[fedora-atomic][k8s] Support default Keystone auth policy file

With the new config option `keystone_auth_default_policy`, cloud admin can set a default keystone auth policy for k8s cluster when the keystone auth is enabled. As a result, user can use their current keystone user to access k8s cluster as long as they're assigned correct roles, and they will get the pre-defined permissions set by the cloud provider. The default policy now is based on the v2 format recently introduced in k8s-keystone-auth which is getting more useful now. For example, in v1 it doesn't support a policy for user to access resources from all namespaces but kube-system, but v2 can do that. NOTE: Now we're using openstackmagnum dockerhub repo until CPO team fixing their image release issue. Task: 30069 Story: 1755770 Change-Id: I2425e957bd99edc92482b6f11ca0b1f91fe59ff6
2019-03-14 16:49:37 +13:00 · 2019-03-14 16:49:37 +13:00 · d8df9d0c36
commit d8df9d0c36
parent 05c27f2d73
12 changed files with 349 additions and 24 deletions
--- a/devstack/lib/magnum
+++ b/devstack/lib/magnum
@ -46,6 +46,7 @@ MAGNUM_CERTIFICATE_CACHE_DIR=${MAGNUM_CERTIFICATE_CACHE_DIR:-/var/lib/magnum/cer
 MAGNUM_CONF_DIR=/etc/magnum
 MAGNUM_CONF=$MAGNUM_CONF_DIR/magnum.conf
 MAGNUM_API_PASTE=$MAGNUM_CONF_DIR/api-paste.ini
+MAGNUM_K8S_KEYSTONE_AUTH_DEFAULT_POLICY=$MAGNUM_CONF_DIR/k8s_keystone_auth_default_policy.json
 MAGNUM_POLICY=$MAGNUM_CONF_DIR/policy.yaml

 if is_ssl_enabled_service "magnum" || is_service_enabled tls-proxy; then
@ -98,6 +99,8 @@ function configure_magnum {
    create_magnum_conf

    create_api_paste_conf
+
+    create_k8s_keystone_auth_default_poliy
 }

 # create_magnum_accounts() - Set up common required magnum accounts
@ -117,6 +120,10 @@ function create_magnum_accounts {
        "$MAGNUM_SERVICE_PROTOCOL://$MAGNUM_SERVICE_HOST:$MAGNUM_SERVICE_PORT/v1" \
        "$MAGNUM_SERVICE_PROTOCOL://$MAGNUM_SERVICE_HOST:$MAGNUM_SERVICE_PORT/v1"

+    # Create for Kubernetes Keystone auth
+    get_or_create_role k8s_admin
+    get_or_create_role k8s_developer
+    get_or_create_role k8s_viewer
 }

 # create_magnum_conf() - Create a new magnum.conf file
@ -224,6 +231,8 @@ function create_magnum_conf {
    default_volume_type=$(iniget /etc/cinder/cinder.conf DEFAULT default_volume_type)
    iniset $MAGNUM_CONF cinder default_docker_volume_type $default_volume_type
    iniset $MAGNUM_CONF drivers send_cluster_metrics False
+
+    iniset $MAGNUM_CONF kubernetes keystone_auth_default_policy $MAGNUM_K8S_KEYSTONE_AUTH_DEFAULT_POLICY
 }

 function create_api_paste_conf {
@ -231,6 +240,10 @@ function create_api_paste_conf {
    cp $MAGNUM_DIR/etc/magnum/api-paste.ini $MAGNUM_API_PASTE
 }

+function create_k8s_keystone_auth_default_poliy {
+    cp $MAGNUM_DIR/etc/magnum/keystone_auth_default_policy.sample $MAGNUM_K8S_KEYSTONE_AUTH_DEFAULT_POLICY
+}
+
 # create_magnum_cache_dir() - Part of the init_magnum() process
 function create_magnum_cache_dir {
    # Create cache dir
--- a/doc/source/user/index.rst
+++ b/doc/source/user/index.rst
@ -34,6 +34,7 @@ created and managed by Magnum to support the COE's.
 #. `Container Monitoring`_
 #. `Kubernetes External Load Balancer`_
 #. `Rolling Upgrade`_
+#. `Keystone Authentication and Authorization for Kubernetes`_

