use
    :password: password that will be hashed (SHA512)
    :directories: list of directories which the user should have

    :returns: a line as expected by sshd
    """
    # generate user line with hashed password
    password_hash = crypt.crypt(password, crypt.mksalt(crypt.METHOD_SHA512))
    line = f"{username}:{password_hash}:e:{UID}:{UID}"
    # add directory entries when available
    if directories:
        # create comma separated string from list
        dir_line = ','.join(d for d in directories)
        line = f"{line}:{dir_line}"
    return line


def generate_traefik_user_line(username, password):
    """Generates a line for a traefik user with a bcrypt hashed password

    :username: username to use
    :password: password that will be hashed (bcrypt)

    :returns: a line as expected by traefik
    """
    password_hash = bcrypt.hashpw(password.encode(), bcrypt.gensalt())
    line = f"{username}:{password_hash.decode()}"
    return line


def generate_pb_framr_entry(host, service):
    """Generates a single entry of the framr file

    :host: host this entry is intended for
    :service: entry from service enum
    :returns: a dict fitting the asked entry

    """
    entry = {}
    entry['title'] = service.fullname
    if service == Service.OPENHAB:
        entry['url'] = f'http://{host}/'
        pass
    else:
        entry['url'] = f'/{service.prefix}_{host}'
    entry['icon'] = service.icon
    return entry


def generate_mosquitto_file(base_dir, username, password):
    """Generates a mosquitto password file using mosquitto_passwd system tool

    :base_dir: path that contains custom config folder
    :username: username to use
    :password: password that will be used
    """
    passwd_path = base_dir + '/' + CUSTOM_DIR + "/" + EDIT_FILES[
        'mosquitto_passwords']

    # ensure file exists
    if not os.path.exists(passwd_path):
        open(passwd_path, 'a').close()

    # execute mosquitto passwd
    mos_result = run(
        ['mosquitto_passwd', '-b', passwd_path, username, password],
        universal_newlines=True)
    return mos_result.returncode == 0


def generate_sftp_file(base_dir, username, password, direcories=None):
    """Generates a sftp password file

    :base_dir: path that contains custom config folder
    :username: username to use
    :password: password that will be used
    :directories: list of directories which the user should have
    """
    # generate line and save it into a file
    file_content = generate_sftp_user_line(username, password, direcories)
    create_or_replace_config_file(base_dir, EDIT_FILES['sftp_users'],
                                  file_content)


def generate_postgres_files(base_dir, username, password):
    """Generates postgres user and password files

    :base_dir: path that contains custom config folder
    :username: username to use
    :password: password that will be used
    """
    # content is purely username and (hashed) password
    hashed_password = 'md5' + \
        md5(username.encode() + password.encode()).hexdigest()
    create_or_replace_config_file(
        base_dir, EDIT_FILES['postgres_user'], username)
    create_or_replace_config_file(
        base_dir, EDIT_FILES['postgres_passwd'], hashed_password)


def generate_id_rsa_files(base_dir):
    """Generates id_rsa and id_rsa.pub private/public keys using ssh-keygen

    :base_dir: path that contains custom config folder
    """
    id_path = base_dir + '/' + CUSTOM_DIR + "/" + EDIT_FILES['id_rsa']

    # execute ssh-keygen
    id_result = run(
        ['ssh-keygen', '-t', 'rsa', '-b', '4096', '-f', id_path, '-N', ''],
        universal_newlines=True, stdout=PIPE)
    return id_result.returncode == 0


def generate_host_key_files(base_dir, hosts):
    """Generates ssh host keys and matching known_hosts using ssh-keygen

    :base_dir: path that contains custom config folder
    """
    key_path = base_dir + '/' + CUSTOM_DIR + "/" + EDIT_FILES['host_key']
    # ssh-keygen generates public key with .pub postfix
    pub_path = key_path + '.pub'
    # host_names with sftp_ postfix
    sftp_hosts = [f'sftp_{host}' for host in hosts]

