Adds existence verification for config values

Multisite config values (realm, zonegroup, zone) are written
to ceph.conf as the defaults without verifying their existence, this
causes failure for commands which use the default values.

Closes-Bug: #1987127
Change-Id: I0ab4df34f0000339227e5d5b80352355ea7bd36e

hooks/ceph_radosgw_context.py

@@ -18,6 +18,7 @@ import socket
 import tempfile
 import shutil
 
+import multisite
 from charmhelpers.contrib.openstack import context
 from charmhelpers.contrib.hahelpers.cluster import (
     determine_api_port,
@@ -307,9 +308,17 @@ class MonContext(context.CephContext):
         if self.context_complete(ctxt):
             # Multi-site zone configuration is optional,
             # so add after assessment
-            ctxt['rgw_zone'] = config('zone')
+            zone = config('zone')
-            ctxt['rgw_zonegroup'] = config('zonegroup')
+            zonegroup = config('zonegroup')
-            ctxt['rgw_realm'] = config('realm')
+            realm = config('realm')
+            log("config: zone {} zonegroup {} realm {}"
+                .format(zone, zonegroup, realm), level=DEBUG)
+            if zone in multisite.plain_list('zone'):
+                ctxt['rgw_zone'] = zone
+            if zonegroup in multisite.plain_list('zonegroup'):
+                ctxt['rgw_zonegroup'] = zonegroup
+            if realm in multisite.plain_list('realm'):
+                ctxt['rgw_realm'] = realm
             return ctxt
 
         return {}

hooks/hooks.py

@@ -810,6 +810,7 @@ def master_relation_joined(relation_id=None):
             'Mutation detected. Restarting {}.'.format(service_name()),
             'INFO')
         multisite.update_period(zonegroup=zonegroup, zone=zone)
+        CONFIGS.write_all()
         service_restart(service_name())
         leader_set(restart_nonce=str(uuid.uuid4()))
     else:
@@ -898,6 +899,7 @@ def slave_relation_changed(relation_id=None, unit=None):
             'Mutation detected. Restarting {}.'.format(service_name()),
             'INFO')
         multisite.update_period(zonegroup=zonegroup, zone=zone)
+        CONFIGS.write_all()
         service_restart(service_name())
         leader_set(restart_nonce=str(uuid.uuid4()))
     else:

hooks/multisite.py

@@ -81,6 +81,35 @@ def _list(key):
         return []
 
 
+def plain_list(key):
+    """Simple Implementation for list_*, where execution may fail expectedly.
+
+    On failure, retries are not attempted and empty list is returned.
+
+    :param key: string for required resource (zone, zonegroup, realm, user)
+    :type key: str
+    :return: list of specified entities found
+    :rtype: list
+    """
+    cmd = [
+        RGW_ADMIN, '--id={}'.format(_key_name()),
+        key, 'list'
+    ]
+    try:
+        result = json.loads(subprocess.check_output(
+            cmd, stderr=subprocess.PIPE
+        ).decode('UTF-8'))
+        hookenv.log("Results: {}".format(result), level=hookenv.DEBUG)
+        if isinstance(result, dict):
+            return result['{}s'.format(key)]
+        else:
+            return result
+    except subprocess.CalledProcessError:
+        return []
+    except TypeError:
+        return []
+
+
 @decorators.retry_on_exception(num_retries=5, base_delay=3,
                                exc_type=ValueError)
 def list_zones(retry_on_empty=False):
@@ -646,7 +675,7 @@ def get_local_zone(zonegroup):
     if zonegroup_info is None:
         hookenv.log("Failed to fetch zonegroup ({}) info".format(zonegroup),
                     level=hookenv.ERROR)
-        return None
+        return None, None
 
     # zonegroup info always contains self name and zones list so fetching
     # directly is safe.
@@ -660,7 +689,7 @@ def get_local_zone(zonegroup):
         "No local zone configured for zonegroup ({})".format(zonegroup),
         level=hookenv.ERROR
     )
-    return None
+    return None, None
 
 
 def rename_multisite_config(zonegroups, new_zonegroup_name,

unit_tests/test_ceph_radosgw_context.py

@@ -33,6 +33,7 @@ TO_PATCH = [
     'determine_api_port',
     'cmp_pkgrevno',
     'leader_get',
+    'multisite',
     'utils',
 ]
 
@@ -83,6 +84,17 @@ class MonContextTest(CharmTestCase):
         self.test_config.set('zonegroup', 'zonegroup1')
         self.test_config.set('realm', 'realmX')
 
+    @staticmethod
+    def plain_list_stub(key):
+        if key == "zone":
+            return ["default"]
+        if key == "zonegroup":
+            return ["zonegroup1"]
+        if key == "realm":
+            return ["realmX"]
+        else:
+            return []
+
     @patch.object(ceph, 'config', lambda *args:
                   '{"client.radosgw.gateway": {"rgw init timeout": 60}}')
     @patch.object(context, 'ensure_host_resolvable_v6')
@@ -104,6 +116,7 @@ class MonContextTest(CharmTestCase):
         self.relation_get.side_effect = _relation_get
         self.relation_ids.return_value = ['mon:6']
         self.related_units.return_value = ['ceph/0', 'ceph/1', 'ceph/2']
+        self.multisite.plain_list = self.plain_list_stub
         self.determine_api_port.return_value = 70
         expect = {
             'auth_supported': 'cephx',
@@ -156,6 +169,7 @@ class MonContextTest(CharmTestCase):
 
         self.relation_get.side_effect = _relation_get
         self.relation_ids.return_value = ['mon:6']
+        self.multisite.plain_list = self.plain_list_stub
         self.related_units.return_value = ['ceph-proxy/0']
         self.determine_api_port.return_value = 70
         expect = {
@@ -219,6 +233,7 @@ class MonContextTest(CharmTestCase):
         self.relation_get.side_effect = _relation_get
         self.relation_ids.return_value = ['mon:6']
         self.related_units.return_value = ['ceph/0', 'ceph/1', 'ceph/2']
+        self.multisite.plain_list = self.plain_list_stub
         self.determine_api_port.return_value = 70
         expect = {
             'auth_supported': 'none',
@@ -264,6 +279,7 @@ class MonContextTest(CharmTestCase):
         self.relation_ids.return_value = ['mon:6']
         self.related_units.return_value = ['ceph/0', 'ceph/1', 'ceph/2']
         self.determine_api_port.return_value = 70
+        self.multisite.plain_list = self.plain_list_stub
         expect = {
             'auth_supported': 'cephx',
             'hostname': 'testhost',
@@ -365,6 +381,7 @@ class MonContextTest(CharmTestCase):
         self.relation_get.side_effect = _relation_get
         self.relation_ids.return_value = ['mon:6']
         self.related_units.return_value = ['ceph/0', 'ceph/1', 'ceph/2']
+        self.multisite.plain_list = self.plain_list_stub
         self.determine_api_port.return_value = 70
         expect = {
             'auth_supported': 'cephx',