 Overview
 ========
@ -3236,3 +3237,9 @@ Rolling Upgrade
 ===============

 .. include:: rolling-upgrade.rst
+=======
+
+Keystone Authentication and Authorization for Kubernetes
+========================================================
+
+.. include:: k8s-keystone-authN-authZ.rst
--- a/doc/source/user/k8s-keystone-authN-authZ.rst
+++ b/doc/source/user/k8s-keystone-authN-authZ.rst
@ -0,0 +1,145 @@
+Currently, there are several ways to access the Kubernetes API, such as RBAC,
+ABAC, Webhook, etc. Though RBAC is the best way for most of the cases, Webhook
+provides a good approach for Kubernetes to query an outside REST service when
+determining user privileges. In other words, we can use a Webhook to integrate
+other IAM service into Kubernetes. In our case, under the OpenStack context,
+we're introducing the intergration with Keystone auth for Kubernetes.
+
+Since Rocky release, we introduced a new label named `keystone_auth_enabled`,
+by default it's True, which means user can get this very nice feature out of
+box.
+
+Create roles
+------------
+
+As cloud provider, necessary Keystone roles for Kubernetes cluster operations
+need to be created for different users, e.g. k8s_admin, k8s_developer,
+k8s_viewer
+
+- k8s_admin role can create/update/delete Kubernetes cluster, can also
+  associate roles to other normal users within the tenant
+- k8s_developer can create/update/delete/watch Kubernetes cluster resources
+- k8s_viewer can only have read access to Kubernetes cluster resources
+
+NOTE: Those roles will be created automatically in devstack. Below is the
+samples commands about how to create them.
+
+.. code-block:: bash
+
+  source ~/openstack_admin_credentials
+  for role in "k8s_admin" "k8s_developer" "k8s_viewer"; do openstack role create $role; done
+
+  openstack user create demo_viewer --project demo --password password
+  openstack role add --user demo_viewer --project demo k8s_viewer
+
+  openstack user create demo_editor --project demo --password password
+  openstack role add --user demo_developer --project demo k8s_developer
+
+  openstack user create demo_admin --project demo --password password
+  openstack role add --user demo_admin --project demo k8s_admin
+
+Those roles should be public and can be accessed by any project so that user
+can configure their cluster's role policies with those roles.
+
+Setup configmap for authorization policies
+------------------------------------------
+
+Given the k8s Keystone auth has been enable by default, user can get the
+authentication support by default without doing anything. However, user can't
+do anything actually before setup a default authorization policies.
+
+The authorization policy can be specified using an existing configmap name in
+the cluster, by doing this, the policy could be changed dynamically without
+the k8s-keystone-auth service restart.
+
+Or the policy can be read from a default policy file. In devstack, the policy
+file will be created automatically.
+
+Currently, k8s-keystone-auth service supports four types of policies:
+
+- user. The Keystone user ID or name.
+- roject. The Keystone project ID or name.
+- role. The user role defined in Keystone.
+- group. The group is not a Keystone concept actually, it’s supported for
+  backward compatibility, you can use group as project ID.
+
+For example, in the following configmap, we only allow the users in
+project demo with k8s-viewer role in OpenStack to query the pod information
+from all the namespaces. So we need to update the configmap
+`k8s-keystone-auth-policy` which has been created in kube-system namespace.
+
+.. code-block:: bash
+
+    cat <<EOF | kubectl apply -f -
+    apiVersion: v1
+    kind: ConfigMap
+    metadata:
+    name: k8s-keystone-auth-policy
+    namespace: kube-system
+    data:
+    policies: |
+        [
+        {
+            "resource": {
+            "verbs": ["get", "list", "watch"],
+            "resources": ["pods"],
+            "version": "*",
+            "namespace": "default"
+            },
+            "match": [
+            {
+                "type": "role",
+                "values": ["k8s-viewer"]
+            },
+            {
+                "type": "project",
+                "values": ["demo"]
+            }
+            ]
+        }
+        ]
+    EOF
+
+Please note that the default configmap name is `k8s-keystone-auth-policy`, user
+can change it, but they have to change the config of the k8s keystone auth
+service configuration as well and restart the service.
+
+Now user need to get a token from Keystone to have a kubeconfig for kubectl,
+user can also get the config with Magnum python client.
+
+Here is a sample of the kubeconfig:
+
+.. code-block:: bash
+
+    apiVersion: v1
+    clusters:
+    - cluster:
+        certificate-authority-data: CERT-DATA==
+        server: https://172.24.4.25:6443
+    name: k8s-2
+    contexts:
+    - context:
+        cluster: k8s-2
+        user: openstackuser
+    name: openstackuser@kubernetes
+    current-context: openstackuser@kubernetes
+    kind: Config
+    preferences: {}
+    users:
+    - name: openstackuser
+    user:
+        exec:
+        command: /bin/bash
+        apiVersion: client.authentication.k8s.io/v1alpha1
