python-novaclient/novaclient/shell.py

# Copyright 2010 Jacob Kaplan-Moss

# Copyright 2011 OpenStack LLC.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

"""
Command-line interface to the OpenStack Nova API.
"""

import argparse
import glob
import httplib2
import imp
import os
import sys

from novaclient import base
from novaclient import exceptions as exc
from novaclient import utils
from novaclient.v1_0 import shell as shell_v1_0
from novaclient.v1_1 import shell as shell_v1_1


def env(e):
    return os.environ.get(e, '')


class OpenStackComputeShell(object):

    def get_base_parser(self):
        parser = argparse.ArgumentParser(
            prog='nova',
            description=__doc__.strip(),
            epilog='See "nova help COMMAND" '\
                   'for help on a specific command.',
            add_help=False,
            formatter_class=OpenStackHelpFormatter,
        )

        # Global arguments
        parser.add_argument('-h', '--help',
            action='help',
            help=argparse.SUPPRESS,
        )

        parser.add_argument('--debug',
            default=False,
            action='store_true',
            help=argparse.SUPPRESS)

        parser.add_argument('--username',
            default=env('NOVA_USERNAME'),
            help='Defaults to env[NOVA_USERNAME].')

        parser.add_argument('--apikey',
            default=env('NOVA_API_KEY'),
            help='Defaults to env[NOVA_API_KEY].')

        parser.add_argument('--password',
            default=env('NOVA_PASSWORD'),
            help='Defaults to env[NOVA_PASSWORD].')

        parser.add_argument('--projectid',
            default=env('NOVA_PROJECT_ID'),
            help='Defaults to env[NOVA_PROJECT_ID].')

        parser.add_argument('--url',
            default=env('NOVA_URL'),
            help='Defaults to env[NOVA_URL].')

        parser.add_argument('--region_name',
            default=env('NOVA_REGION_NAME'),
            help='Defaults to env[NOVA_REGION_NAME].')

        parser.add_argument('--endpoint_name',
            default=env('NOVA_ENDPOINT_NAME'),
            help='Defaults to env[NOVA_ENDPOINT_NAME] or "publicURL.')

        parser.add_argument('--version',
            default=env('NOVA_VERSION'),
            help='Accepts 1.0 or 1.1, defaults to env[NOVA_VERSION].')

        parser.add_argument('--insecure',
            default=False,
            action='store_true',
            help=argparse.SUPPRESS)

        return parser

    def get_subcommand_parser(self, version, extensions):
        parser = self.get_base_parser()

        self.subcommands = {}
        subparsers = parser.add_subparsers(metavar='<subcommand>')

        try:
            actions_module = {
                '1': shell_v1_0,
                '1.0': shell_v1_0,
                '1.1': shell_v1_1,
                '2': shell_v1_1,
            }[version]
        except KeyError:
            actions_module = shell_v1_0

        self._find_actions(subparsers, actions_module)
        self._find_actions(subparsers, self)

        for _, _, ext_module in extensions:
            self._find_actions(subparsers, ext_module)

        self._add_bash_completion_subparser(subparsers)

        return parser

    def _discover_extensions(self, version):
        module_path = os.path.dirname(os.path.abspath(__file__))
        version_str = "v%s" % version.replace('.', '_')
        ext_path = os.path.join(module_path, version_str, 'contrib')
        ext_glob = os.path.join(ext_path, "*.py")

        extensions = []
        for ext_path in glob.iglob(ext_glob):
            name = os.path.basename(ext_path)[:-3]
            ext_module = imp.load_source(name, ext_path)

            # Extract Manager class
            ext_manager_class = None
            for attr_value in ext_module.__dict__.values():
                try:
                    if issubclass(attr_value, base.Manager):
                        ext_manager_class = attr_value
                        break
                except TypeError:
                    continue  # in case attr_value isn't a class...

            if not ext_manager_class:
                raise Exception("Could not find Manager class in extension.")