    # execute ssh-keygen
    id_result = run(['ssh-keygen', '-t', 'ed25519', '-f', key_path, '-N', ''],
                    universal_newlines=True, stdout=PIPE)

    # read content of public key as known line
    known_line = ""
    with open(pub_path, 'r') as pub_file:
        pub_line = pub_file.readline()
        split_line = pub_line.split()
        # delete last list element
        del split_line[-1]
        # collect sftp hosts as comma separated string
        hosts_line = ','.join(h for h in sftp_hosts)
        split_line.insert(0, hosts_line)
        # collect parts as space separated string
        known_line = ' '.join(sp for sp in split_line)

    # write new known_line file
    create_or_replace_config_file(base_dir, EDIT_FILES['known_hosts'],
                                  known_line)

    return id_result.returncode == 0


def generate_traefik_file(base_dir, username, password):
    """Generates a traefik password file

    :base_dir: path that contains custom config folder
    :username: username to use
    :password: password that will be used
    """
    # generate line and save it into a file
    file_content = generate_traefik_user_line(username, password)
    create_or_replace_config_file(base_dir, EDIT_FILES['traefik_users'],
                                  file_content)


def generate_volumerize_file(base_dir, hosts):
    """Generates config for volumerize backups

    :base_dir: path that contains custom config folder
    :hosts: names of backup hosts
    """
    configs = []

    for h in hosts:
        host_config = {
            'description': f'Backup Server on {h}',
            'url': f'sftp://ohadmin@sftp_{h}://home/ohadmin/backup_data/{h}'
        }
        configs.append(host_config)

    create_or_replace_config_file(
        base_dir, EDIT_FILES['backup_config'], configs, json=True)


def generate_pb_framr_file(base_dir, frames):
    """Generates config for pb framr landing page

    :base_dir: path that contains custom config folder
    :frames: a dict that contains hosts with matching name and services
    """
    configs = []

    for f in frames:
        building = {
            'instance': f['building'],
            'entries': [generate_pb_framr_entry(f['host'], s)
                        for s in f['services'] if s.frontend]
        }
        configs.append(building)

    create_or_replace_config_file(
        base_dir, EDIT_FILES['pb_framr_pages'], configs, json=True)


def create_or_replace_config_file(base_dir, config_path, content, json=False):
    """Creates or replaces a config file with new content

    :base_dir: path that contains custom config folder
    :config_path: relative path of config
    :content: content of the file as a string
    """
    custom_path = base_dir + '/' + CUSTOM_DIR + "/" + config_path
    with open(custom_path, 'w+') as file:
        if json:
            import json
            json.dump(content, file, indent=2)
        else:
            file.write(content)


# Functions to modify existing files
def add_user_to_traefik_file(base_dir, username, password):
    """Adds or modifies user in traefik file

    :base_dir: path that contains custom config folder
    :username: username to use
    :password: password that will be used
    """
    # get current users
    current_users = get_traefik_users(base_dir)
    # ensure to delete old entry if user exists
    users = [u for u in current_users if u['username'] != username]
    # collect existing users lines
    user_lines = []
    for u in users:
        user_lines.append(f"{u['username']}:{u['password']}")
    # add new/modified user
    user_lines.append(generate_traefik_user_line(username, password))
    # generate content
    file_content = "\n".join(user_lines)
    create_or_replace_config_file(base_dir, EDIT_FILES['traefik_users'],
                                  file_content)


def remove_user_from_traefik_file(base_dir, username):
    """Removes user from traefik file

    :base_dir: path that contains custom config folder
    :username: username to delete
    """
    # get current users
    current_users = get_traefik_users(base_dir)
    # ensure to delete entry if user exists
    users = [u for u in current_users if u['username'] != username]
    # collect other user lines
    user_lines = []
    for u in users:
        user_lines.append(f"{u['username']}:{u['password']}")
    # generate content and write file
    file_content = "\n".join(user_lines)
    create_or_replace_config_file(base_dir, EDIT_FILES['traefik_users'],
                                  file_content)


