Add support for websso-fid-service-provider relation.

This change adds support to relate the keystone-openidc charm to
openstack-dashboard allowing it expose a OpenID Connect backend for
logging into Horizon.

The configuration option 'user-facing-name' allows operator to set a
user friendly name that gets displayed in the list of choices available
for logging in.

Change-Id: Ia09cb5b68bc35d25f5b012f0011697966827eb03

config.yaml

@@ -108,3 +108,9 @@ options:
       OAuth 2.0 Authorization Server token introspection endpoint. When
       `enable-oauth` is set to true and this option unset (the default), the
       introspection endpoint available in the metadata will be used.
+  user-facing-name:
+    type: string
+    default: 'OpenID Connect via mapped'
+    description: |
+      A user-facing name to be used for the identity provider and protocol
+      combination. Used in the OpenStack dashboard.

src/charm.py

@@ -91,12 +91,12 @@ class KeystoneOpenIDCOptions(ConfigurationAdapter):
 
     @property
     def oidc_auth_path(self) -> str:
-        service_name = self.charm_instance.unit.app.name
-        return (f'/v3/OS-FEDERATION/identity_providers/{service_name}'
+        return (f'/v3/OS-FEDERATION/identity_providers/{self.idp_id}'
                 f'/protocols/openid/auth')
 
     @property
     def idp_id(self) -> str:
+        """Identity provider name to use for URL generation."""
         return 'openid'
 
     @property
@@ -215,10 +215,6 @@ class KeystoneOpenIDCCharm(ops_openstack.core.OSBaseCharm):
         )
 
         # websso-fid-service-provider
-        self.framework.observe(
-            self.on.websso_fid_service_provider_relation_joined,
-            self._on_websso_fid_service_provider_relation_joined
-        )
         self.framework.observe(
             self.on.websso_fid_service_provider_relation_changed,
             self._on_websso_fid_service_provider_relation_changed
@@ -269,14 +265,27 @@ class KeystoneOpenIDCCharm(ops_openstack.core.OSBaseCharm):
         data['remote-id-attribute'] = json.dumps(
             self.options.remote_id_attribute)
 
-    def _on_websso_fid_service_provider_relation_joined(self, event):
-        pass
-
     def _on_websso_fid_service_provider_relation_changed(self, event):
-        pass
+        self._update_websso_data()
 
     def _update_websso_data(self):
-        pass
+        """Update websso-fid-service-provider relation data.
+
+        When there is a relation established via websso-fid-service-provider
+        this handler will take care of update the relation data with the
+        information that openstack-dashboard expects to enable WebSSO
+        Federation.
+        """
+        relation = self.model.get_relation('websso-fid-service-provider')
+        if not relation:
+            logger.debug('There is not relation established via '
+                         'websso-fid-service-provider interface')
+            return
+
+        data = relation.data[self.unit]
+        data['protocol-name'] = json.dumps(self.options.idp_id)
+        data['idp-name'] = json.dumps(self.options.protocol_id)
+        data['user-facing-name'] = json.dumps(self.options.user_facing_name)
 
     def _on_config_changed(self, event):
         if not self.is_data_ready():
@@ -289,6 +298,7 @@ class KeystoneOpenIDCCharm(ops_openstack.core.OSBaseCharm):
         self._stored.is_started = True
         self.update_config_if_needed()
         self.update_principal_data()
+        self._update_websso_data()
 
     def update_config_if_needed(self):
         with ch_host.restart_on_change(

test-requirements.txt

@@ -2,5 +2,5 @@ coverage
 flake8
 stestr
 git+https://github.com/openstack-charmers/zaza.git#egg=zaza
-git+https://github.com/freyes/zaza-openstack-tests.git@keystone-openidc#egg=zaza.openstack
+git+https://github.com/openstack-charmers/zaza-openstack-tests.git#egg=zaza.openstack
 requests-mock

unit_tests/test_charm.py

@@ -1,3 +1,4 @@
+import json
 import logging
 import os
 import shutil
@@ -177,3 +178,25 @@ class TestCharm(BaseTestCharm):
             m.get(WELL_KNOWN_URL, json=well_known_url_content)
             self.assertRaises(charm.CharmConfigError,
                               self.harness.charm.find_missing_keys)
+
+    def test_update_websso_data(self):
+        rid = self.harness.add_relation('websso-fid-service-provider',
+                                        'openstack-dashboard')
+        self.harness.add_relation_unit(rid, 'openstack-dashboard/0')
+        self.harness.charm._update_websso_data()
+        data = self.harness.get_relation_data(rid, 'keystone-openidc/0')
+        options = self.harness.charm.options
+        expected = {'protocol-name': json.dumps(options.idp_id),
+                    'idp-name': json.dumps(options.protocol_id),
+                    'user-facing-name': json.dumps(options.user_facing_name)}
+        self.assertDictEqual(data, expected)
+
+        # check that on config-changed the data is updated on the relation.
+        self.harness.update_config(key_values={'user-facing-name': 'My IdP'})
+        self.harness.charm.options = charm.KeystoneOpenIDCOptions(
+            self.harness.charm
+        )
+        self.harness.charm._update_websso_data()
+        data = self.harness.get_relation_data(rid, 'keystone-openidc/0')
+        expected['user-facing-name'] = json.dumps('My IdP')
+        self.assertDictEqual(data, expected)