added support for JSON and YAML properties files

1 files changed, 206 insertions, 23 deletions

diff --git a/src/lib/Bcfg2/Server/Plugins/Properties.py b/src/lib/Bcfg2/Server/Plugins/Properties.py
index d9e622645..aef5238c6 100644
--- a/src/lib/Bcfg2/Server/Plugins/Properties.py
+++ b/src/lib/Bcfg2/Server/Plugins/Properties.py
@@ -16,17 +16,42 @@ try:
 except ImportError:
     HAS_CRYPTO = False
 
+try:
+    import json
+    HAS_JSON = True
+except ImportError:
+    try:
+        import simplejson as json
+        HAS_JSON = True
+    except ImportError:
+        HAS_JSON = False
+
+try:
+    import yaml
+    HAS_YAML = True
+except ImportError:
+    HAS_YAML = False
+
 LOGGER = logging.getLogger(__name__)
 
 SETUP = None
 
 
-class PropertyFile(Bcfg2.Server.Plugin.StructFile):
-    """ Class for properties files. """
+class PropertyFile(object):
+    """ Base Properties file handler """
+
+    def __init__(self, name):
+        """
+        :param name: The filename of this properties file.
+
+        .. automethod:: _write
+        """
+        self.name = name
 
     def write(self):
         """ Write the data in this data structure back to the property
-        file """
+        file. This public method performs checking to ensure that
+        writing is possible and then calls :func:`_write`. """
         if not SETUP.cfp.getboolean("properties", "writes_enabled",
                                     default=True):
             msg = "Properties files write-back is disabled in the " + \
@@ -39,19 +64,123 @@ class PropertyFile(Bcfg2.Server.Plugin.StructFile):
             msg = "Cannot write %s: %s" % (self.name, sys.exc_info()[1])
             LOGGER.error(msg)
             raise PluginExecutionError(msg)
-
         try:
-            open(self.name, "wb").write(
-                lxml.etree.tostring(self.xdata,
-                                    xml_declaration=False,
-                                    pretty_print=True).decode('UTF-8'))
-            return True
+            return self._write()
         except IOError:
             err = sys.exc_info()[1]
             msg = "Failed to write %s: %s" % (self.name, err)
             LOGGER.error(msg)
             raise PluginExecutionError(msg)
 
+    def _write(self):
+        """ Write the data in this data structure back to the property
+        file. """
+        raise NotImplementedError
+
+    def validate_data(self):
+        """ Verify that the data in this file is valid. """
+        raise NotImplementedError
+
+    def get_additional_data(self, metadata):  # pylint: disable=W0613
+        """ Get file data for inclusion in client metadata. """
+        return copy.copy(self)
+
+
+class JSONPropertyFile(Bcfg2.Server.Plugin.FileBacked, PropertyFile):
+    """ Handle JSON Properties files. """
+
+    def __init__(self, name, fam=None):
+        Bcfg2.Server.Plugin.FileBacked.__init__(self, name, fam=fam)
+        PropertyFile.__init__(self, name)
+        self.json = None
+    __init__.__doc__ = Bcfg2.Server.Plugin.FileBacked.__init__.__doc__
+
+    def Index(self):
+        try:
+            self.json = json.loads(self.data)
+        except ValueError:
+            err = sys.exc_info()[1]
+            raise PluginExecutionError("Could not load JSON data from %s: %s" %
+                                       (self.name, err))
+    Index.__doc__ = Bcfg2.Server.Plugin.FileBacked.Index.__doc__
+
+    def _write(self):
+        json.dump(self.json, open(self.name, 'wb'))
+        return True
+    _write.__doc__ = PropertyFile._write.__doc__
+
+    def validate_data(self):
+        try:
+            json.dumps(self.json)
+        except:
+            err = sys.exc_info()[1]
+            raise PluginExecutionError("Data for %s cannot be dumped to JSON: "
+                                       "%s" % (self.name, err))
+    validate_data.__doc__ = PropertyFile.validate_data.__doc__
+
+    def __str__(self):
+        return str(self.json)
+
+    def __repr__(self):
+        return repr(self.json)
+
+
+class YAMLPropertyFile(Bcfg2.Server.Plugin.FileBacked, PropertyFile):
+    """ Handle YAML Properties files. """
+
+    def __init__(self, name, fam=None):
+        Bcfg2.Server.Plugin.FileBacked.__init__(self, name, fam=fam)
+        PropertyFile.__init__(self, name)
+        self.yaml = None
+    __init__.__doc__ = Bcfg2.Server.Plugin.FileBacked.__init__.__doc__
+
+    def Index(self):
+        try:
+            self.yaml = yaml.load(self.data)
+        except yaml.YAMLError:
+            err = sys.exc_info()[1]
+            raise PluginExecutionError("Could not load YAML data from %s: %s" %
+                                       (self.name, err))
+    Index.__doc__ = Bcfg2.Server.Plugin.FileBacked.Index.__doc__
+
+    def _write(self):
+        yaml.dump(self.yaml, open(self.name, 'wb'))
+        return True
+    _write.__doc__ = PropertyFile._write.__doc__
+
+    def validate_data(self):
+        try:
+            yaml.dump(self.yaml)
+        except yaml.YAMLError:
+            err = sys.exc_info()[1]
+            raise PluginExecutionError("Data for %s cannot be dumped to YAML: "
+                                       "%s" % (self.name, err))
+    validate_data.__doc__ = PropertyFile.validate_data.__doc__
+
+    def __str__(self):
+        return str(self.yaml)
+
+    def __repr__(self):
+        return repr(self.yaml)
+
+
+class XMLPropertyFile(Bcfg2.Server.Plugin.StructFile, PropertyFile):
+    """ Handle XML Properties files. """
+
+    def __init__(self, name, fam=None, should_monitor=False):
+        Bcfg2.Server.Plugin.StructFile.__init__(self, name, fam=fam,
+                                                should_monitor=should_monitor)
+        PropertyFile.__init__(self, name)
+    __init__.__doc__ = Bcfg2.Server.Plugin.StructFile.__init__.__doc__
+
+    def _write(self):
+        open(self.name, "wb").write(
+            lxml.etree.tostring(self.xdata,
+                                xml_declaration=False,
+                                pretty_print=True).decode('UTF-8'))
+        return True
+    _write.__doc__ = PropertyFile._write.__doc__
+
     def validate_data(self):
         """ ensure that the data in this object validates against the
         XML schema for this property file (if a schema exists) """
@@ -73,6 +202,7 @@ class PropertyFile(Bcfg2.Server.Plugin.StructFile):
                                        self.name)
         else:
             return True
+    validate_data.__doc__ = PropertyFile.validate_data.__doc__
 
