# Copyright 2018 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 copy import datetime import json import logging import os import platform import subprocess import tempfile import time from collections import namedtuple import google.auth import google.auth.transport.requests import oauthlib.oauth2 import urllib3 import yaml from requests_oauthlib import OAuth2Session from six import PY3 from kubernetes.client import ApiClient, Configuration from kubernetes.config.exec_provider import ExecProvider from .config_exception import ConfigException from .dateutil import UTC, format_rfc3339, parse_rfc3339 try: import adal except ImportError: pass EXPIRY_SKEW_PREVENTION_DELAY = datetime.timedelta(minutes=5) KUBE_CONFIG_DEFAULT_LOCATION = os.environ.get('KUBECONFIG', '~/.kube/config') ENV_KUBECONFIG_PATH_SEPARATOR = ';' if platform.system() == 'Windows' else ':' _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, temp_file_path=None): 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] if temp_file_path and not os.path.isdir(temp_file_path): os.makedirs(name=temp_file_path) fd, name = tempfile.mkstemp(dir=temp_file_path) os.close(fd) _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.now(tz=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, temp_file_path=None): 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 self._temp_file_path = temp_file_path if not obj: return 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: if isinstance(self._data, str): content = self._data.encode() else: content = self._data self._file = _create_temp_file_with_content( base64.standard_b64decode(content), self._temp_file_path) else: self._file = _create_temp_file_with_content( self._data, self._temp_file_path) if self._file and not os.path.isfile(self._file): raise ConfigException("File does not exist: %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.standard_b64encode(str.encode(f.read()))) else: self._data = f.read() return self._data class CommandTokenSource(object): def __init__(self, cmd, args, tokenKey, expiryKey): self._cmd = cmd self._args = args if not tokenKey: self._tokenKey = '{.access_token}' else: self._tokenKey = tokenKey if not expiryKey: self._expiryKey = '{.token_expiry}' else: self._expiryKey = expiryKey def token(self): fullCmd = self._cmd + (" ") + " ".join(self._args) process = subprocess.Popen( [self._cmd] + self._args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True) (stdout, stderr) = process.communicate() exit_code = process.wait() if exit_code != 0: msg = 'cmd-path: process returned %d' % exit_code msg += "\nCmd: %s" % fullCmd stderr = stderr.strip() if stderr: msg += '\nStderr: %s' % stderr raise ConfigException(msg) try: data = json.loads(stdout) except ValueError as de: raise ConfigException( 'exec: failed to decode process output: %s' % de) A = namedtuple('A', ['token', 'expiry']) return A( token=data['credential']['access_token'], expiry=parse_rfc3339(data['credential']['token_expiry'])) class KubeConfigLoader(object): def __init__(self, config_dict, active_context=None, get_google_credentials=None, config_base_path="", config_persister=None, temp_file_path=None): if config_dict is None: raise ConfigException( 'Invalid kube-config. ' 'Expected config_dict to not be None.') elif isinstance(config_dict, ConfigNode): self._config = config_dict else: 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 self._temp_file_path = temp_file_path def _refresh_credentials_with_cmd_path(): config = self._user['auth-provider']['config'] cmd = config['cmd-path'] if len(cmd) == 0: raise ConfigException( 'missing access token cmd ' '(cmd-path is an empty string in your kubeconfig file)') if 'scopes' in config and config['scopes'] != "": raise ConfigException( 'scopes can only be used ' 'when kubectl is using a gcp service account key') args = [] if 'cmd-args' in config: args = config['cmd-args'].split() else: fields = config['cmd-path'].split() cmd = fields[0] args = fields[1:] commandTokenSource = CommandTokenSource( cmd, args, config.safe_get('token-key'), config.safe_get('expiry-key')) return commandTokenSource.token() def _refresh_credentials(): # Refresh credentials using cmd-path if ('auth-provider' in self._user and 'config' in self._user['auth-provider'] and 'cmd-path' in self._user['auth-provider']['config']): return _refresh_credentials_with_cmd_path() credentials, project_id = google.auth.default(scopes=[ 'https://www.googleapis.com/auth/cloud-platform', 'https://www.googleapis.com/auth/userinfo.email' ]) 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 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. auth-provider (gcp, azure, oidc) 2. token field (point to a token file) 3. exec provided plugin 4. username/password """ if not self._user: return if self._load_auth_provider_token(): return if self._load_user_token(): return if self._load_from_exec_plugin(): return self._load_user_pass_token() def _load_auth_provider_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 self._load_gcp_token(provider) if provider['name'] == 'azure': return self._load_azure_token(provider) if provider['name'] == 'oidc': return self._load_oid_token(provider) def _azure_is_expired(self, provider): expires_on = provider['config']['expires-on'] if expires_on.isdigit(): return int(expires_on) < time.time() else: exp_time = time.strptime(expires_on, '%Y-%m-%d %H:%M:%S.