keystoneauth/keystoneauth1/adapter.py

# 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.

import os

from positional import positional


class Adapter(object):
    """An instance of a session with local variables.

    A session is a global object that is shared around amongst many clients. It
    therefore contains state that is relevant to everyone. There is a lot of
    state such as the service type and region_name that are only relevant to a
    particular client that is using the session. An adapter provides a wrapper
    of client local data around the global session object.

    :param session: The session object to wrap.
    :type session: keystoneauth1.session.Session
    :param str service_type: The default service_type for URL discovery.
    :param str service_name: The default service_name for URL discovery.
    :param str interface: The default interface for URL discovery.
    :param str region_name: The default region_name for URL discovery.
    :param str endpoint_override: Always use this endpoint URL for requests
                                  for this client.
    :param tuple version: The version that this API targets.
    :param auth: An auth plugin to use instead of the session one.
    :type auth: keystoneauth1.plugin.BaseAuthPlugin
    :param str user_agent: The User-Agent string to set.
    :param int connect_retries: the maximum number of retries that should
                                be attempted for connection errors.
                                Default None - use session default which
                                is don't retry.
    :param logger: A logging object to use for requests that pass through this
                   adapter.
    :type logger: logging.Logger
    :param dict allow: Extra filters to pass when discovering API versions.
                       (optional)
    :param dict additional_headers: Additional headers that should be attached
                                    to every request passing through the
                                    adapter. Headers of the same name specified
                                    per request will take priority.
    """

    @positional()
    def __init__(self, session, service_type=None, service_name=None,
                 interface=None, region_name=None, endpoint_override=None,
                 version=None, auth=None, user_agent=None,
                 connect_retries=None, logger=None, allow={},
                 additional_headers=None):
        # NOTE(jamielennox): when adding new parameters to adapter please also
        # add them to the adapter call in httpclient.HTTPClient.__init__ as
        # well as to load_adapter_from_argparse below if the argument is
        # intended to be something a user would reasonably expect to set on
        # a command line
        self.session = session
        self.service_type = service_type
        self.service_name = service_name
        self.interface = interface
        self.region_name = region_name
        self.endpoint_override = endpoint_override
        self.version = version
        self.user_agent = user_agent
        self.auth = auth
        self.connect_retries = connect_retries
        self.logger = logger
        self.allow = allow
        self.additional_headers = additional_headers or {}

    def _set_endpoint_filter_kwargs(self, kwargs):
        if self.service_type:
            kwargs.setdefault('service_type', self.service_type)
        if self.service_name:
            kwargs.setdefault('service_name', self.service_name)
        if self.interface:
            kwargs.setdefault('interface', self.interface)
        if self.region_name:
            kwargs.setdefault('region_name', self.region_name)
        if self.version:
            kwargs.setdefault('version', self.version)

    def request(self, url, method, **kwargs):
        endpoint_filter = kwargs.setdefault('endpoint_filter', {})
        self._set_endpoint_filter_kwargs(endpoint_filter)

        if self.endpoint_override:
            kwargs.setdefault('endpoint_override', self.endpoint_override)

        if self.auth:
            kwargs.setdefault('auth', self.auth)
        if self.user_agent:
            kwargs.setdefault('user_agent', self.user_agent)
        if self.connect_retries is not None:
            kwargs.setdefault('connect_retries', self.connect_retries)
        if self.logger:
            kwargs.setdefault('logger', self.logger)
        if self.allow:
            kwargs.setdefault('allow', self.allow)

        for k, v in self.additional_headers.items():
            kwargs.setdefault('headers', {}).setdefault(k, v)

        return self.session.request(url, method, **kwargs)

    def get_token(self, auth=None):
        """Return a token as provided by the auth plugin.

        :param auth: The auth plugin to use for token. Overrides the plugin
                     on the session. (optional)
        :type auth: keystoneauth1.plugin.BaseAuthPlugin

        :raises keystoneauth1.exceptions.auth.AuthorizationFailure: if a new
            token fetch fails.