     def Index(self):
         Bcfg2.Server.Plugin.StructFile.Index(self)
@@ -89,6 +219,7 @@ class PropertyFile(Bcfg2.Server.Plugin.StructFile):
                                                                   self.name)
                     LOGGER.error(msg)
                     raise PluginExecutionError(msg)
+    Index.__doc__ = Bcfg2.Server.Plugin.StructFile.Index.__doc__
 
     def _decrypt(self, element):
         """ Decrypt a single encrypted properties file element """
@@ -111,19 +242,77 @@ class PropertyFile(Bcfg2.Server.Plugin.StructFile):
                                       algorithm=get_algorithm(SETUP))
         raise EVPError("Failed to decrypt")
 
+    def get_additional_data(self, metadata):
+        if SETUP.cfp.getboolean("properties", "automatch", default=False):
+            default_automatch = "true"
+        else:
+            default_automatch = "false"
+
+        if self.xdata.get("automatch", default_automatch).lower() == "true":
+            return self.XMLMatch(metadata)
+        else:
+            return copy.copy(self)
+
+    def __str__(self):
+        return str(self.xdata)
+
+    def __repr__(self):
+        return repr(self.xdata)
+
 
 class PropDirectoryBacked(Bcfg2.Server.Plugin.DirectoryBacked):
-    """ A collection of properties files """
-    __child__ = PropertyFile
-    patterns = re.compile(r'.*\.xml$')
+    """ A collection of properties files. """
+    extensions = ["xml"]
+    if HAS_JSON:
+        extensions.append("json")
+    if HAS_YAML:
+        extensions.extend(["yaml", "yml"])
+
+    #: Only track and include files whose names and paths match this
+    #: regex.  Created on-the-fly based on which libraries are
+    #: installed (and thus which data formats are supported).
+    #: Candidates are ``.xml`` (always supported), ``.json``,
+    #: ``.yaml``, and ``.yml``.
+    patterns = re.compile(r'.*\.%s$' % '|'.join(extensions))
+
+    #: Ignore XML schema (``.xsd``) files
     ignore = re.compile(r'.*\.xsd$')
 
+    def __init__(self, data, fam):
+        Bcfg2.Server.Plugin.DirectoryBacked.__init__(self, data, fam)
+
+        #: Instead of creating children of this object with a static
+        #: object, we use :func:`property_dispatcher` to create a
+        #: child of the appropriate subclass of :class:`PropertyFile`
+        self.__child__ = self.property_dispatcher
+    __init__.__doc__ = Bcfg2.Server.Plugin.DirectoryBacked.__init__.__doc__
+
+    def property_dispatcher(self, fname, fam):
+        """ Dispatch an event on a Properties file to the
+        appropriate object.
+
+        :param fname: The name of the file that received the event
+        :type fname: string
+        :param fam: The file monitor the event was received by
+        :type fam: Bcfg2.Server.FileMonitor.FileMonitor
+        :returns: An object of the appropriate subclass of
+                  :class:`PropertyFile`
+        """
+        if fname.endswith(".xml"):
+            return XMLPropertyFile(fname, fam)
+        elif HAS_JSON and fname.endswith(".json"):
+            return JSONPropertyFile(fname, fam)
+        elif HAS_YAML and (fname.endswith(".yaml") or fname.endswith(".yml")):
+            return YAMLPropertyFile(fname, fam)
+        else:
+            raise Bcfg2.Server.Plugin.PluginExecutionError(
+                "Properties: Unknown extension %s" % fname)
+
 
 class Properties(Bcfg2.Server.Plugin.Plugin,
                  Bcfg2.Server.Plugin.Connector):
     """ The properties plugin maps property files into client metadata
     instances. """
-    name = 'Properties'
 
     def __init__(self, core, datastore):
         global SETUP  # pylint: disable=W0603
@@ -138,18 +327,12 @@ class Properties(Bcfg2.Server.Plugin.Plugin,
             raise Bcfg2.Server.Plugin.PluginInitError
 
         SETUP = core.setup
+    __init__.__doc__ = Bcfg2.Server.Plugin.Plugin.__init__.__doc__
 
     def get_additional_data(self, metadata):
-        if self.core.setup.cfp.getboolean("properties", "automatch",
-                                          default=False):
-            default_automatch = "true"
-        else:
-            default_automatch = "false"
         rv = dict()
         for fname, pfile in self.store.entries.items():
-            if pfile.xdata.get("automatch",
-                               default_automatch).lower() == "true":
-                rv[fname] = pfile.XMLMatch(metadata)
-            else:
-                rv[fname] = copy.copy(pfile)
+            rv[fname] = pfile.get_additional_data(metadata)
         return rv
+    get_additional_data.__doc__ = \
+        Bcfg2.Server.Plugin.Connector.get_additional_data.__doc__