%f') return exp_time < time.gmtime() def _load_azure_token(self, provider): if 'config' not in provider: return if 'access-token' not in provider['config']: return if 'expires-on' in provider['config']: if self._azure_is_expired(provider): self._refresh_azure_token(provider['config']) self.token = 'Bearer %s' % provider['config']['access-token'] return self.token def _refresh_azure_token(self, config): if 'adal' not in globals(): raise ImportError('refresh token error, adal library not imported') tenant = config['tenant-id'] authority = 'https://login.microsoftonline.com/{}'.format(tenant) context = adal.AuthenticationContext( authority, validate_authority=True, api_version='1.0' ) refresh_token = config['refresh-token'] client_id = config['client-id'] apiserver_id = '00000002-0000-0000-c000-000000000000' try: apiserver_id = config['apiserver-id'] except ConfigException: # We've already set a default above pass token_response = context.acquire_token_with_refresh_token( refresh_token, client_id, apiserver_id) provider = self._user['auth-provider']['config'] provider.value['access-token'] = token_response['accessToken'] provider.value['expires-on'] = token_response['expiresOn'] if self._config_persister: self._config_persister() def _load_gcp_token(self, provider): 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'] if 'expiry' in provider['config']: self.expiry = parse_rfc3339(provider['config']['expiry']) 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() def _load_oid_token(self, provider): if 'config' not in provider: return reserved_characters = frozenset(["=", "+", "/"]) token = provider['config']['id-token'] if any(char in token for char in reserved_characters): # Invalid jwt, as it contains url-unsafe chars return parts = token.split('.') if len(parts) != 3: # Not a valid JWT return padding = (4 - len(parts[1]) % 4) * '=' if len(padding) == 3: # According to spec, 3 padding characters cannot occur # in a valid jwt # https://tools.ietf.org/html/rfc7515#appendix-C return if PY3: jwt_attributes = json.loads( base64.urlsafe_b64decode(parts[1] + padding).decode('utf-8') ) else: jwt_attributes = json.loads( base64.b64decode(parts[1] + padding) ) expire = jwt_attributes.get('exp') if ((expire is not None) and (_is_expired(datetime.datetime.fromtimestamp(expire, tz=UTC)))): self._refresh_oidc(provider) if self._config_persister: self._config_persister() self.token = "Bearer %s" % provider['config']['id-token'] return self.token def _refresh_oidc(self, provider): config = Configuration() if 'idp-certificate-authority-data' in provider['config']: ca_cert = tempfile.NamedTemporaryFile(delete=True) if PY3: cert = base64.b64decode( provider['config']['idp-certificate-authority-data'] ).decode('utf-8') else: cert = base64.b64decode( provider['config']['idp-certificate-authority-data'] + "==" ) with open(ca_cert.name, 'w') as fh: fh.write(cert) config.ssl_ca_cert = ca_cert.name elif 'idp-certificate-authority' in provider['config']: config.ssl_ca_cert = provider['config']['idp-certificate-authority'] else: config.verify_ssl = False client = ApiClient(configuration=config) response = client.request( method="GET", url="%s/.well-known/openid-configuration" % provider['config']['idp-issuer-url'] ) if response.status != 200: return response = json.loads(response.data) request = OAuth2Session( client_id=provider['config']['client-id'], token=provider['config']['refresh-token'], auto_refresh_kwargs={ 'client_id': provider['config']['client-id'], 'client_secret': provider['config']['client-secret'] }, auto_refresh_url=response['token_endpoint'] ) try: refresh = request.refresh_token( token_url=response['token_endpoint'], refresh_token=provider['config']['refresh-token'], auth=(provider['config']['client-id'], provider['config']['client-secret']), verify=config.ssl_ca_cert if config.verify_ssl else None ) except oauthlib.oauth2.rfc6749.errors.InvalidClientIdError: return provider['config'].value['id-token'] = refresh['id_token'] provider['config'].value['refresh-token'] = refresh['refresh_token'] def _load_from_exec_plugin(self): if 'exec' not in self._user: return try: base_path = self._get_base_path(self._cluster.path) status = ExecProvider(self._user['exec'], base_path, self._cluster).run() if 'token' in status: self.token = "Bearer %s" % status['token'] elif 'clientCertificateData' in status: # https://kubernetes.io/docs/reference/access-authn-authz/authentication/#input-and-output-formats # Plugin has provided certificates instead of a token. if 