Merge pull request #30941 from rallytime/bp-30879

Back-port #30879 to 2015.8

salt/states/dockerng.py

@@ -2081,12 +2081,17 @@ def network_absent(name, driver=None):
     return ret
 
 
-def volume_present(name, driver=None, driver_opts=None):
+def volume_present(name, driver=None, driver_opts=None, force=False):
     '''
     Ensure that a volume is present.
 
     .. versionadded:: 2015.8.4
 
+    .. versionchanged:: 2015.8.6
+        This function no longer deletes and re-creates a volume if the
+        existing volume's driver does not match the ``driver``
+        parameter (unless the ``force`` parameter is set to ``True``).
+
     name
         Name of the volume
 
@@ -2100,7 +2105,16 @@ def volume_present(name, driver=None, driver_opts=None):
         explicitly name Docker's default driver here.)
 
     driver_opts
-        Option for tha volume driver
+        Options for the volume driver
+
+    force : False
+        If the volume already exists but the existing volume's driver
+        does not match the driver specified by the ``driver``
+        parameter, this parameter controls whether the function errors
+        out (if ``False``) or deletes and re-creates the volume (if
+        ``True``).
+
+        .. versionadded:: 2015.8.6
 
     Usage Examples:
 
@@ -2152,6 +2166,12 @@ def volume_present(name, driver=None, driver_opts=None):
     # volume exits, check if driver is the same.
     volume = volumes[0]
     if driver is not None and volume['Driver'] != driver:
+        if not force:
+            ret['comment'] = "Driver for existing volume '{0}' ('{1}')" \
+                             " does not match specified driver ('{2}')" \
+                             " and force is False".format(
+                                 name, volume['Driver'], driver)
+            return ret
         try:
             ret['changes']['removed'] = __salt__['dockerng.remove_volume'](name)
         except Exception as exc:

tests/unit/states/dockerng_test.py

@@ -572,8 +572,23 @@ class DockerngTestCase(TestCase):
                 ret)
             self.assertEqual(orig_volumes, volumes)
 
-            # run it again, except with a different driver
+            # run it again with a different driver but don't force
             ret = dockerng_state.volume_present('volume_foo', driver='local')
+            self.assertEqual(
+                {
+                    'name': 'volume_foo',
+                    'comment': ("Driver for existing volume 'volume_foo'"
+                                " ('dummy_default') does not match specified"
+                                " driver ('local') and force is False"),
+                    'changes': {},
+                    'result': False,
+                },
+                ret)
+            self.assertEqual(orig_volumes, volumes)
+
+            # run it again with a different driver and force
+            ret = dockerng_state.volume_present(
+                'volume_foo', driver='local', force=True)
             self.assertEqual(
                 {
                     'name': 'volume_foo',
@@ -611,7 +626,8 @@ class DockerngTestCase(TestCase):
                         {'__salt__': __salt__}):
             ret = dockerng_state.volume_present(
                 'volume_foo',
-                driver='bar'
+                driver='bar',
+                force=True,
                 )
         dockerng_remove_volume.assert_called_with('volume_foo')
         dockerng_create_volume.assert_called_with('volume_foo',