# Functions to get content from files
def get_users_from_files(base_dir):
    """Gets a list of users in files

    :base_dir: dir to find files in
    :returns: list of users
    """
    users = []

    # add treafik users
    users.extend([u['username'] for u in get_traefik_users(base_dir)])

    return users


def get_traefik_users(base_dir):
    """Gets a list of dicts containing users and password hashes

    :base_dir: dir to find files in
    :returns: list of users / password dicts
    """
    users = []

    # get treafik users
    traefik_file = f"{base_dir}/{CUSTOM_DIR}/{EDIT_FILES['traefik_users']}"
    with open(traefik_file, 'r') as file:
        lines = file.read().splitlines()
        for line in lines:
            # username in traefik file is first entry unitl colon
            username = line.split(':')[0]
            password = line.split(':')[1]
            users.append({"username": username, "password": password})
    return users
# >>>


# ******************************
# Docker machine functions <<<
# ******************************
def get_machine_list():
    """Get a list of docker machine names using the docker-machine system command

    :returns: a list of machine names managed by docker-machine
    """
    machine_result = run(['docker-machine', 'ls', '-q'],
                         universal_newlines=True,
                         stdout=PIPE)
    return machine_result.stdout.splitlines()


def check_machine_exists(machine_name):
    """Checks weather a docker machine exists and is available

    :machine_name: Name of the machine to check
    :returns: True when machine is available
    """
    machines = get_machine_list()

    return machine_name in machines


def get_machine_env(machine_name):
    """Gets dict of env settings from a machine

    :machine_name: Name of the machine to check
    :returns: Dict of env variables for this machine
    """
    env_result = run(['docker-machine', 'env', machine_name],
                     universal_newlines=True,
                     stdout=PIPE)

    machine_envs = {}

    lines = env_result.stdout.splitlines()
    for line in lines:
        if 'export' in line:
            assign = line.split('export ', 1)[1]
            env_entry = [a.strip('"') for a in assign.split('=', 1)]
            machine_envs[env_entry[0]] = env_entry[1]
    return machine_envs


def get_machine_ip(machine_name):
    """Asks for the ip of the docker machine

    :machine_name: Name of the machine to use for init
    """
    machine_result = run(['docker-machine', 'ip', machine_name],
                         universal_newlines=True,
                         stdout=PIPE)
    return machine_result.stdout.strip()


def init_swarm_machine(machine_name):
    """Creates a new swarm with the specified machine as leader

    :machine_name: Name of the machine to use for init
    :return: True if swarm init was successful
    """
    machine_ip = get_machine_ip(machine_name)
    init_command = 'docker swarm init --advertise-addr ' + machine_ip
    init_result = run(['docker-machine', 'ssh', machine_name, init_command],
                      universal_newlines=True)
    return init_result.returncode == 0


def join_swarm_machine(machine_name, leader_name):
    """Joins the swarm of the specified leader

    :machine_name: Name of the machine to join a swarm
    :leader_name: Name of the swarm leader machine
    :return: True if join to swarm was successful
    """
    token_command = 'docker swarm join-token manager -q'
    token_result = run(['docker-machine', 'ssh', leader_name, token_command],
                       universal_newlines=True,
                       stdout=PIPE)
    token = token_result.stdout.strip()
    leader_ip = get_machine_ip(leader_name)
    logging.info(f"Swarm leader with ip {leader_ip} uses token {token}")

    join_cmd = f'docker swarm join --token {token} {leader_ip}:{SWARM_PORT}'
    logging.info(f'Machine {machine_name} joins using command {join_cmd}')
    join_result = run(['docker-machine', 'ssh', machine_name, join_cmd],
                      universal_newlines=True)

    return join_result.returncode == 0


def generate_swarm(machines):
    """Generates a swarm, the first machine will be the initial leader

    :machines: list of machines in the swarm
    """
    leader = None
    for machine in machines:
        # init swarm with first machine
        if leader is None:
            leader = machine
            print(f'Create initial swarm with leader {leader}')
            if init_swarm_machine(leader):
                print('Swarm init successful\n')
                assign_label_to_node(leader, 'building',
                                     leader, manager=leader)
        else:
            print(f'Machine {machine} joins swarm of leader {leader}')
            if (join_swarm_machine(machine, leader)):
                print('Joining swarm successful\n')
                assign_label_to_node(machine, 'building',
                                     machine, manager=leader)


