ec2stack/configure.py

#!/usr/bin/env python
# encoding: utf-8

"""This module provides functions to generate an ec2stack configuration file.
"""

import os
import argparse

from alembic import command
from ConfigParser import SafeConfigParser
from alembic.config import Config as AlembicConfig


def main():
    """
    Entry point into the configuration application.

    """
    config_folder = _create_config_folder()
    _create_config_file(config_folder)
    _create_database()


def _create_config_folder():
    """
    Creates a folder to hold the user's configuration files.

    @return: Path of the configuration folder.
    """
    config_folder = os.path.join(os.path.expanduser('~'), '.ec2stack')
    if not os.path.exists(config_folder):
        os.makedirs(config_folder)
    os.chmod(config_folder, 0700)
    return config_folder


def _create_config_file(config_folder):
    """
    Reads in configuration items and writes them out to the configuration file.

    @param config_folder: Path of the configuration folder.
    """
    args = _generate_args()
    profile = args.pop('profile')
    config_file_path = config_folder + '/ec2stack.conf'
    config = _modify_config_profile(config_file_path, profile)
    config_file = open(config_file_path, 'w+')
    config.write(config_file)


def _generate_args():
    """
    Generate command line arguments for ec2stack-configure.
    """
    parser = argparse.ArgumentParser(
        'Command line utility for configuring ec2stack'
    )

    parser.add_argument(
        '-p',
        '--profile',
        required=False,
        help='The profile to configure, default is initial',
        default='initial'
    )

    args = parser.parse_args()

    return vars(args)


def _modify_config_profile(config_file, profile):
    """
    Modify configuration profile.
    """
    config = SafeConfigParser()
    config.read(config_file)

    if not config.has_section(profile):
        config.add_section(profile)

    config = _set_attribute_of_profile(
        config, profile, 'ec2stack_bind_address', 'EC2Stack bind address', 'localhost'
    )
    config = _set_attribute_of_profile(
        config, profile, 'ec2stack_port', 'EC2Stack bind port', '5000'
    )
    config = _set_attribute_of_profile(
        config, profile, 'cloudstack_host', 'Cloudstack host', 'localhost'
    )
    config = _set_attribute_of_profile(
        config, profile, 'cloudstack_port', 'Cloudstack port', '8080'
    )
    config = _set_attribute_of_profile(
        config, profile, 'cloudstack_protocol', 'Cloudstack protocol', 'http'
    )
    config = _set_attribute_of_profile(
        config, profile, 'cloudstack_path', 'Cloudstack path', '/client/api'
    )
    config = _set_attribute_of_profile(
        config, profile, 'cloudstack_custom_disk_offering', 'Cloudstack custom disk offering name', 'Custom'
    )

    while True:
        config = _set_attribute_of_profile(
            config, profile, 'cloudstack_default_zone', 'Cloudstack default zone name', ''
        )
        if config.get(profile, 'cloudstack_default_zone') is not '':
            break

    config = _set_optional_attributes_of_profile(config, profile)

    return config


def _set_optional_attributes_of_profile(config, profile):
    """
    Modify optional attributes of profile.
    """
    configure_instance_type_mapings = raw_input(
        'Do you wish to input instance type mappings? (Yes/No): '
    )

    if configure_instance_type_mapings.lower() in ['yes', 'y']:
        config = _read_user_instance_mappings(config, profile)

    configure_resource_type_mapings = raw_input(
        'Do you wish to input resource type to resource id mappings'
        + ' for tag support? (Yes/No): '
    )

    if configure_resource_type_mapings.lower() in ['yes', 'y']:
        config = _read_user_resource_type_mappings(config, profile)

    return config


def _read_user_instance_mappings(config, profile):
    """
    Add instance type mappings to profile.
    """
    instance_section = profile + "instancemap"
    if not config.has_section(instance_section):
        config.add_section(instance_section)

    while True:
        key = raw_input(
            'Insert the AWS EC2 instance type you wish to map: '
        )

        value = raw_input(
            'Insert the name of the instance type you wish to map this to: '
        )

        config.set(instance_section, key, value)

        add_more = raw_input(
            'Do you wish to add more mappings? (Yes/No): ')
        if add_more.lower() in ['no', 'n']:
            break

    return config


def _read_user_resource_type_mappings(config, profile):
    """
    Add resource type mappings to profile.
    """
    resource_section = profile + "resourcemap"
    if not config.has_section(resource_section):
        config.add_section(resource_section)

    while True:
        key = raw_input(
            'Insert the cloudstack resource id you wish to map: '
        )

        value = raw_input(
            'Insert the cloudstack resource type you wish to map this to: '
        )

        config.set(resource_section, key, value)

        add_more = raw_input(
            'Do you wish to add more mappings? (Yes/No): ')
        if add_more.lower() in ['no', 'n']:
            break

    return config


def _set_attribute_of_profile(config, profile, attribute, message, default):
    if config.has_option(profile, attribute):
        default = config.get(profile, attribute)

    attribute_value = _read_in_config_attribute_or_use_default(message, default)

    config.set(profile, attribute, attribute_value)
    return config


def _read_in_config_attribute_or_use_default(message, default):
    attribute = raw_input(message + ' [' + default + ']: ')
    if attribute == '':
        attribute = default

    return attribute


def _create_database():
    """
    Creates/Updates the database.
    """
    directory = os.path.join(os.path.dirname(__file__), '../migrations')
    config = AlembicConfig(os.path.join(
        directory,
        'alembic.ini'
    ))
    config.set_main_option('script_location', directory)
    command.upgrade(config, 'head', sql=False, tag=None)