Change to typed plugin system

git-svn-id: https://svn.mcs.anl.gov/repos/bcfg/trunk/bcfg2@4680 ce84e21b-d406-0410-9b95-82705330c041

11 files changed, 69 insertions, 155 deletions

diff --git a/src/lib/Server/Core.py b/src/lib/Server/Core.py
index 6a6264e9a..a5a484de9 100644
--- a/src/lib/Server/Core.py
+++ b/src/lib/Server/Core.py
@@ -233,28 +233,43 @@ class Core(object):
                 except ImportError, e:
                     logger.error("Failed to load plugin %s: %s" % (plugin, e))
                     continue
-                struct = getattr(mod, plugin)
+                plug = getattr(mod, plugin)
+                if plug.experimental:
+                    logger.info("Loading experimental plugin %s" % (plugin))
+                    logger.info("NOTE: Interface subject to change")
                 try:
-                    self.plugins[plugin] = struct(self, self.datastore)
+                    self.plugins[plugin] = plug(self, self.datastore)
                 except PluginInitError:
                     logger.error("Failed to instantiate plugin %s" % (plugin))
                 except:
                     logger.error("Unexpected instantiation failure for plugin %s" % (plugin), exc_info=1)
 
-        if 'Metadata' in self.plugins:
-            self.metadata = self.plugins['Metadata']
-        else:
-            raise CoreInitError, "No Metadata plugin loaded"
-        for plugin in structures:
-            if self.plugins.has_key(plugin):
-                self.structures.append(self.plugins[plugin])
-            else:
-                logger.error("Plugin %s not loaded. Not enabled as a Structure" % (plugin))
-        for plugin in generators:
-            if self.plugins.has_key(plugin):
-                self.generators.append(self.plugins[plugin])
-            else:
-                logger.error("Plugin %s not loaded. Not enabled as a Generator" % (plugin))
+        plugins = self.plugins.values()
+        while True:
+            plugin = plugins.pop()
+            if isinstance(plugin, Bcfg2.Server.Plugin.MetadataPlugin):
+                self.metadata = plugin
+                break
+            if not plugins:
+                raise CoreInitError, "No Metadata plugin loaded"
+        for plug_names, plug_tname, plug_type, collection in \
+            [(structures, 'structure', Bcfg2.Server.Plugin.StructurePlugin,
+              self.structures),
+             (generators, 'generator', Bcfg2.Server.Plugin.GeneratorPlugin,
+              self.generators)]:
+            for plugin in plug_names:
+                print plugin, self.plugins.keys(), plugin in self.plugins
+                raw_input()
+                if plugin in self.plugins:
+                    if not isinstance(self.plugins[plugin], plug_type):
+                        logger.error("Plugin %s is not a %s plugin; unloading" \
+                                 % (plugin, plug_tname))
+                        del self.plugins[plugin]
+                    else:
+                        collection.append(self.plugins[plugin])
+                else:
+                    logger.error("Plugin %s not loaded. Not enabled as a %s" \
+                                 % (plugin, plug_tname))
                     
     def GetStructures(self, metadata):
         '''Get all structures for client specified by metadata'''
diff --git a/src/lib/Server/Plugin.py b/src/lib/Server/Plugin.py
index 8c81e5839..6b308d1f7 100644
--- a/src/lib/Server/Plugin.py
+++ b/src/lib/Server/Plugin.py
@@ -39,6 +39,7 @@ class Plugin(object):
     __version__ = '$Id$'
     __author__ = 'bcfg-dev@mcs.anl.gov'
     __rmi__ = []
+    experimental = False
 
     def __init__(self, core, datastore):
         object.__init__(self)
@@ -47,18 +48,8 @@ class Plugin(object):
         self.data = "%s/%s" % (datastore, self.__name__)
         self.logger = logging.getLogger('Bcfg2.Plugins.%s' % (self.__name__))
 
-    def BuildStructures(self, _):
-        '''Build a set of structures tailored to the client metadata'''
-        return []
-
-    def GetProbes(self, _):
-        '''Return a set of probes for execution on client'''
-        return []
-
-    def ReceiveData(self, _, dummy):
-        '''Receive probe results pertaining to client'''
-        pass
-
+class GeneratorPlugin(Plugin):
+    '''Generator plugins contribute to literal client configurations'''
     def HandlesEntry(self, entry):
         '''This is the slow path method for routing configuration binding requests'''
         return False
@@ -80,6 +71,26 @@ class Plugin(object):
         # not implemented yet
         pass
 
