# Copyright 2016 The Kubernetes Authors. # # 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 atexit import base64 import datetime import os import tempfile import google.auth import google.auth.transport.requests import urllib3 import yaml from kubernetes.client import ApiClient, ConfigurationObject, configuration from .config_exception import ConfigException from .dateutil import UTC, format_rfc3339, parse_rfc3339 EXPIRY_SKEW_PREVENTION_DELAY = datetime.timedelta(minutes=5) KUBE_CONFIG_DEFAULT_LOCATION = os.environ.get('KUBECONFIG', '~/.kube/config') _temp_files = {} def _cleanup_temp_files(): global _temp_files for temp_file in _temp_files.values(): try: os.remove(temp_file) except OSError: pass _temp_files = {} def _create_temp_file_with_content(content): if len(_temp_files) == 0: atexit.register(_cleanup_temp_files) # Because we may change context several times, try to remember files we # created and reuse them at a small memory cost. content_key = str(content) if content_key in _temp_files: return _temp_files[content_key] _, name = tempfile.mkstemp() _temp_files[content_key] = name with open(name, 'wb') as fd: fd.write(content.encode() if isinstance(content, str) else content) return name def _is_expired(expiry): return ((parse_rfc3339(expiry) + EXPIRY_SKEW_PREVENTION_DELAY) <= datetime.datetime.utcnow().replace(tzinfo=UTC)) class FileOrData(object): """Utility class to read content of obj[%data_key_name] or file's content of obj[%file_key_name] and represent it as file or data. Note that the data is preferred. The obj[%file_key_name] will be used iff obj['%data_key_name'] is not set or empty. Assumption is file content is raw data and data field is base64 string. The assumption can be changed with base64_file_content flag. If set to False, the content of the file will assumed to be base64 and read as is. The default True value will result in base64 encode of the file content after read.""" def __init__(self, obj, file_key_name, data_key_name=None, file_base_path="", base64_file_content=True): if not data_key_name: data_key_name = file_key_name + "-data" self._file = None self._data = None self._base64_file_content = base64_file_content if data_key_name in obj: self._data = obj[data_key_name] elif file_key_name in obj: self._file = os.path.normpath( os.path.join(file_base_path, obj[file_key_name])) def as_file(self): """If obj[%data_key_name] exists, return name of a file with base64 decoded obj[%data_key_name] content otherwise obj[%file_key_name].""" use_data_if_no_file = not self._file and self._data if use_data_if_no_file: if self._base64_file_content: self._file = _create_temp_file_with_content( base64.decodestring(self._data.encode())) else: self._file = _create_temp_file_with_content(self._data) if self._file and not os.path.isfile(self._file): raise ConfigException("File does not exists: %s" % self._file) return self._file def as_data(self): """If obj[%data_key_name] exists, Return obj[%data_key_name] otherwise base64 encoded string of obj[%file_key_name] file content.""" use_file_if_no_data = not self._data and self._file if use_file_if_no_data: with open(self._file) as f: if self._base64_file_content: self._data = bytes.decode( base64.encodestring(str.encode(f.read()))) else: self._data = f.read() return self._data class KubeConfigLoader(object): def __init__(self, config_dict, active_context=None, get_google_credentials=None, client_configuration=configuration, config_base_path="", config_persister=None): self._config = ConfigNode('kube-config', config_dict) self._current_context = None self._user = None self._cluster = None self.set_active_context(active_context) self._config_base_path = config_base_path self._config_persister = config_persister def _refresh_credentials(): credentials, project_id = google.auth.default() request = google.auth.transport.requests.Request() credentials.refresh(request) return credentials if get_google_credentials: self._get_google_credentials = get_google_credentials else: self._get_google_credentials = _refresh_credentials self._client_configuration = client_configuration def set_active_context(self, context_name=None): if context_name is None: context_name = self._config['current-context'] self._current_context = self._config['contexts'].get_with_name( context_name) if (self._current_context['context'].safe_get('user') and self._config.safe_get('users')): user = self._config['users'].get_with_name( self._current_context['context']['user'], safe=True) if user: self._user = user['user'] else: self._user = None else: self._user = None self._cluster = self._config['clusters'].get_with_name( self._current_context['context']['cluster'])['cluster'] def _load_authentication(self): """Read authentication from kube-config user section if exists. This function goes through various authentication methods in user section of kube-config and stops if it finds a valid authentication method. The order of authentication methods is: 1. GCP auth-provider 2. token_data 3. token field (point to a token file) 4. username/password """ if not self._user: return if self._load_gcp_token(): return if self._load_user_token(): return self._load_user_pass_token() def _load_gcp_token(self): if 'auth-provider' not in self._user: return provider = self._user['auth-provider'] if 'name' not in provider: return if provider['name'] != 'gcp': return if (('config' not in provider) or ('access-token' not in provider['config']) or ('expiry' in provider['config'] and _is_expired(provider['config']['expiry']))): # token is not available or expired, refresh it self._refresh_gcp_token() self.token = "Bearer %s" % provider['config']['access-token'] return self.token def _refresh_gcp_token(self): if 'config' not in self._user['auth-provider']: self._user['auth-provider'].value['config'] = {} provider = self._user['auth-provider']['config'] credentials = self._get_google_credentials() provider.value['access-token'] = credentials.token provider.value['expiry'] = format_rfc3339(credentials.expiry) if self._config_persister: self._config_persister(self._config.value) def _load_user_token(self): token = FileOrData( self._user, 'tokenFile', 'token', file_base_path=self._config_base_path, base64_file_content=False).as_data() if token: self.token = "Bearer %s" % token return True def _load_user_pass_token(self): if 'username' in self._user and 'password' in self._user: self.token = urllib3.util.make_headers( basic_auth=(self._user['username'] + ':' + self._user['password'])).get('authorization') return True def _load_cluster_info(self): if 'server' in self._cluster: self.host = self._cluster['server'] if self.host.startswith("https"): self.ssl_ca_cert = FileOrData( self._cluster, 'certificate-authority', file_base_path=self._config_base_path).as_file() self.cert_file = FileOrData( self._user, 'client-certificate', file_base_path=self._config_base_path).as_file() self.key_file = FileOrData( self._user, 'client-key', file_base_path=self._config_base_path).as_file() if 'insecure-skip-tls-verify' in self._cluster: self.verify_ssl = not self._cluster['insecure-skip-tls-verify'] def _set_config(self): if 'token' in self.__dict__: self._client_configuration.api_key['authorization'] = self.token # copy these keys directly from self to configuration object keys = ['host', 'ssl_ca_cert', 'cert_file', 'key_file', 'verify_ssl'] for key in keys: if key in self.__dict__: setattr(self._client_configuration, key, getattr(self, key)) def load_and_set(self): self._load_authentication() self._load_cluster_info() self._set_config() def list_contexts(self): return [context.value for context in self._config['contexts']] @property def current_context(self): return self._current_context.value class ConfigNode(object): """Remembers each config key's path and construct a relevant exception message in case of missing keys. The assumption is all access keys are present in a well-formed kube-config.""" def __init__(self, name, value): self.name = name self.value = value def __contains__(self, key): return key in self.value def __len__(self): return len(self.value) def safe_get(self, key): if (isinstance(self.value, list) and isinstance(key, int) or key in self.value): return self.value[key] def __getitem__(self, key): v = self.safe_get(key) if not v: raise ConfigException( 'Invalid kube-config file. Expected key %s in %s' % (key, self.name)) if isinstance(v, dict) or isinstance(v, list): return ConfigNode('%s/%s' % (self.name, key), v) else: return v def get_with_name(self, name, safe=False): if not isinstance(self.value, list): raise ConfigException( 'Invalid kube-config file. Expected %s to be a list' % self.name) for v in self.value: if 'name' not in v: raise ConfigException( 'Invalid kube-config file. ' 'Expected all values in %s list to have \'name\' key' % self.name) if v['name'] == name: return ConfigNode('%s[name=%s]' % (self.name, name), v) if safe: return None raise ConfigException( 'Invalid kube-config file. ' 'Expected object with name %s in %s list' % (name, self.name)) def _get_kube_config_loader_for_yaml_file(filename, **kwargs): with open(filename) as f: return KubeConfigLoader( config_dict=yaml.load(f), config_base_path=os.path.abspath(os.path.dirname(filename)), **kwargs) def list_kube_config_contexts(config_file=None): if config_file is None: config_file = os.path.expanduser(KUBE_CONFIG_DEFAULT_LOCATION) loader = _get_kube_config_loader_for_yaml_file(config_file) return loader.list_contexts(), loader.current_context def load_kube_config(config_file=None, context=None, client_configuration=configuration, persist_config=True): """Loads authentication and cluster information from kube-config file and stores them in kubernetes.client.configuration. :param config_file: Name of the kube-config file. :param context: set the active context. If is set to None, current_context from config file will be used. :param client_configuration: The kubernetes.client.ConfigurationObject to set configs to. :param persist_config: If True, config file will be updated when changed (e.g GCP token refresh). """ if config_file is None: config_file = os.path.expanduser(KUBE_CONFIG_DEFAULT_LOCATION) config_persister = None if persist_config: def _save_kube_config(config_map): with open(config_file, 'w') as f: yaml.safe_dump(config_map, f, default_flow_style=False) config_persister = _save_kube_config _get_kube_config_loader_for_yaml_file( config_file, active_context=context, client_configuration=client_configuration, config_persister=config_persister).load_and_set() def new_client_from_config( config_file=None, context=None, persist_config=True): """Loads configuration the same as load_kube_config but returns an ApiClient to be used with any API object. This will allow the caller to concurrently talk with multiple clusters.""" client_config = ConfigurationObject() load_kube_config(config_file=config_file, context=context, client_configuration=client_config, persist_config=persist_config) return ApiClient(config=client_config)