Add kube config support

.swagger-codegen-ignore

@@ -1,3 +1,5 @@
 .gitignore
 git_push.sh
 test/*
+requirements.txt
+setup.py

k8sutil/__init__.py

@@ -0,0 +1,15 @@
+# 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.
+
+from .kube_config import load_kube_config

k8sutil/kube_config.py

@@ -0,0 +1,172 @@
+# 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 os
+import tempfile
+
+import urllib3
+import yaml
+from k8sclient import configuration
+from oauth2client.client import GoogleCredentials
+
+_temp_files = []
+
+
+def _cleanup_temp_files():
+    for f in _temp_files:
+        os.remove(f)
+
+
+def _create_temp_file_with_content(content):
+    if len(_temp_files) == 0:
+        atexit.register(_cleanup_temp_files)
+    _, name = tempfile.mkstemp()
+    _temp_files.append(name)
+    if isinstance(content, str):
+        content = content.encode('utf8')
+    with open(name, 'wb') as fd:
+        fd.write(base64.decodestring(content))
+    return name
+
+
+def _file_from_file_or_data(o, file_key_name, data_key_name=None):
+    if not data_key_name:
+        data_key_name = file_key_name + "-data"
+    if data_key_name in o:
+        return _create_temp_file_with_content(o[data_key_name])
+    if file_key_name in o:
+        return o[file_key_name]
+
+
+def _data_from_file_or_data(o, file_key_name, data_key_name=None):
+    if not data_key_name:
+        data_key_name = file_key_name + "_data"
+    if data_key_name in o:
+        return o[data_key_name]
+    if file_key_name in o:
+        with open(o[file_key_name], 'r') as f:
+            data = f.read()
+        return data
+
+
+def _load_gcp_token(user):
+    if 'auth-provider' not in user:
+        return
+    if 'name' not in user['auth-provider']:
+        return
+    if user['auth-provider']['name'] != 'gcp':
+        return
+    # Ignore configs in auth-provider and rely on GoogleCredentials
+    # caching and refresh mechanism.
+    # TODO: support gcp command based token ("cmd-path" config).
+    return (GoogleCredentials
+            .get_application_default()
+            .get_access_token()
+            .access_token)
+
+
+def _load_authentication(user):
+    """Read authentication from kube-config user section.
+
+    This function goes through various authetication methods in user section of
+    kubeconfig and stops if it founds 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
+    """
+    # Read authentication
+    token = _load_gcp_token(user)
+    if not token:
+        token = _data_from_file_or_data(user, 'tokenFile', 'token')
+    if token:
+        configuration.api_key['authorization'] = "bearer " + token
+    else:
+        if 'username' in user and 'password' in user:
+            configuration.api_key['authorization'] = urllib3.util.make_headers(
+                basic_auth=user['username'] + ':' +
+                user['password']).get('authorization')
+
+
+def _load_cluster_info(cluster, user):
+    """Loads cluster information from kubeconfig such as host and SSL certs."""
+    if 'server' in cluster:
+        configuration.host = cluster['server']
+        if configuration.host.startswith("https"):
+            configuration.ssl_ca_cert = _file_from_file_or_data(
+                cluster, 'certificate-authority')
+            configuration.cert_file = _file_from_file_or_data(
+                user, 'client-certificate')
+            configuration.key_file = _file_from_file_or_data(
+                user, 'client-key')
+
+
+class _node:
+    """Remembers each key's path and construct a relevant exception message
+    in case of missing keys."""
+
+    def __init__(self, name, value):
+        self._name = name
+        self._value = value
+
+    def __contains__(self, key):
+        return key in self._value
+
+    def __getitem__(self, key):
+        if key in self._value:
+            v = self._value[key]
+            if isinstance(v, dict) or isinstance(v, list):
+                return _node('%s/%s' % (self._name, key), v)
+            else:
+                return v
+        raise Exception(
+            'Invalid kube-config file. Expected key %s in %s'
+            % (key, self._name))
+
+    def get_with_name(self, name):
+        if not isinstance(self._value, list):
+            raise Exception(
+                'Invalid kube-config file. Expected %s to be a list'
+                % self._name)
+        for v in self._value:
+            if 'name' not in v:
+                raise Exception(
+                    'Invalid kube-config file. '
+                    'Expected all values in %s list to have \'name\' key'
+                    % self._name)
+            if v['name'] == name:
+                return _node('%s[name=%s]' % (self._name, name), v)
+        raise Exception(
+            "Cannot find object with name %s in %s list" % (name, self._name))
+
+
+def load_kube_config(config_file):
+    """Loads authentication and cluster information from kube-config file
+    and store them in k8sclient.configuration."""
+
+    with open(config_file) as f:
+        config = _node('kube-config', yaml.load(f))
+
+        current_context = config['contexts'].get_with_name(
+            config['current-context'])['context']
+        user = config['users'].get_with_name(current_context['user'])['user']
+        cluster = config['clusters'].get_with_name(
+            current_context['cluster'])['cluster']
+
+        _load_cluster_info(cluster, user)
+        _load_authentication(user)

requirements.txt

@@ -3,3 +3,6 @@ six == 1.8.0
 python_dateutil >= 2.5.3
 setuptools >= 21.0.0
 urllib3 >= 1.15.1
+pyyaml >= 3.12
+oauth2client >= 4.0.0
+

setup.py

@@ -35,7 +35,7 @@
 # prerequisite: setuptools
 # http://pypi.python.org/pypi/setuptools
 
-REQUIRES = ["urllib3 >= 1.15", "six >= 1.10", "certifi", "python-dateutil"]
+REQUIRES = ["urllib3 >= 1.15", "six >= 1.10", "certifi", "python-dateutil", "pyyaml", "oauth2client"]
 
 setup(
     name=NAME,