+class StructurePlugin(Plugin):
+    '''Structure Plugins contribute to abstract client configurations'''
+    def BuildStructures(self, metadata):
+        '''return a list of abstract goal structures for client'''
+        raise PluginExecutionError
+
+class MetadataPlugin(Plugin):
+    '''Signal metadata capabilities for this plugin'''
+    pass
+
+class ProbingPlugin(Plugin):
+    '''Signal probe capability for this plugin'''
+    def GetProbes(self, _):
+        '''Return a set of probes for execution on client'''
+        return []
+
+    def ReceiveData(self, _, dummy):
+        '''Receive probe results pertaining to client'''
+        pass
+
 # the rest of the file contains classes for coherent file caching
 
 class FileBacked(object):
@@ -331,7 +342,7 @@ class XMLDirectoryBacked(DirectoryBacked):
     '''Directorybacked for *.xml'''
     patterns = re.compile('.*\.xml')    
 
-class PrioDir(Plugin, XMLDirectoryBacked):
+class PrioDir(GeneratorPlugin, XMLDirectoryBacked):
     '''This is a generator that handles package assignments'''
     __name__ = 'PrioDir'
     __child__ = XMLSrc
@@ -602,7 +613,7 @@ class FakeProperties:
     def __init__(self):
         self.properties = lxml.etree.Element("Properties")
 
-class GroupSpool(Plugin):
+class GroupSpool(GeneratorPlugin):
     '''The TGenshi generator implements a templating mechanism for configuration files'''
     __name__ = 'GroupSpool'
     __version__ = '$Id$'
diff --git a/src/lib/Server/Plugins/Account.py b/src/lib/Server/Plugins/Account.py
index 8599c028a..8cab47b01 100644
--- a/src/lib/Server/Plugins/Account.py
+++ b/src/lib/Server/Plugins/Account.py
@@ -3,7 +3,7 @@ __revision__ = '$Revision$'
 
 import Bcfg2.Server.Plugin
 
-class Account(Bcfg2.Server.Plugin.Plugin):
+class Account(Bcfg2.Server.Plugin.GeneratorPlugin):
     '''This module generates account config files,
     based on an internal data repo:
     static.(passwd|group|limits.conf) -> static entries
diff --git a/src/lib/Server/Plugins/Base.py b/src/lib/Server/Plugins/Base.py
index 2a849236f..3a06ba641 100644
--- a/src/lib/Server/Plugins/Base.py
+++ b/src/lib/Server/Plugins/Base.py
@@ -5,7 +5,8 @@ import Bcfg2.Server.Plugin
 import copy
 import lxml.etree
 
-class Base(Bcfg2.Server.Plugin.Plugin, Bcfg2.Server.Plugin.XMLDirectoryBacked):
+class Base(Bcfg2.Server.Plugin.StructurePlugin,
+           Bcfg2.Server.Plugin.XMLDirectoryBacked):
     '''This Structure is good for the pile of independent configs needed for most actual systems'''
     __name__ =  'Base'
     __version__ = '$Id$'
diff --git a/src/lib/Server/Plugins/Bundler.py b/src/lib/Server/Plugins/Bundler.py
index 597421699..f771d4016 100644
--- a/src/lib/Server/Plugins/Bundler.py
+++ b/src/lib/Server/Plugins/Bundler.py
@@ -3,7 +3,8 @@ __revision__ = '$Revision$'
 