# >>>


# ******************************
# Docker client commands <<<
# ******************************
def resolve_service_nodes(service):
    """Returnes nodes running on a specified service

    :service: name or id of a service
    :returns: list of nodes running the service
    """
    node_result = run(['docker', 'service', 'ps', service,
                       '--format', '{{.Node}}',
                       '-f', 'desired-state=running'],
                      universal_newlines=True,
                      stdout=PIPE)
    return node_result.stdout.splitlines()


def get_container_list(manager=None):
    """Return a list of containers running on a machine

    :manager: Docker machine to use for command, otherwise local
    :returns: list of containers
    """
    client = get_docker_client(manager)
    return [c.name for c in client.containers.list()]


def get_service_list(manager=None):
    """Return a list of services managed by a machine

    :manager: Docker machine to use for command, otherwise local
    :returns: list of services
    """
    client = get_docker_client(manager)
    return [s.name for s in client.services.list()]


def assign_label_to_node(nodeid, label, value, manager=None):
    """Assigns a label to a node (e.g. building)

    :nodeid: Id or name of the node
    :label: Label you want to add
    :value: The value to assign to the label
    :manager: Docker machine to use for command, otherwise local
    """
    client = get_docker_client(manager)

    node = client.nodes.get(nodeid)
    spec = node.attrs['Spec']
    spec['Labels'][label] = value
    node.update(spec)
    logging.info(f'Assign label {label} with value {value} to {nodeid}')

    client.close()


def run_command_in_service(service, command, building=None):
    """Runs a command in a service based on its name.
    When no matching container is found or the service name is ambigous
    an error will be displayed and the function exits

    :param service: Name of the service to execute command
    :param command: Command to execute
    :param building: Optional building, make service unambigous (Default: None)
    """

    client = get_docker_client(building)

    # Find containers matching name
    service_name_filter = {"name": service}
    containers = client.containers.list(filters=service_name_filter)

    # Ensure match is unambigous
    if (len(containers) > 1):
        print(f'Found multiple containers matching service name {service}, '
              'ensure service is unambigous')
    elif (len(containers) < 1):
        print(f'Found no matching container for service name {service}')
    else:
        service_container = containers[0]
        print(f'Executing {command} in container {service_container.name}'
              f'({service_container.id}) on building {building}\n')
        command_exec = service_container.exec_run(command)
        print(command_exec.output.decode())
    client.close()


def get_docker_client(manager=None):
    """Returns docker client instance

    :manager: Optional machine to use, local otherwise
    :returns: Docker client instance
    """
    if manager:
        machine_env = get_machine_env(manager)
        client = docker.from_env(environment=machine_env)
    else:
        client = docker.from_env()
    return client
# >>>


# ******************************
# CLI base commands <<<
# ******************************
def init_config_dirs_command(args):
    """Initialize config directories

    :args: parsed commandline arguments
    """
    base_dir = args.base_dir

    if base_dir is None:
        base_dir = os.getcwd()

    # generate basic config folder
    generate_config_folders(base_dir)


def assign_building_command(args):
    """Assigns the role of a building to a node

    :args: parsed commandline arguments
    """
    node = args.node
    building = args.building

    print(f'Assign role of building {building} to node {node}')

    assign_label_to_node(node, 'building', building)


def execute_command(args):
    """Top level function to manage command executions from CLI

    :args: parsed commandline arguments
    """
    service = args.service
    command = " ".join(str(x) for x in args.command)  # list to string
    building = args.building

    run_command_in_service(service, command, building)


def restore_command(args):
    """Top level function to manage command executions from CLI

    :args: parsed commandline arguments
    """
    building = args.building
    target = args.target

    if not check_machine_exists(target):
        print(f'Machine with name {target} not found')
        return