From f3acd81a314d4c2b491a44dd3df37661910e6c17 Mon Sep 17 00:00:00 2001
From: Frode Nordahl <frode.nordahl@canonical.com>
Date: Wed, 13 Mar 2019 11:26:19 +0100
Subject: [PATCH] Use ``ceph-conf`` to retrieve default values

The ``ceph`` command expects connection to a running cluster even
if it does not use it.

Change-Id: Ied3edf63706e2d48d2ea09056bc6d6508e9e3e0f
Closes-Bug: #1819852
---
 hooks/utils.py                | 13 ++++++-------
 unit_tests/test_ceph_utils.py |  9 ++++++---
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/hooks/utils.py b/hooks/utils.py
index 158d5912..0ac0405f 100644
--- a/hooks/utils.py
+++ b/hooks/utils.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 import re
 import socket
 import subprocess
@@ -183,14 +184,12 @@ def get_default_rbd_features():
 
     :returns: Installed Ceph's Default vaule for ``rbd_default_features``
     :rtype: int
-    :raises: subprocess.CalledProcessError
+    :raises: IndexError, json.JSONDecodeError, subprocess.CalledProcessError
     """
-    output = subprocess.check_output(
-        ['ceph', '-c', '/dev/null', '--show-config'],
-        universal_newlines=True)
-    for line in output.splitlines():
-        if 'rbd_default_features' in line:
-            return int(line.split('=')[1].lstrip().rstrip())
+    ceph_conf = json.loads(subprocess.check_output(
+        ['ceph-conf', '-c', '/dev/null', '-D', '--format', 'json'],
+        universal_newlines=True))
+    return int(ceph_conf['rbd_default_features'])
 
 
 def add_rbd_mirror_features(rbd_features):
diff --git a/unit_tests/test_ceph_utils.py b/unit_tests/test_ceph_utils.py
index 9765b8b6..076429a3 100644
--- a/unit_tests/test_ceph_utils.py
+++ b/unit_tests/test_ceph_utils.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 import mock
 
 import test_utils
@@ -40,13 +41,15 @@ class CephUtilsTestCase(test_utils.CharmTestCase):
 
     @mock.patch.object(utils.subprocess, 'check_output')
     def test_get_default_rbd_features(self, _check_output):
-        _check_output.return_value = ('a = b\nrbd_default_features = 61\n'
-                                      'c = d\n')
+        _check_output.return_value = json.dumps(
+            {'a': 'b',
+             'rbd_default_features': '61',
+             'c': 'd'})
         self.assertEquals(
             utils.get_default_rbd_features(),
             61)
         _check_output.assert_called_once_with(
-            ['ceph', '-c', '/dev/null', '--show-config'],
+            ['ceph-conf', '-c', '/dev/null', '-D', '--format', 'json'],
             universal_newlines=True)
 
     def test_add_mirror_rbd_features(self):