| # |
| # Copyright (C) 2019 Bloomberg Finance LP |
| # |
| # This program is free software; you can redistribute it and/or |
| # modify it under the terms of the GNU Lesser General Public |
| # License as published by the Free Software Foundation; either |
| # version 2 of the License, or (at your option) any later version. |
| # |
| # This library is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| # Lesser General Public License for more details. |
| # |
| # You should have received a copy of the GNU Lesser General Public |
| # License along with this library. If not, see <http://www.gnu.org/licenses/>. |
| # |
| |
| import os |
| from collections import namedtuple |
| from urllib.parse import urlparse |
| |
| import grpc |
| |
| from ._exceptions import LoadError, LoadErrorReason, ImplError, RemoteError |
| from .types import FastEnum |
| |
| |
| # RemoteType(): |
| # |
| # Defines the different types of remote. |
| # |
| class RemoteType(FastEnum): |
| INDEX = "index" |
| STORAGE = "storage" |
| ALL = "all" |
| |
| def __str__(self): |
| return self.name.lower().replace('_', '-') |
| |
| |
| # RemoteSpec(): |
| # |
| # Defines the basic structure of a remote specification. |
| # |
| class RemoteSpec(namedtuple('RemoteSpec', 'url push server_cert client_key client_cert instance_name type')): |
| |
| # new_from_config_node |
| # |
| # Creates a RemoteSpec() from a YAML loaded node. |
| # |
| # Args: |
| # spec_node (MappingNode): The configuration node describing the spec. |
| # basedir (str): The base directory from which to find certificates. |
| # |
| # Returns: |
| # (RemoteSpec) - The described RemoteSpec instance. |
| # |
| # Raises: |
| # LoadError: If the node is malformed. |
| # |
| @classmethod |
| def new_from_config_node(cls, spec_node, basedir=None): |
| spec_node.validate_keys(['url', 'push', 'server-cert', 'client-key', 'client-cert', 'instance-name', 'type']) |
| |
| url = spec_node.get_str('url') |
| if not url: |
| provenance = spec_node.get_node('url').get_provenance() |
| raise LoadError("{}: empty artifact cache URL".format(provenance), LoadErrorReason.INVALID_DATA) |
| |
| push = spec_node.get_bool('push', default=False) |
| instance_name = spec_node.get_str('instance-name', default=None) |
| |
| def parse_cert(key): |
| cert = spec_node.get_str(key, default=None) |
| if cert and basedir: |
| cert = os.path.join(basedir, cert) |
| return cert |
| |
| cert_keys = ('server-cert', 'client-key', 'client-cert') |
| server_cert, client_key, client_cert = tuple(parse_cert(key) for key in cert_keys) |
| |
| if client_key and not client_cert: |
| provenance = spec_node.get_node('client-key').get_provenance() |
| raise LoadError("{}: 'client-key' was specified without 'client-cert'".format(provenance), |
| LoadErrorReason.INVALID_DATA) |
| |
| if client_cert and not client_key: |
| provenance = spec_node.get_node('client-cert').get_provenance() |
| raise LoadError("{}: 'client-cert' was specified without 'client-key'".format(provenance), |
| LoadErrorReason.INVALID_DATA) |
| |
| type_ = spec_node.get_enum('type', RemoteType, default=RemoteType.ALL) |
| |
| return cls(url, push, server_cert, client_key, client_cert, instance_name, type_) |
| |
| |
| # FIXME: This can be made much nicer in python 3.7 through the use of |
| # defaults - or hell, by replacing it all with a typing.NamedTuple |
| # |
| # Note that defaults are specified from the right, and ommitted values |
| # are considered mandatory. |
| # |
| # Disable type-checking since "Callable[...] has no attributes __defaults__" |
| RemoteSpec.__new__.__defaults__ = ( # type: ignore |
| # mandatory # url - The url of the remote |
| # mandatory # push - Whether the remote should be used for pushing |
| None, # server_cert - The server certificate |
| None, # client_key - The (private) client key |
| None, # client_cert - The (public) client certificate |
| None, # instance_name - The (grpc) instance name of the remote |
| RemoteType.ALL # type - The type of the remote (index, storage, both) |
| ) |
| |
| |
| # BaseRemote(): |
| # |
| # Provides the basic functionality required to set up remote |