+        args:
+        - -c
+        - >
+            if [ -z ${OS_TOKEN} ]; then
+                echo 'Error: Missing OpenStack credential from environment variable $OS_TOKEN' > /dev/stderr
+                exit 1
+            else
+                echo '{ "apiVersion": "client.authentication.k8s.io/v1alpha1", "kind": "ExecCredential", "status": { "token": "'"${OS_TOKEN}"'"}}'
+            fi
+
+Now after export the Keystone token to OS_TOKEN, user should be able to list
+pods with kubectl.
--- a/etc/magnum/keystone_auth_default_policy.sample
+++ b/etc/magnum/keystone_auth_default_policy.sample
@ -0,0 +1,76 @@
+[
+   {
+      "users":{
+         "roles":[
+            "k8s_admin"
+         ],
+         "projects":[
+            "$PROJECT_ID"
+         ]
+      },
+      "resource_permissions":{
+         "*/*":[
+            "*"
+         ]
+      },
+      "nonresource_permissions":{
+         "/healthz":[
+            "get",
+            "post"
+         ]
+      }
+   },
+   {
+      "users":{
+         "roles":[
+            "k8s_developer"
+         ],
+         "projects":[
+            "$PROJECT_ID"
+         ]
+      },
+      "resource_permissions":{
+         "!kube-system/['apiServices', 'bindings', 'componentstatuses', 'configmaps', 'cronjobs', 'customResourceDefinitions', 'deployments', 'endpoints', 'events', 'horizontalPodAutoscalers', 'ingresses', 'initializerConfigurations', 'jobs', 'limitRanges', 'localSubjectAccessReviews', 'namespaces', 'networkPolicies', 'persistentVolumeClaims', 'persistentVolumes', 'podDisruptionBudgets', 'podPresets', 'podTemplates', 'pods', 'replicaSets', 'replicationControllers', 'resourceQuotas', 'secrets', 'selfSubjectAccessReviews', 'serviceAccounts', 'services', 'statefulSets', 'storageClasses', 'subjectAccessReviews', 'tokenReviews']":[
+            "*"
+         ],
+         "*/['clusterrolebindings', 'clusterroles', 'rolebindings', 'roles', 'controllerrevisions', 'nodes', 'podSecurityPolicies']":[
+            "get",
+            "list",
+            "watch"
+         ],
+         "*/['certificateSigningRequests']":[
+            "create",
+            "delete",
+            "get",
+            "list",
+            "watch",
+            "update"
+         ]
+      }
+   },
+   {
+      "users":{
+         "roles":[
+            "k8s_viewer"
+         ],
+         "projects":[
+            "$PROJECT_ID"
+         ]
+      },
+      "resource_permissions":{
+         "!kube-system/['tokenReviews']":[
+            "*"
+         ],
+         "!kube-system/['apiServices', 'bindings', 'componentstatuses', 'configmaps', 'cronjobs', 'customResourceDefinitions', 'deployments', 'endpoints', 'events', 'horizontalPodAutoscalers', 'ingresses', 'initializerConfigurations', 'jobs', 'limitRanges', 'localSubjectAccessReviews', 'namespaces', 'networkPolicies', 'persistentVolumeClaims', 'persistentVolumes', 'podDisruptionBudgets', 'podPresets', 'podTemplates', 'pods', 'replicaSets', 'replicationControllers', 'resourceQuotas', 'secrets', 'selfSubjectAccessReviews', 'serviceAccounts', 'services', 'statefulSets', 'storageClasses', 'subjectAccessReviews']":[
+            "get",
+            "list",
+            "watch"
+         ],
+         "*/['clusterrolebindings', 'clusterroles', 'rolebindings', 'roles', 'controllerrevisions', 'nodes', 'podSecurityPolicies']":[
+            "get",
+            "list",
+            "watch"
+         ]
+      }
+   }
+]
--- a/magnum/conf/init.py
+++ b/magnum/conf/init.py
@ -30,6 +30,7 @@ from magnum.conf import drivers
 from magnum.conf import glance
 from magnum.conf import heat
 from magnum.conf import keystone
+from magnum.conf import kubernetes
 from magnum.conf import magnum_client
 from magnum.conf import neutron
 from magnum.conf import nova
@ -60,6 +61,7 @@ drivers.register_opts(CONF)
 glance.register_opts(CONF)
 heat.register_opts(CONF)
 keystone.register_opts(CONF)
+kubernetes.register_opts(CONF)
 magnum_client.register_opts(CONF)
 neutron.register_opts(CONF)
 nova.register_opts(CONF)
--- a/magnum/conf/kubernetes.py
+++ b/magnum/conf/kubernetes.py
@ -0,0 +1,36 @@
+# 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 oslo_config import cfg
+
+kubernetes_group = cfg.OptGroup(name='kubernetes',
+                                title='Options for the Kubernetes addons')
+
+kubernetes_opts = [
+    cfg.StrOpt('keystone_auth_default_policy',
+               default="/etc/magnum/keystone_auth_default_policy.json",
+               help='Explicitly specify the path to the file defined default '
+                    'Keystone auth policy for Kubernetes cluster when '
+                    'the Keystone auth is enabled. Vendors can put their '
+                    'specific default policy here'),
+]
+
+
+def register_opts(conf):
+    conf.register_group(kubernetes_group)
+    conf.register_opts(kubernetes_opts, group=kubernetes_group)
+
+
+def list_opts():
+    return {
+        kubernetes_group: kubernetes_opts
+    }
--- a/magnum/drivers/common/templates/kubernetes/fragments/enable-keystone-auth.sh
+++ b/magnum/drivers/common/templates/kubernetes/fragments/enable-keystone-auth.sh
@ -6,7 +6,7 @@ step="enable-keystone-auth"
 printf "Starting to run ${step}\n"