'clientKeyData' not in status: logging.error('exec: missing clientKeyData field in ' 'plugin output') return None self.cert_file = FileOrData( status, None, data_key_name='clientCertificateData', file_base_path=base_path, base64_file_content=False, temp_file_path=self._temp_file_path).as_file() self.key_file = FileOrData( status, None, data_key_name='clientKeyData', file_base_path=base_path, base64_file_content=False, temp_file_path=self._temp_file_path).as_file() else: logging.error('exec: missing token or clientCertificateData ' 'field in plugin output') return None if 'expirationTimestamp' in status: self.expiry = parse_rfc3339(status['expirationTimestamp']) return True except Exception as e: logging.error(str(e)) def _load_user_token(self): base_path = self._get_base_path(self._user.path) token = FileOrData( self._user, 'tokenFile', 'token', file_base_path=base_path, base64_file_content=False, temp_file_path=self._temp_file_path).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 _get_base_path(self, config_path): if self._config_base_path is not None: return self._config_base_path if config_path is not None: return os.path.abspath(os.path.dirname(config_path)) return "" def _load_cluster_info(self): if 'server' in self._cluster: self.host = self._cluster['server'].rstrip('/') if self.host.startswith("https"): base_path = self._get_base_path(self._cluster.path) self.ssl_ca_cert = FileOrData( self._cluster, 'certificate-authority', file_base_path=base_path, temp_file_path=self._temp_file_path).as_file() if 'cert_file' not in self.__dict__: # cert_file could have been provided by # _load_from_exec_plugin; only load from the _user # section if we need it. self.cert_file = FileOrData( self._user, 'client-certificate', file_base_path=base_path, temp_file_path=self._temp_file_path).as_file() self.key_file = FileOrData( self._user, 'client-key', file_base_path=base_path, temp_file_path=self._temp_file_path).as_file() if 'insecure-skip-tls-verify' in self._cluster: self.verify_ssl = not self._cluster['insecure-skip-tls-verify'] if 'tls-server-name' in self._cluster: self.tls_server_name = self._cluster['tls-server-name'] def _set_config(self, client_configuration): if 'token' in self.__dict__: client_configuration.api_key['authorization'] = self.token def _refresh_api_key(client_configuration): if ('expiry' in self.__dict__ and _is_expired(self.expiry)): self._load_authentication() self._set_config(client_configuration) client_configuration.refresh_api_key_hook = _refresh_api_key # copy these keys directly from self to configuration object keys = ['host', 'ssl_ca_cert', 'cert_file', 'key_file', 'verify_ssl','tls_server_name'] for key in keys: if key in self.__dict__: setattr(client_configuration, key, getattr(self, key)) def load_and_set(self, client_configuration): self._load_authentication() self._load_cluster_info() self._set_config(client_configuration) 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, path=None): self.name = name self.value = value self.path = path 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 v is None: 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, self.path) 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) result = None 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: if result is None: result = v else: raise ConfigException( 'Invalid kube-config file. ' 'Expected only one object with name %s in %s list' % (name, self.name)) if result is not None: if isinstance(result, ConfigNode): return result else: return ConfigNode( '%s[name=%s]' % (self.name, name), result, self.path) if safe: return None raise ConfigException( 'Invalid kube-config file. ' 'Expected object with name %s in %s list' % (name, self.name)) class KubeConfigMerger: """Reads and merges configuration from one or more kube-config's. The property `config` can be passed to the KubeConfigLoader as config_dict. It uses a path attribute from ConfigNode to store the path to kubeconfig. This path is required to load certs from relative paths. A method `save_changes` updates changed kubeconfig's (it compares current state of dicts with). """ def __init__(self, paths): self.paths = [] self.config_files = {} self.config_merged = None if hasattr(paths, 'read'): self._load_config_from_file_like_object(paths) else: self._load_config_from_file_path(paths) @property def config(self): return self.config_merged def _load_config_from_file_like_object(self, string): if hasattr(string, 'getvalue'): config = yaml.safe_load(string.getvalue()) else: config = yaml.safe_load(string.read()) if config is None: raise ConfigException( 'Invalid kube-config.') if self.config_merged is None: self.config_merged = copy.deepcopy(config) # doesn't need to do any further merging def _load_config_from_file_path(self, string): for path in string.split(ENV_KUBECONFIG_PATH_SEPARATOR): if path: path = os.path.expanduser(path) if os.path.exists(path): self.paths.append(path) self.load_config(path) self.config_saved = copy.deepcopy(self.config_files) def load_config(self, path): with open(path) as f: config = yaml.safe_load(f) if config is None: raise ConfigException( 'Invalid kube-config. ' '%s file is empty' % path) if self.config_merged is None: config_merged = copy.deepcopy(config) for item in ('clusters', 'contexts', 'users'): config_merged[item] = [] self.config_merged = ConfigNode(path, config_merged, path) for item in ('clusters', 'contexts', 'users'): self._merge(item, config.get(item, []) or [], path) if 'current-context' in config: self.config_merged.value['current-context'] = config['current-context'] self.config_files[path] = config def _merge(self, item, add_cfg, path): for new_item in add_cfg: for exists in self.config_merged.value[item]: if exists['name'] == new_item['name']: break else: self.config_merged.value[item].append(ConfigNode( '{}/{}'.format(path, new_item), new_item, path)) def save_changes(self): for path in self.paths: if self.config_saved[path] != self.config_files[path]: self.save_config(path) self.config_saved = copy.deepcopy(self.config_files) def save_config(self, path): with open(path, 'w') as f: yaml.safe_dump(self.config_files[path], f, default_flow_style=False) def _get_kube_config_loader_for_yaml_file( filename, persist_config=False, **kwargs): return _get_kube_config_loader( filename=filename, persist_config=persist_config, **kwargs) def _get_kube_config_loader( filename=None, config_dict=None, persist_config=False, **kwargs): if config_dict is None: kcfg = KubeConfigMerger(filename) if persist_config and 'config_persister' not in kwargs: kwargs['config_persister'] = kcfg.save_changes if kcfg.config is None: raise ConfigException( 'Invalid kube-config file. ' 'No configuration found.') return KubeConfigLoader( config_dict=kcfg.config, config_base_path=None, **kwargs) else: return KubeConfigLoader( config_dict=config_dict, config_base_path=None, **kwargs) def list_kube_config_contexts(config_file=None): if config_file is None: config_file = KUBE_CONFIG_DEFAULT_LOCATION loader = _get_kube_config_loader(filename=config_file) return loader.list_contexts(), loader.current_context def load_kube_config(config_file=None, context=None, client_configuration=None, persist_config=True, temp_file_path=None): """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.Configuration to set configs to. :param persist_config: If True, config file will be updated when changed (e.g GCP token refresh). :param temp_file_path: store temp files path. """ if config_file is None: config_file = KUBE_CONFIG_DEFAULT_LOCATION loader = _get_kube_config_loader( filename=config_file, active_context=context, persist_config=persist_config, temp_file_path=temp_file_path) if client_configuration is None: config = type.__call__(Configuration) loader.load_and_set(config) Configuration.set_default(config) else: loader.load_and_set(client_configuration) def load_kube_config_from_dict(config_dict, context=None, client_configuration=None, persist_config=True, temp_file_path=None): """Loads authentication and cluster information from config_dict file and stores them in kubernetes.client.configuration. :param config_dict: Takes the config file as a dict. :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.Configuration to set configs to. :param persist_config: If True, config file will be updated when changed (e.g GCP token refresh). :param temp_file_path: store temp files path. """ if config_dict is None: raise ConfigException( 'Invalid kube-config dict. ' 'No configuration found.') loader = _get_kube_config_loader( config_dict=config_dict, active_context=context, persist_config=persist_config, temp_file_path=temp_file_path) if client_configuration is None: config = type.__call__(Configuration) loader.load_and_set(config) Configuration.set_default(config) else: loader.load_and_set(client_configuration) def new_client_from_config( config_file=None, context=None, persist_config=True, client_configuration=None): """ 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. """ if client_configuration is None: client_configuration = type.__call__(Configuration) load_kube_config(config_file=config_file, context=context, client_configuration=client_configuration, persist_config=persist_config) return ApiClient(configuration=client_configuration) def new_client_from_config_dict( config_dict=None, context=None, persist_config=True, temp_file_path=None, client_configuration=None): """ Loads configuration the same as load_kube_config_from_dict but returns an ApiClient to be used with any API object. This will allow the caller to concurrently talk with multiple clusters. """ if client_configuration is None: client_configuration = type.__call__(Configuration) load_kube_config_from_dict(config_dict=config_dict, context=context, client_configuration=client_configuration, persist_config=persist_config, temp_file_path=temp_file_path) return ApiClient(configuration=client_configuration)