            extensions.append((name, ext_manager_class, ext_module))

        return extensions

    def _add_bash_completion_subparser(self, subparsers):
        subparser = subparsers.add_parser('bash_completion',
            add_help=False,
            formatter_class=OpenStackHelpFormatter
        )
        self.subcommands['bash_completion'] = subparser
        subparser.set_defaults(func=self.do_bash_completion)

    def _find_actions(self, subparsers, actions_module):
        for attr in (a for a in dir(actions_module) if a.startswith('do_')):
            # I prefer to be hypen-separated instead of underscores.
            command = attr[3:].replace('_', '-')
            callback = getattr(actions_module, attr)
            desc = callback.__doc__ or ''
            help = desc.strip().split('\n')[0]
            arguments = getattr(callback, 'arguments', [])

            subparser = subparsers.add_parser(command,
                help=help,
                description=desc,
                add_help=False,
                formatter_class=OpenStackHelpFormatter
            )
            subparser.add_argument('-h', '--help',
                action='help',
                help=argparse.SUPPRESS,
            )
            self.subcommands[command] = subparser
            for (args, kwargs) in arguments:
                subparser.add_argument(*args, **kwargs)
            subparser.set_defaults(func=callback)

    def main(self, argv):
        # Parse args once to find version
        parser = self.get_base_parser()
        (options, args) = parser.parse_known_args(argv)

        # build available subcommands based on version
        extensions = self._discover_extensions(options.version)
        subcommand_parser = self.get_subcommand_parser(
                options.version, extensions)
        self.parser = subcommand_parser

        # Parse args again and call whatever callback was selected
        args = subcommand_parser.parse_args(argv)

        # Deal with global arguments
        if args.debug:
            httplib2.debuglevel = 1

        # Short-circuit and deal with help right away.
        if args.func == self.do_help:
            self.do_help(args)
            return 0
        elif args.func == self.do_bash_completion:
            self.do_bash_completion(args)
            return 0

        (user, apikey, password, projectid, url, region_name,
                endpoint_name, insecure) = (args.username, args.apikey,
                        args.password, args.projectid, args.url,
                        args.region_name, args.endpoint_name, args.insecure)

        if not endpoint_name:
            endpoint_name = 'publicURL'

        #FIXME(usrleon): Here should be restrict for project id same as
        # for username or password but for compatibility it is not.

        if not user:
            raise exc.CommandError("You must provide a username, either "
                                   "via --username or via "
                                   "env[NOVA_USERNAME]")

        if not password:
            if not apikey:
                raise exc.CommandError("You must provide a password, either "
                        "via --password or via env[NOVA_PASSWORD]")
            else:
                password = apikey

        if options.version and options.version != '1.0':
            if not projectid:
                raise exc.CommandError("You must provide an projectid, either "
                                       "via --projectid or via "
                                       "env[NOVA_PROJECT_ID")

            if not url:
                raise exc.CommandError("You must provide a auth url, either "
                                       "via --url or via "
                                       "env[NOVA_URL")

        self.cs = self.get_api_class(options.version)(user, password,
                                     projectid, url, insecure,
                                     region_name=region_name,
                                     endpoint_name=endpoint_name,
                                     extensions=extensions)

        try:
            self.cs.authenticate()
        except exc.Unauthorized:
            raise exc.CommandError("Invalid OpenStack Nova credentials.")
        except exc.AuthorizationFailure:
            raise exc.CommandError("Unable to authorize user")

        args.func(self.cs, args)

    def get_api_class(self, version):
        try:
            return {
                "1": shell_v1_0.CLIENT_CLASS,
                "1.0": shell_v1_0.CLIENT_CLASS,
                "1.1": shell_v1_1.CLIENT_CLASS,
                "2": shell_v1_1.CLIENT_CLASS,
            }[version]
        except KeyError:
            return shell_v1_0.CLIENT_CLASS

    def do_bash_completion(self, args):
        """
        Prints all of the commands and options to stdout so that the
        nova.bash_completion script doesn't have to hard code them.
        """
        commands = set()
        options = set()
        for sc_str, sc in self.subcommands.items():
            commands.add(sc_str)
            for option in sc._optionals._option_string_actions.keys():
                options.add(option)

        commands.remove('bash-completion')
        commands.remove('bash_completion')
        print ' '.join(commands | options)

    @utils.arg('command', metavar='<subcommand>', nargs='?',
                    help='Display help for <subcommand>')
    def do_help(self, args):
        """
        Display help about this program or one of its subcommands.
        """
        if args.command:
            if args.command in self.subcommands:
                self.subcommands[args.command].print_help()
            else:
                raise exc.CommandError("'%s' is not a valid subcommand" %
                                       args.command)
        else:
            self.parser.print_help()


# I'm picky about my shell help.
class OpenStackHelpFormatter(argparse.HelpFormatter):
    def start_section(self, heading):
        # Title-case the headings
        heading = '%s%s' % (heading[0].upper(), heading[1:])
        super(OpenStackHelpFormatter, self).start_section(heading)


def main():
    try:
        OpenStackComputeShell().main(sys.argv[1:])

    except Exception, e:
        if httplib2.debuglevel == 1:
            raise  # dump stack.
        else:
            print >> sys.stderr, e
        sys.exit(1)