Merge ~adam-collard/maas:rsd-ws-handler into maas:master

[Adam Collard]

Add websocket handler for navigation_options

Front-end can quickly determine if any RSD hosts are present.

[Blake Rouse (blake-rouse)]

Looks good to me!

review: Approve

[MAAS Lander (maas-lander)]

LANDING
-b rsd-ws-handler lp:~adam-collard/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED BUILD
LOG: http://maas-ci-jenkins.internal:8080/job/maas/job/branch-tester/6075/consoleText

[MAAS Lander (maas-lander)]

LANDING
-b rsd-ws-handler lp:~adam-collard/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED BUILD
LOG: http://maas-ci-jenkins.internal:8080/job/maas/job/branch-tester/6076/consoleText

diff --git a/src/maasserver/models/bmc.py b/src/maasserver/models/bmc.py
index 711e756..dbbd1cc 100644
--- a/src/maasserver/models/bmc.py
+++ b/src/maasserver/models/bmc.py
@@ -522,8 +522,8 @@ class PodManager(BaseBMCManager):
 
         :param user: The user that should be used in the permission check.
         :type user: User_
-        :param user: Type of access requested.
-        :type user: `PodPermission`
+        :param perm: Type of access requested.
+        :type perm: `PodPermission`
 
         .. _User: https://
            docs.djangoproject.com/en/dev/topics/auth/
@@ -576,6 +576,20 @@ class PodManager(BaseBMCManager):
         else:
             raise PermissionDenied()
 
+    def have_rsd(self, user, perm):
+        """Are there any RSD hosts?
+
+        :param user: The user that should be used in the permission check.
+        :type user: User_
+        :param perm: Type of access requested.
+        :type perm: `PodPermission`
+
+        .. _User: https://
+           docs.djangoproject.com/en/dev/topics/auth/
+           #django.contrib.auth.models.User
+        """
+        return self.get_pods(user, perm).filter(power_type='rsd').exists()
+
 
 class Pod(BMC):
     """A `Pod` represents a `BMC` that controls multiple machines."""
diff --git a/src/maasserver/models/tests/test_bmc.py b/src/maasserver/models/tests/test_bmc.py
index 41ff534..c9e6c79 100644
--- a/src/maasserver/models/tests/test_bmc.py
+++ b/src/maasserver/models/tests/test_bmc.py
@@ -713,6 +713,28 @@ class TestPodManager(MAASServerTestCase):
         self.assertEqual(
             pod, Pod.objects.get_pod_or_404(pod.id, user, PodPermission.view))
 
+    def test_have_rsd_with_no_rsd(self):
+        factory.make_Pod()
+        user = factory.make_User()
+        self.patch(user, 'has_perm').return_value = True
+        self.assertFalse(
+            Pod.objects.have_rsd(user, PodPermission.view))
+
+    def test_have_rsd_with_rsd(self):
+        factory.make_Pod(pod_type='rsd')
+        user = factory.make_User()
+        self.patch(user, 'has_perm').return_value = True
+        self.assertTrue(
+            Pod.objects.have_rsd(user, PodPermission.view))
+
+    def test_have_rsd_with_forbidden_rsd(self):
+        self.enable_rbac()
+        factory.make_Pod(pod_type='rsd')
+        user = factory.make_User()
+        self.patch(user, 'has_perm').return_value = False
+        self.assertFalse(
+            Pod.objects.have_rsd(user, PodPermission.view))
+
 
 class TestPod(MAASServerTestCase):
 
diff --git a/src/maasserver/websockets/handlers/general.py b/src/maasserver/websockets/handlers/general.py
index b85960d..1a5bee7 100644
--- a/src/maasserver/websockets/handlers/general.py
+++ b/src/maasserver/websockets/handlers/general.py
@@ -21,7 +21,10 @@ from maasserver.models.config import Config
 from maasserver.models.node import Node
 from maasserver.models.packagerepository import PackageRepository
 from maasserver.node_action import ACTIONS_DICT
-from maasserver.permissions import NodePermission
+from maasserver.permissions import (
+    NodePermission,
+    PodPermission,
+)
 from maasserver.utils.osystems import (
     list_all_usable_hwe_kernels,
     list_all_usable_osystems,
@@ -58,6 +61,7 @@ class GeneralHandler(Handler):
             'version',
             'power_types',
             'release_options',
+            'navigation_options',
             ]
 
     def architectures(self, params):
@@ -197,3 +201,10 @@ class GeneralHandler(Handler):
             "quick_erase": Config.objects.get_config(
                 "disk_erase_with_quick_erase"),
         }
+
+    def navigation_options(self, params):
+        """Return the options for navigation."""
+        from maasserver.models.bmc import Pod  # circular import
+        return {
+            "rsd": Pod.objects.have_rsd(self.user, PodPermission.view)
+        }
diff --git a/src/maasserver/websockets/handlers/tests/test_general.py b/src/maasserver/websockets/handlers/tests/test_general.py
index 2ee572e..e269890 100644
--- a/src/maasserver/websockets/handlers/tests/test_general.py
+++ b/src/maasserver/websockets/handlers/tests/test_general.py
@@ -257,3 +257,8 @@ class TestGeneralHandler(MAASServerTestCase):
             "secure_erase": secure_erase,
             "quick_erase": quick_erase,
         }, handler.release_options({}))
+
+    def test_navigation_options(self):
+        handler = GeneralHandler(factory.make_User(), {}, None)
+        self.assertEqual(
+            {"rsd": False}, handler.navigation_options({}))