 if [ "$(echo $KEYSTONE_AUTH_ENABLED | tr '[:upper:]' '[:lower:]')" != "false" ]; then
-    _prefix=${CONTAINER_INFRA_PREFIX:-docker.io/k8scloudprovider/}
+    _prefix=${CONTAINER_INFRA_PREFIX:-docker.io/openstackmagnum/}
    CERT_DIR=/etc/kubernetes/certs

    # Create policy configmap for keystone auth
@ -65,26 +65,7 @@ metadata:
  namespace: kube-system
 data:
  policies: |
-    [
-      {
-        "resource": {
-          "verbs": ["list"],
-          "resources": ["pods", "services", "deployments", "pvc"],
-          "version": "*",
-          "namespace": "default"
-        },
-        "match": [
-          {
-            "type": "role",
-            "values": ["member"]
-          },
-          {
-            "type": "project",
-            "values": ["$PROJECT_ID"]
-          }
-        ]
-      }
-    ]
+    $KEYSTONE_AUTH_DEFAULT_POLICY
 EOF
    }

@ -182,4 +163,4 @@ EOF

 fi

-printf "Finished running ${step}\n"
+printf "Finished running ${step}\n"
--- a/magnum/drivers/heat/k8s_fedora_template_def.py
+++ b/magnum/drivers/heat/k8s_fedora_template_def.py
@ -10,6 +10,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.

+import json
+
 from oslo_log import log as logging
 from oslo_utils import strutils

@ -158,6 +160,7 @@ class K8sFedoraTemplateDefinition(k8s_template_def.K8sTemplateDefinition):
            extra_params['max_node_count'] = cluster.node_count + 1

        self._set_cert_manager_params(cluster, extra_params)
+        self._get_keystone_auth_default_policy(extra_params)

        return super(K8sFedoraTemplateDefinition,
                     self).get_params(context, cluster_template, cluster,
@ -180,6 +183,35 @@ class K8sFedoraTemplateDefinition(k8s_template_def.K8sTemplateDefinition):
                    ca_cert.get_private_key(),
                    ca_cert.get_private_key_passphrase()).replace("\n", "\\n")

