Use recommended function to setup auth middleware in devstack

Currently Mistral has own configuration for keystone
auth middleware, many parameters of which are deprecated [1].
It's not desired behavior and it is suggested to use recommended
devstack configuration function to prevent possible errors if
something is changed in keystone deployment in the future.

This patch fixes this situation and implements official
"configure_auth_token_middleware" function support.

[1] 712438ebf9/keystonemiddleware/auth_token/_auth.py (L29-L35)

Change-Id: I884777826d6ed40d58f75ec5dfba93a876752dfe
Closes-bug: #1697662

devstack/plugin.sh

@@ -59,6 +59,11 @@ function mkdir_chown_stack {
 
 # configure_mistral - Set config files, create data dirs, etc
 function configure_mistral {
+
+    # create and clean up auth cache dir
+    mkdir_chown_stack "$MISTRAL_AUTH_CACHE_DIR"
+    rm -f "$MISTRAL_AUTH_CACHE_DIR"/*
+
     mkdir_chown_stack "$MISTRAL_CONF_DIR"
 
     # Generate Mistral configuration file and configure common parameters.
@@ -75,14 +80,8 @@ function configure_mistral {
     #-------------------------
 
     # Setup keystone_authtoken section
-    iniset $MISTRAL_CONF_FILE keystone_authtoken auth_host $KEYSTONE_AUTH_HOST
-    iniset $MISTRAL_CONF_FILE keystone_authtoken auth_port $KEYSTONE_AUTH_PORT
-    iniset $MISTRAL_CONF_FILE keystone_authtoken auth_protocol $KEYSTONE_AUTH_PROTOCOL
-    iniset $MISTRAL_CONF_FILE keystone_authtoken admin_tenant_name $SERVICE_TENANT_NAME
-    iniset $MISTRAL_CONF_FILE keystone_authtoken admin_user $MISTRAL_ADMIN_USER
-    iniset $MISTRAL_CONF_FILE keystone_authtoken admin_password $SERVICE_PASSWORD
+    configure_auth_token_middleware $MISTRAL_CONF_FILE mistral $MISTRAL_AUTH_CACHE_DIR
     iniset $MISTRAL_CONF_FILE keystone_authtoken auth_uri $KEYSTONE_AUTH_URI_V3
-    iniset $MISTRAL_CONF_FILE keystone_authtoken identity_uri $KEYSTONE_AUTH_URI
 
     # Setup RabbitMQ credentials
     iniset $MISTRAL_CONF_FILE oslo_messaging_rabbit rabbit_userid $RABBIT_USERID
@@ -250,8 +249,8 @@ if is_service_enabled mistral; then
         install_mistral_pythonclient
     elif [[ "$1" == "stack" && "$2" == "post-config" ]]; then
         echo_summary "Configuring mistral"
-        configure_mistral
         create_mistral_accounts
+        configure_mistral
     elif [[ "$1" == "stack" && "$2" == "extra" ]]; then
         echo_summary "Initializing mistral"
         init_mistral

devstack/settings

@@ -29,6 +29,7 @@ MISTRAL_DASHBOARD_DIR=$DEST/mistral-dashboard
 MISTRAL_CONF_DIR=${MISTRAL_CONF_DIR:-/etc/mistral}
 MISTRAL_CONF_FILE=${MISTRAL_CONF_DIR}/mistral.conf
 MISTRAL_DEBUG=${MISTRAL_DEBUG:-True}
+MISTRAL_AUTH_CACHE_DIR=${MISTRAL_AUTH_CACHE_DIR:-/var/cache/mistral}
 
 MISTRAL_SERVICE_HOST=${MISTRAL_SERVICE_HOST:-$SERVICE_HOST}
 MISTRAL_SERVICE_PORT=${MISTRAL_SERVICE_PORT:-8989}

mistral/services/security.py

@@ -42,8 +42,7 @@ def create_trust():
 
     ctx = auth_ctx.ctx()
 
-    trustee_id = keystone.client_for_admin(
-        CONF.keystone_authtoken.admin_tenant_name).user_id
+    trustee_id = keystone.client_for_admin().session.get_user_id()
 
     return client.trusts.create(
         trustor_user=client.user_id,

mistral/utils/openstack/keystone.py

@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import keystoneauth1.identity.generic as auth_plugins
+from keystoneauth1 import loading
 from keystoneauth1 import session as ks_session
 from keystoneauth1.token_endpoint import Token
 from keystoneclient import service_catalog as ks_service_catalog
@@ -27,6 +27,7 @@ from mistral import context
 from mistral import exceptions
 
 CONF = cfg.CONF
+CONF.register_opt(cfg.IntOpt('timeout'), group='keystone_authtoken')
 
 
 def client():
@@ -92,23 +93,32 @@ def get_session_and_auth(context, **kwargs):
 
 
 def _admin_client(trust_id=None, project_name=None):
-    auth_url = CONF.keystone_authtoken.auth_uri
+    kwargs = {}
 
-    cl = ks_client.Client(
-        username=CONF.keystone_authtoken.admin_user,
-        password=CONF.keystone_authtoken.admin_password,
-        project_name=project_name,
-        auth_url=auth_url,
-        trust_id=trust_id
+    if trust_id:
+        # Remove project_name and project_id, since we need a trust scoped
+        # auth object
+        kwargs['project_name'] = None
+        kwargs['project_domain_name'] = None
+        kwargs['project_id'] = None
+        kwargs['trust_id'] = trust_id
+
+    auth = loading.load_auth_from_conf_options(
+        CONF,
+        'keystone_authtoken',
+        **kwargs
+    )
+    sess = loading.load_session_from_conf_options(
+        CONF,
+        'keystone_authtoken',
+        auth=auth
     )
 
-    cl.management_url = auth_url
-
-    return cl
+    return ks_client.Client(session=sess)
 
 
-def client_for_admin(project_name):
-    return _admin_client(project_name=project_name)
+def client_for_admin():
+    return _admin_client()
 
 
 def client_for_trusts(trust_id):
@@ -230,28 +240,21 @@ def format_url(url_template, values):
 
 
 def is_token_trust_scoped(auth_token):
-    admin_project_name = CONF.keystone_authtoken.admin_tenant_name
-    keystone_client = _admin_client(project_name=admin_project_name)
-
-    token_info = keystone_client.tokens.validate(auth_token)
-
-    return 'OS-TRUST:trust' in token_info
+    return 'OS-TRUST:trust' in client_for_admin().tokens.validate(auth_token)
 
 
 def get_admin_session():
     """Returns a keystone session from Mistral's service credentials."""
+    auth = loading.load_auth_from_conf_options(
+        CONF,
+        'keystone_authtoken'
+    )
 
-    auth = auth_plugins.Password(
-        CONF.keystone_authtoken.auth_uri,
-        username=CONF.keystone_authtoken.admin_user,
-        password=CONF.keystone_authtoken.admin_password,
-        project_name=CONF.keystone_authtoken.admin_tenant_name,
-        # NOTE(jaosorior): Once mistral supports keystone v3 properly, we can
-        # fetch the following values from the configuration.
-        user_domain_name='Default',
-        project_domain_name='Default')
-
-    return ks_session.Session(auth=auth)
+    return loading.load_session_from_conf_options(
+        CONF,
+        'keystone_authtoken',
+        auth=auth
+    )
 
 
 def will_expire_soon(expires_at):