| # interaction via GRPC. In particular, this will set up a |
| # grpc.insecure_channel, or a grpc.secure_channel, based on the given |
| # spec. |
| # |
| # Customization for the particular protocol is expected to be |
| # performed in children. |
| # |
| class BaseRemote(): |
| key_name = None |
| |
| def __init__(self, spec): |
| self.spec = spec |
| self._initialized = False |
| |
| self.channel = None |
| |
| self.server_cert = None |
| self.client_key = None |
| self.client_cert = None |
| |
| self.instance_name = spec.instance_name |
| self.push = spec.push |
| self.url = spec.url |
| |
| # init(): |
| # |
| # Initialize the given remote. This function must be called before |
| # any communication is performed, since such will otherwise fail. |
| # |
| def init(self): |
| if self._initialized: |
| return |
| |
| # Set up the communcation channel |
| url = urlparse(self.spec.url) |
| if url.scheme == 'http': |
| port = url.port or 80 |
| self.channel = grpc.insecure_channel('{}:{}'.format(url.hostname, port)) |
| elif url.scheme == 'https': |
| port = url.port or 443 |
| try: |
| server_cert, client_key, client_cert = _read_files( |
| self.spec.server_cert, |
| self.spec.client_key, |
| self.spec.client_cert) |
| except FileNotFoundError as e: |
| raise RemoteError("Could not read certificates: {}".format(e)) from e |
| self.server_cert = server_cert |
| self.client_key = client_key |
| self.client_cert = client_cert |
| credentials = grpc.ssl_channel_credentials(root_certificates=self.server_cert, |
| private_key=self.client_key, |
| certificate_chain=self.client_cert) |
| self.channel = grpc.secure_channel('{}:{}'.format(url.hostname, port), credentials) |
| else: |
| raise RemoteError("Unsupported URL: {}".format(self.spec.url)) |
| |
| self._configure_protocols() |
| |
| self._initialized = True |
| |
| def __enter__(self): |
| return self |
| |
| def __exit__(self, exc_type, exc_value, traceback): |
| self.close() |
| return False |
| |
| def close(self): |
| if self.channel: |
| self.channel.close() |
| self.channel = None |
| |
| self._initialized = False |
| |
| # _configure_protocols(): |
| # |
| # An abstract method to configure remote-specific protocols. This |
| # is *not* done as super().init() because we want to be able to |
| # set self._initialized *after* initialization completes in the |
| # parent class. |
| # |
| # This method should *never* be called outside of init(). |
| # |
| def _configure_protocols(self): |
| raise ImplError("An implementation of a Remote must configure its protocols.") |
| |
| # check(): |
| # |
| # Check if the remote is functional and has all the required |
| # capabilities. This should be used somewhat like an assertion, |
| # expecting a RemoteError. |
| # |
| # Note that this method runs the calls on a separate process, so |
| # that we can use grpc calls even if we are on the main process. |
| # |
| # Raises: |
| # RemoteError: If the grpc call fails. |
| # |
| def check(self): |
| try: |
| self.init() |
| self._check() |
| except grpc.RpcError as e: |
| # str(e) is too verbose for errors reported to the user |
| raise RemoteError(e.details()) |
| finally: |
| self.close() |
| |
| # _check(): |
| # |
| # Check if this remote provides everything required for the |
| # particular kind of remote. This is expected to be called as part |
| # of check(), and must be called in a non-main process. |
| # |
| # Returns: |
| # (str|None): An error message, or None if no error message. |
| # |
| def _check(self): |
| return None |
| |
| def __str__(self): |
| return self.url |
| |
| |
| # _read_files(): |
| # |
| # A helper method to read a bunch of files, ignoring any input |
| # arguments that are None. |
| # |
| # Args: |
| # files (Iterable[str|None]): A list of files to read. Nones are passed back. |
| # |
| # Returns: |
| # Generator[str|None, None, None] - Strings read from those files. |
| # |
| def _read_files(*files): |
| def read_file(f): |
| if f: |
| with open(f, 'rb') as data: |
| return data.read() |
| return None |
| return (read_file(f) for f in files) |