+    def _get_keystone_auth_default_policy(self, extra_params):
+        # NOTE(flwang): This purpose of this function is to make the default
+        # policy more flexible for different cloud providers. Since the default
+        # policy was "hardcode" in the bash script and vendors can't change
+        # it unless fork it. So the new config option is introduced to address
+        # this. This function can be extracted to k8s_template_def.py if k8s
+        # keystone auth feature is adopted by other drivers.
+
+        default_policy = """[{"resource": {"verbs": ["list"],
+            "resources": ["pods", "services", "deployments", "pvc"],
+            "version": "*", "namespace": "default"},
+            "match": [{"type": "role","values": ["member"]},
+            {"type": "project", "values": ["$PROJECT_ID"]}]}]"""
+
+        keystone_auth_enabled = extra_params.get("keystone_auth_enabled",
+                                                 "True")
+        if strutils.bool_from_string(keystone_auth_enabled):
+            try:
+                with open(CONF.kubernetes.keystone_auth_default_policy) as f:
+                    default_policy = json.dumps(json.loads(f.read()))
+            except Exception:
+                LOG.error("Failed to load default keystone auth policy")
+                default_policy = json.dumps(json.loads(default_policy),
+                                            sort_keys=True)
+
+            washed_policy = default_policy.replace('"', '\"') \
+                .replace("$PROJECT_ID", extra_params["project_id"])
+            extra_params["keystone_auth_default_policy"] = washed_policy
+
    def get_env_files(self, cluster_template, cluster):
        env_files = []

--- a/magnum/drivers/k8s_fedora_atomic_v1/templates/kubecluster.yaml
+++ b/magnum/drivers/k8s_fedora_atomic_v1/templates/kubecluster.yaml
@ -563,10 +563,14 @@ parameters:
    default:
      true

+  keystone_auth_default_policy:
+    type: string
+    description: Json read from /etc/magnum/keystone_auth_default_policy.json
+
  k8s_keystone_auth_tag:
    type: string
    description: tag of the k8s_keystone_auth container
-    default: 1.13.0
+    default: v1.14.0

  monitoring_enabled:
    type: boolean
@ -965,7 +969,10 @@ resources:
                  $enable-ingress-octavia: {get_file: ../../common/templates/kubernetes/fragments/enable-ingress-octavia.sh}
                template: {get_file: ../../common/templates/kubernetes/fragments/enable-ingress-controller.sh}
            - get_file: ../../common/templates/kubernetes/fragments/kube-dashboard-service.sh
-            - get_file: ../../common/templates/kubernetes/fragments/enable-keystone-auth.sh
+            - str_replace:
+                template: {get_file: ../../common/templates/kubernetes/fragments/enable-keystone-auth.sh}
+                params:
+                  "$KEYSTONE_AUTH_DEFAULT_POLICY": {get_param: keystone_auth_default_policy}
            - get_file: ../../common/templates/kubernetes/fragments/enable-auto-healing.sh
            - get_file: ../../common/templates/kubernetes/fragments/enable-auto-scaling.sh
            # Helm Based Installation Configuration Scripts
--- a/magnum/tests/unit/conductor/handlers/test_k8s_cluster_conductor.py
+++ b/magnum/tests/unit/conductor/handlers/test_k8s_cluster_conductor.py
@ -27,6 +27,15 @@ CONF = magnum.conf.CONF
 class TestClusterConductorWithK8s(base.TestCase):
    def setUp(self):
        super(TestClusterConductorWithK8s, self).setUp()
+        self.keystone_auth_default_policy = ('[{"match": [{"type": "role", '
+                                             '"values": ["member"]}, {"type": '
+                                             '"project", "values": '
+                                             '["project_id"]}], "resource": '
+                                             '{"namespace": "default", '
+                                             '"resources": ["pods", '
+                                             '"services", "deployments", '
+                                             '"pvc"], "verbs": ["list"], '
+                                             '"version": "*"}}]')
        self.cluster_template_dict = {
            'image_id': 'image_id',
            'flavor_id': 'flavor_id',
@ -109,6 +118,7 @@ class TestClusterConductorWithK8s(base.TestCase):
            'master_flavor_id': 'master_flavor_id',
            'flavor_id': 'flavor_id',
            'project_id': 'project_id',
+            'keystone_auth_default_policy': self.keystone_auth_default_policy
        }
        self.worker_ng_dict = {
            'uuid': '5d12f6fd-a196-4bf0-ae4c-1f639a523a53',
@ -335,6 +345,7 @@ class TestClusterConductorWithK8s(base.TestCase):
            'max_node_count': 2,
            'master_image': 'image_id',
            'minion_image': 'image_id',
+            'keystone_auth_default_policy': self.keystone_auth_default_policy
        }
        if missing_attr is not None:
            expected.pop(mapping[missing_attr], None)
@ -473,6 +484,7 @@ class TestClusterConductorWithK8s(base.TestCase):
            'max_node_count': 2,
            'master_image': 'image_id',
            'minion_image': 'image_id',
+            'keystone_auth_default_policy': self.keystone_auth_default_policy
        }