        :returns: A valid token.
        :rtype: :class:`str`
        """
        return self.session.get_token(auth or self.auth)

    def get_endpoint(self, auth=None, **kwargs):
        """Get an endpoint as provided by the auth plugin.

        :param auth: The auth plugin to use for token. Overrides the plugin on
                     the session. (optional)
        :type auth: keystoneauth1.plugin.BaseAuthPlugin

        :raises keystoneauth1.exceptions.auth_plugins.MissingAuthPlugin: if a
            plugin is not available.

        :returns: An endpoint if available or None.
        :rtype: :class:`str`
        """
        if self.endpoint_override:
            return self.endpoint_override

        self._set_endpoint_filter_kwargs(kwargs)
        return self.session.get_endpoint(auth or self.auth, **kwargs)

    def invalidate(self, auth=None):
        """Invalidate an authentication plugin."""
        return self.session.invalidate(auth or self.auth)

    def get_user_id(self, auth=None):
        """Return the authenticated user_id as provided by the auth plugin.

        :param auth: The auth plugin to use for token. Overrides the plugin
                     on the session. (optional)
        :type auth: keystoneauth1.plugin.BaseAuthPlugin

        :raises keystoneauth1.exceptions.auth.AuthorizationFailure:
            if a new token fetch fails.
        :raises keystoneauth1.exceptions.auth_plugins.MissingAuthPlugin:
            if a plugin is not available.

        :returns: Current `user_id` or None if not supported by plugin.
        :rtype: :class:`str`
        """
        return self.session.get_user_id(auth or self.auth)

    def get_project_id(self, auth=None):
        """Return the authenticated project_id as provided by the auth plugin.

        :param auth: The auth plugin to use for token. Overrides the plugin
                     on the session. (optional)
        :type auth: keystoneauth1.plugin.BaseAuthPlugin

        :raises keystoneauth1.exceptions.auth.AuthorizationFailure:
            if a new token fetch fails.
        :raises keystoneauth1.exceptions.auth_plugins.MissingAuthPlugin:
            if a plugin is not available.

        :returns: Current `project_id` or None if not supported by plugin.
        :rtype: :class:`str`
        """
        return self.session.get_project_id(auth or self.auth)

    def get(self, url, **kwargs):
        return self.request(url, 'GET', **kwargs)

    def head(self, url, **kwargs):
        return self.request(url, 'HEAD', **kwargs)

    def post(self, url, **kwargs):
        return self.request(url, 'POST', **kwargs)

    def put(self, url, **kwargs):
        return self.request(url, 'PUT', **kwargs)

    def patch(self, url, **kwargs):
        return self.request(url, 'PATCH', **kwargs)

    def delete(self, url, **kwargs):
        return self.request(url, 'DELETE', **kwargs)

    @classmethod
    def register_argparse_arguments(cls, parser, service_type=None):
        """Attach arguments to a given argparse Parser for Adapters.

        :param parser: The argparse parser to attach options to.
        :type parser: argparse.ArgumentParser
        :param str service_type: Default service_type value. (optional)
        """
        adapter_group = parser.add_argument_group(
            'Service Options',
            'Options controlling the specialization of the API'
            ' Connection from information found in the catalog')

        adapter_group.add_argument(
            '--os-service-type',
            metavar='<name>',
            default=os.environ.get('OS_SERVICE_TYPE', service_type),
            help='Service type to request from the catalog')

        adapter_group.add_argument(
            '--os-service-name',
            metavar='<name>',
            default=os.environ.get('OS_SERVICE_NAME', None),
            help='Service name to request from the catalog')

        adapter_group.add_argument(
            '--os-interface',
            metavar='<name>',
            default=os.environ.get('OS_INTERFACE', 'public'),
            help='API Interface to use [public, internal, admin]')

        adapter_group.add_argument(
            '--os-region-name',
            metavar='<name>',
            default=os.environ.get('OS_REGION_NAME', None),
            help='Region of the cloud to use')

        adapter_group.add_argument(
            '--os-endpoint-override',
            metavar='<name>',
            default=os.environ.get('OS_ENDPOINT_OVERRIDE', None),
            help='Endpoint to use instead of the endpoint in the catalog')

        adapter_group.add_argument(
            '--os-api-version',
            metavar='<name>',
            default=os.environ.get('OS_API_VERSION', None),
            help='Which version of the service API to use')

