(Backport 52699) btrfs: Add properties state

salt/states/btrfs.py

@@ -32,6 +32,7 @@
 import logging
 import os.path
 import tempfile
+import traceback
 
 from salt.exceptions import CommandExecutionError
 from salt.ext import six
@@ -41,13 +42,14 @@
 __virtualname__ = 'btrfs'
 
 
-def _mount(device):
+def _mount(device, use_default):
     '''
     Mount the device in a temporary place.
     '''
+    opts = 'defaults' if use_default else 'subvol=/'
     dest = tempfile.mkdtemp()
     res = __states__['mount.mounted'](dest, device=device, fstype='btrfs',
-                                      opts='subvol=/', persist=False)
+                                      opts=opts, persist=False)
     if not res['result']:
         log.error('Cannot mount device %s in %s', device, dest)
         _umount(dest)
@@ -104,6 +106,7 @@ def __mount_device(action):
     def wrapper(*args, **kwargs):
         name = kwargs['name']
         device = kwargs['device']
+        use_default = kwargs.get('use_default', False)
 
         ret = {
             'name': name,
@@ -112,17 +115,20 @@ def wrapper(*args, **kwargs):
             'comment': ['Some error happends during the operation.'],
         }
         try:
-            dest = _mount(device)
-            if not dest:
-                msg = 'Device {} cannot be mounted'.format(device)
-                ret['comment'].append(msg)
-            kwargs['__dest'] = dest
+            if device:
+                dest = _mount(device, use_default)
+                if not dest:
+                    msg = 'Device {} cannot be mounted'.format(device)
+                    ret['comment'].append(msg)
+                kwargs['__dest'] = dest
             ret = action(*args, **kwargs)
-        except Exception as e:
-            log.exception('Encountered error mounting %s', device)
-            ret['comment'].append(six.text_type(e))
+        except Exception:
+            tb = six.text_type(traceback.format_exc())
+            log.exception('Exception captured in wrapper %s', tb)
+            ret['comment'].append(tb)
         finally:
-            _umount(dest)
+            if device:
+                _umount(dest)
         return ret
     return wrapper
 
@@ -175,7 +181,7 @@ def subvolume_created(name, device, qgroupids=None, set_default=False,
     if __opts__['test']:
         ret['result'] = None
         if not exists:
-            ret['comment'].append('Subvolume {} will be created'.format(name))
+            ret['changes'][name] = 'Subvolume {} will be created'.format(name)
         return ret
 
     if not exists:
@@ -239,7 +245,7 @@ def subvolume_deleted(name, device, commit=False, __dest=None):
     if __opts__['test']:
         ret['result'] = None
         if exists:
-            ret['comment'].append('Subvolume {} will be removed'.format(name))
+            ret['changes'][name] = 'Subvolume {} will be removed'.format(name)
         return ret
 
     # If commit is set, we wait until all is over
@@ -256,3 +262,124 @@ def subvolume_deleted(name, device, commit=False, __dest=None):
 
     ret['result'] = True
     return ret
+
+
+def _diff_properties(expected, current):
+    '''Calculate the difference between the current and the expected
+    properties
+
+    * 'expected' is expressed in a dictionary like: {'property': value}
+
+    * 'current' contains the same format retuned by 'btrfs.properties'
+
+    If the property is not available, will throw an exception.
+
+    '''
+    difference = {}
+    for _property, value in expected.items():
+        current_value = current[_property]['value']
+        if value is False and current_value == 'N/A':
+            needs_update = False
+        elif value != current_value:
+            needs_update = True
+        else:
+            needs_update = False
+        if needs_update:
+            difference[_property] = value
+    return difference
+
+
+@__mount_device
+def properties(name, device, use_default=False, __dest=None, **properties):
+    '''
+    Makes sure that a list of properties are set in a subvolume, file
+    or device.
+
+    name
+        Name of the object to change
+
+    device
+        Device where the object lives, if None, the device will be in
+        name
+
+    use_default
+        If True, this subvolume will be resolved to the default
+        subvolume assigned during the create operation
+
+    properties
+        Dictionary of properties
+
+    Valid properties are 'ro', 'label' or 'compression'. Check the
+    documentation to see where those properties are valid for each
+    object.
+
+    '''
+    ret = {
+        'name': name,
+        'result': False,
+        'changes': {},
+        'comment': [],
+    }
+
+    # 'name' will have always the name of the object that we want to
+    # change, but if the object is a device, we do not repeat it again
+    # in 'device'. This makes device sometimes optional.
+    if device:
+        if os.path.isabs(name):
+            path = os.path.join(__dest, os.path.relpath(name, os.path.sep))
+        else:
+            path = os.path.join(__dest, name)
+    else:
+        path = name
+
+    if not os.path.exists(path):
+        ret['comment'].append('Object {} not found'.format(name))
+        return ret
+
+    # Convert the booleans to lowercase
+    properties = {k: v if type(v) is not bool else str(v).lower()
+                  for k, v in properties.items()}
+
+    current_properties = {}
+    try:
+        current_properties = __salt__['btrfs.properties'](path)
+    except CommandExecutionError as e:
+        ret['comment'].append('Error reading properties from {}'.format(name))
+        ret['comment'].append('Current error {}'.format(e))
+        return ret
+
+    try:
+        properties_to_set = _diff_properties(properties, current_properties)
+    except KeyError:
+        ret['comment'].append('Some property not found in {}'.format(name))
+        return ret
+
+    if __opts__['test']:
+        ret['result'] = None
+        if properties_to_set:
+            ret['changes'] = properties_to_set
+        else:
+            msg = 'No properties will be changed in {}'.format(name)
+            ret['comment'].append(msg)
+        return ret
+
+    if properties_to_set:
+        _properties = ','.join(
+            '{}={}'.format(k, v) for k, v in properties_to_set.items())
+        __salt__['btrfs.properties'](path, set=_properties)
+
+        current_properties = __salt__['btrfs.properties'](path)
+        properties_failed = _diff_properties(properties, current_properties)
+        if properties_failed:
+            msg = 'Properties {} failed to be changed in {}'.format(
+                properties_failed, name)
+            ret['comment'].append(msg)
+            return ret
+
+        ret['comment'].append('Properties changed in {}'.format(name))
+        ret['changes'] = properties_to_set
+    else:
+        ret['comment'].append('Properties not changed in {}'.format(name))
+
+    ret['result'] = True
+    return ret