Initial TGenshi checking (from jcollie)

git-svn-id: https://svn.mcs.anl.gov/repos/bcfg/trunk/bcfg2@3476 ce84e21b-d406-0410-9b95-82705330c041

1 files changed, 145 insertions, 0 deletions

diff --git a/src/lib/Server/Plugins/TGenshi.py b/src/lib/Server/Plugins/TGenshi.py
new file mode 100644
index 000000000..da6dcf956
--- /dev/null
+++ b/src/lib/Server/Plugins/TGenshi.py
@@ -0,0 +1,145 @@
+'''This module implements a templating generator based on Genshi'''
+__revision__ = '$Revision$'
+
+from genshi.template import TemplateLoader, TextTemplate, MarkupTemplate, TemplateError
+import logging, lxml.etree, posixpath, re, os
+import Bcfg2.Server.Plugin
+
+logger = logging.getLogger('Bcfg2.Plugins.TGenshi')
+info = re.compile('^owner:(\s)*(?P<owner>\w+)$|group:(\s)*(?P<group>\w+)$|' +
+                  'perms:(\s)*(?P<perms>\w+)$')
+
+class TemplateFile:
+    '''Template file creates Genshi template structures for the loaded file'''
+    def __init__(self, name, loader, properties):
+        self.name = name
+        self.states = {'template': False, 'info': False}
+        self.metadata = {'owner': 'root', 'group': 'root', 'perms': '0644'}
+        self.properties = properties
+        self.loader = loader
+        
+    def HandleEvent(self, event):
+        '''Handle all fs events for this template'''
+        if event.filename in ['template.xml', 'template.txt']:
+            try:
+                if event.filename.endswith('.txt'):
+                    self.template = self.loader.load(os.path.join(self.name[1:], event.filename), cls=TextTemplate)
+                else:
+                    self.template = self.loader.load(os.path.join(self.name[1:], event.filename), cls=MarkupTemplate)
+            except TemplateError, terror:
+                logger.error('Genshi template error: %s' % terror)
+            
+        elif event.filename == 'info':
+            for line in open(self.name + '/info').readlines():
+                match = info.match(line)
+                if not match:
+                    logger.warning("Failed to match line: %s"%line)
+                    continue
+                else:
+                    mgd = match.groupdict()
+                    if mgd['owner']:
+                        self.metadata['owner'] = mgd['owner']
+                    elif mgd['group']:
+                        self.metadata['group'] = mgd['group']
+                    elif mgd['perms']:
+                        self.metadata['perms'] = mgd['perms']
+                        if len(self.metadata['perms']) == 3:
+                            self.metadata['perms'] = "0%s" % (self.metadata['perms'])              
+        else:
+            logger.info('Ignoring event for %s' % event.filename)
+            
+    def BuildFile(self, entry, metadata):
+        '''Build literal file information'''
+        try:
+            stream = self.template.generate(name=entry.get('name'), metadata=metadata, properties=self.properties)
+            if isinstance(self.template, TextTemplate):
+                entry.text = stream.render('text')
+            else:
+                entry.text = stream.render('xml')
+        except TemplateError, terror:
+            logger.error('Genshi template error: %s' % terror)
+            raise Bcfg2.Server.Plugin.PluginExecutionError
+        [entry.attrib.__setitem__(key, value) for (key, value) in self.metadata.iteritems()]
+
+class GenshiProperties(Bcfg2.Server.Plugin.SingleXMLFileBacked):
+    '''Class for Genshi properties'''
+    def Index(self):
+        '''Build data into an elementtree object for templating usage'''
+        try:
+            self.properties = lxml.etree.XML(self.data)
+            del self.data
+        except lxml.etree.XMLSyntaxError:
+            logger.error("Failed to parse properties")
+
+class FakeProperties:
+    '''Dummy class used when properties dont exist'''
+    def __init__(self):
+        self.properties = lxml.etree.Element("Properties")
+
+class TGenshi(Bcfg2.Server.Plugin.Plugin):
+    '''The TGenshi generator implements a templating mechanism for configuration files'''
+    __name__ = 'TGenshi'
+    __version__ = '$Id$'
+    __author__ = 'jeff@ocjtech.us'
+
+    def __init__(self, core, datastore):
+        Bcfg2.Server.Plugin.Plugin.__init__(self, core, datastore)
+        if self.data[-1] == '/':
+            self.data = self.data[:-1]
+        self.Entries['ConfigFile'] = {}
+        self.entries = {}
+        self.handles = {}
+        self.loader = TemplateLoader(self.data, auto_reload=True)
+        self.AddDirectoryMonitor('')
+        try:
+            self.properties = GenshiProperties('%s/../etc/properties.xml' \
+                                               % (self.data), self.core.fam)
+        except:
+            self.properties = FakeProperties()
+            self.logger.info("Failed to read properties file; TGenshi properties disabled")
+
+    def BuildEntry(self, entry, metadata):
+        '''Dispatch fetch calls to the correct object'''
+        self.entries[entry.get('name')].BuildFile(entry, metadata)
+
+    def HandleEvent(self, event):
+        '''Unified FAM event handler for DirShadow'''
+        action = event.code2str()
+        if event.filename[0] == '/':
+            return
+        epath = "".join([self.data, self.handles[event.requestID], event.filename])
+        if event.filename in ['info', 'template.xml', 'template.txt']:
+            identifier = self.handles[event.requestID][:-1]
+        else:
+            identifier = self.handles[event.requestID] + event.filename
+        if action in ['exists', 'created']:
+            if posixpath.isdir(epath):
+                self.AddDirectoryMonitor(epath[len(self.data):])
+            elif event.filename in ['info', 'template.xml', 'template.txt']:
+                if not self.entries.has_key(identifier):
+                    self.entries[identifier] = TemplateFile(identifier, self.loader, self.properties)
+                    self.Entries['ConfigFile'][identifier] = self.BuildEntry
+                self.entries[identifier].HandleEvent(event)
+            else:
+                logger.info('Not creating template for %s' % identifier)
+        elif action == 'changed':
+            if self.entries.has_key(identifier):
+                self.entries[identifier].HandleEvent(event)
+        elif action == 'deleted':
+            if event.filename in ['template.xml', 'template.txt'] and self.entries.has_key(identifier):
+                del self.entries[identifier]
+                del self.Entries['ConfigFile'][identifier]
+                                 
+    def AddDirectoryMonitor(self, relative):
+        '''Add new directory to FAM structures'''
+        if not relative:
+            relative = '/'
+        if relative[-1] != '/':
+            relative += '/'
+        name = self.data + relative
+        if relative not in self.handles.values():
+            if not posixpath.isdir(name):
+                print "Genshi: Failed to open directory %s" % (name)
+                return
+            reqid = self.core.fam.AddMonitor(name, self)
+            self.handles[reqid] = relative