        self.assertEqual(expected, definition)
@ -591,6 +603,7 @@ class TestClusterConductorWithK8s(base.TestCase):
            'max_node_count': 2,
            'master_image': None,
            'minion_image': None,
+            'keystone_auth_default_policy': self.keystone_auth_default_policy
        }
        self.assertEqual(expected, definition)
        self.assertEqual(
@ -1020,6 +1033,7 @@ class TestClusterConductorWithK8s(base.TestCase):
            'max_node_count': 2,
            'master_image': 'image_id',
            'minion_image': 'image_id',
+            'keystone_auth_default_policy': self.keystone_auth_default_policy
        }
        self.assertEqual(expected, definition)
        self.assertEqual(
--- a/magnum/tests/unit/drivers/test_template_definition.py
+++ b/magnum/tests/unit/drivers/test_template_definition.py
@ -661,6 +661,7 @@ class AtomicK8sTemplateDefinitionTestCase(BaseK8sTemplateDefinitionTestCase):
        mock_cluster = mock.MagicMock()
        mock_cluster.labels = {}
        mock_cluster.uuid = '5d12f6fd-a196-4bf0-ae4c-1f639a523a52'
+        mock_cluster.project_id = 'e2a6c8b0-a3c2-42a3-b3f4-1f639a523a52'

        mock_osc = mock.MagicMock()
        mock_osc.magnum_url.return_value = 'http://127.0.0.1:9511/v1'
@ -717,6 +718,7 @@ class AtomicK8sTemplateDefinitionTestCase(BaseK8sTemplateDefinitionTestCase):
        mock_cluster = mock.MagicMock()
        mock_cluster.labels = {"ingress_controller": "octavia"}
        mock_cluster.uuid = '5d12f6fd-a196-4bf0-ae4c-1f639a523a52'
+        mock_cluster.project_id = 'e2a6c8b0-a3c2-42a3-b3f4-1f639a523a52'

        mock_osc = mock.MagicMock()
        mock_osc.magnum_url.return_value = 'http://127.0.0.1:9511/v1'
@ -770,6 +772,7 @@ class AtomicK8sTemplateDefinitionTestCase(BaseK8sTemplateDefinitionTestCase):
        mock_cluster = mock.MagicMock()
        mock_cluster.labels = {"ingress_controller": "octavia"}
        mock_cluster.uuid = '5d12f6fd-a196-4bf0-ae4c-1f639a523a52'
+        mock_cluster.project_id = 'e2a6c8b0-a3c2-42a3-b3f4-1f639a523a52'

        mock_osc = mock.MagicMock()
        mock_osc.magnum_url.return_value = 'http://127.0.0.1:9511/v1'
--- a/releasenotes/notes/default-policy-k8s-keystone-auth-fa74aa03dcc12ef3.yaml
+++ b/releasenotes/notes/default-policy-k8s-keystone-auth-fa74aa03dcc12ef3.yaml
@ -0,0 +1,9 @@
+---
+issues:
+  - |
+    With the new config option keystone_auth_default_policy, cloud admin
+    can set a default keystone auth policy for k8s cluster when the
+    keystone auth is enabled. As a result, user can use their current
+    keystone user to access k8s cluster as long as they're assigned
+    correct roles, and they will get the pre-defined permissions
+    defined by the cloud provider.