    @classmethod
    def register_service_argparse_arguments(cls, parser, service_type):
        """Attach arguments to a given argparse Parser for Adapters.

        :param parser: The argparse parser to attach options to.
        :type parser: argparse.ArgumentParser
        :param str service_type: Name of a service to generate additional
                                 arguments for.
        """
        service_env = service_type.upper().replace('-', '_')
        adapter_group = parser.add_argument_group(
            '{service_type} Service Options'.format(
                service_type=service_type.title()),
            'Options controlling the specialization of the {service_type}'
            ' API Connection from information found in the catalog'.format(
                service_type=service_type.title()))

        adapter_group.add_argument(
            '--os-{service_type}-service-type'.format(
                service_type=service_type),
            metavar='<name>',
            default=os.environ.get(
                'OS_{service_type}_SERVICE_TYPE'.format(
                    service_type=service_env), None),
            help=('Service type to request from the catalog for the'
                  ' {service_type} service'.format(
                      service_type=service_type)))

        adapter_group.add_argument(
            '--os-{service_type}-service-name'.format(
                service_type=service_type),
            metavar='<name>',
            default=os.environ.get(
                'OS_{service_type}_SERVICE_NAME'.format(
                    service_type=service_env), None),
            help=('Service name to request from the catalog for the'
                  ' {service_type} service'.format(
                      service_type=service_type)))

        adapter_group.add_argument(
            '--os-{service_type}-interface'.format(
                service_type=service_type),
            metavar='<name>',
            default=os.environ.get(
                'OS_{service_type}_INTERFACE'.format(
                    service_type=service_env), None),
            help=('API Interface to use for the {service_type} service'
                  ' [public, internal, admin]'.format(
                      service_type=service_type)))

        adapter_group.add_argument(
            '--os-{service_type}-api-version'.format(
                service_type=service_type),
            metavar='<name>',
            default=os.environ.get(
                'OS_{service_type}_API_VERSION'.format(
                    service_type=service_env), None),
            help=('Which version of the service API to use for'
                  ' the {service_type} service'.format(
                      service_type=service_type)))

        adapter_group.add_argument(
            '--os-{service_type}-endpoint-override'.format(
                service_type=service_type),
            metavar='<name>',
            default=os.environ.get(
                'OS_{service_type}_ENDPOINT_OVERRIDE'.format(
                    service_type=service_env), None),
            help=('Endpoint to use for the {service_type} service'
                  ' instead of the endpoint in the catalog'.format(
                      service_type=service_type)))


class LegacyJsonAdapter(Adapter):
    """Make something that looks like an old HTTPClient.

    A common case when using an adapter is that we want an interface similar to
    the HTTPClients of old which returned the body as JSON as well.

    You probably don't want this if you are starting from scratch.
    """

    def request(self, *args, **kwargs):
        headers = kwargs.setdefault('headers', {})
        headers.setdefault('Accept', 'application/json')

        try:
            kwargs['json'] = kwargs.pop('body')
        except KeyError:
            pass

        resp = super(LegacyJsonAdapter, self).request(*args, **kwargs)

        try:
            body = resp.json()
        except ValueError:
            body = None

        return resp, body


def register_adapter_argparse_arguments(*args, **kwargs):
    return Adapter.register_argparse_arguments(*args, **kwargs)


def register_service_adapter_argparse_arguments(*args, **kwargs):
    return Adapter.register_service_argparse_arguments(*args, **kwargs)