 import copy, lxml.etree, Bcfg2.Server.Plugin
 
-class Bundler(Bcfg2.Server.Plugin.Plugin, Bcfg2.Server.Plugin.XMLDirectoryBacked):
+class Bundler(Bcfg2.Server.Plugin.StructurePlugin,
+              Bcfg2.Server.Plugin.XMLDirectoryBacked):
     '''The bundler creates dependent clauses based on the bundle/translation scheme from bcfg1'''
     __name__ =  'Bundler'
     __version__ = '$Id$'
diff --git a/src/lib/Server/Plugins/Hostbase.py b/src/lib/Server/Plugins/Hostbase.py
index dcd77f16a..05840f218 100644
--- a/src/lib/Server/Plugins/Hostbase.py
+++ b/src/lib/Server/Plugins/Hostbase.py
@@ -5,7 +5,7 @@ import sys, os
 os.environ['DJANGO_SETTINGS_MODULE'] = 'Bcfg2.Server.Hostbase.settings'
 from lxml.etree import Element, SubElement
 from syslog import syslog, LOG_INFO
-from Bcfg2.Server.Plugin import Plugin, PluginExecutionError, PluginInitError, DirectoryBacked
+from Bcfg2.Server.Plugin import StructurePlugin, PluginExecutionError, PluginInitError, DirectoryBacked
 from time import strftime
 from sets import Set
 from django.template import Context, loader
@@ -37,7 +37,7 @@ import cStringIO
 ##         '''This function is called when underlying data has changed'''
 ##         pass
     
-class Hostbase(Plugin):
+class Hostbase(StructurePlugin):
     '''The Hostbase plugin handles host/network info'''
     __name__ = 'Hostbase'
     __version__ = '$Id$'
diff --git a/src/lib/Server/Plugins/Metadata.py b/src/lib/Server/Plugins/Metadata.py
index b24dd0c66..f79aa4d03 100644
--- a/src/lib/Server/Plugins/Metadata.py
+++ b/src/lib/Server/Plugins/Metadata.py
@@ -74,7 +74,8 @@ class ProbeSet(Bcfg2.Server.Plugin.EntrySet):
         return ret
 
 
-class Metadata(Bcfg2.Server.Plugin.Plugin):
+class Metadata(Bcfg2.Server.Plugin.MetadataPlugin,
+               Bcfg2.Server.Plugin.ProbingPlugin):
     '''This class contains data for bcfg2 server metadata'''
     __version__ = '$Id$'
     __author__ = 'bcfg-dev@mcs.anl.gov'
diff --git a/src/lib/Server/Plugins/SGenshi.py b/src/lib/Server/Plugins/SGenshi.py
index 10559733c..bf063b884 100644
--- a/src/lib/Server/Plugins/SGenshi.py
+++ b/src/lib/Server/Plugins/SGenshi.py
@@ -44,7 +44,7 @@ class SGenshiEntrySet(Bcfg2.Server.Plugin.EntrySet):
                 logger.error("SGenshi: Failed to template file %s" % entry.name)
         return ret
 
-class SGenshi(SGenshiEntrySet, Bcfg2.Server.Plugin.Plugin):
+class SGenshi(SGenshiEntrySet, Bcfg2.Server.Plugin.StructurePlugin):
     '''The SGenshi plugin provides templated structures'''
     __name__ = 'SGenshi'
     __version__ = '$Id$'
diff --git a/src/lib/Server/Plugins/SSHbase.py b/src/lib/Server/Plugins/SSHbase.py
index 005b52988..cdd95181b 100644
--- a/src/lib/Server/Plugins/SSHbase.py
+++ b/src/lib/Server/Plugins/SSHbase.py
@@ -4,7 +4,7 @@ __revision__ = '$Revision$'
 import binascii, os, socket
 import Bcfg2.Server.Plugin
 
-class SSHbase(Bcfg2.Server.Plugin.Plugin,  Bcfg2.Server.Plugin.DirectoryBacked):
+class SSHbase(Bcfg2.Server.Plugin.GeneratorPlugin,  Bcfg2.Server.Plugin.DirectoryBacked):
     '''The sshbase generator manages ssh host keys (both v1 and v2)
     for hosts.  It also manages the ssh_known_hosts file. It can
     integrate host keys from other management domains and similarly
diff --git a/src/lib/Server/Plugins/Vhost.py b/src/lib/Server/Plugins/Vhost.py
deleted file mode 100644
index 5c38cd19e..000000000
--- a/src/lib/Server/Plugins/Vhost.py
+++ /dev/null
@@ -1,116 +0,0 @@
-'''
-#-------------------------------------------
-# Script Name: vhost.py 
-# Script Version: 1.0
-# Date: 20 July 2005
-# Author: Scott R Behrens
-# Description: opens a request file, genereates a vhost httpd.conf file, and establishes symlinks
-# Revision History:
-#    1.0/<20-7-2005>: orignal version
-#    1.1/<20-7-2005>: now genreates multiple files based on XML document 
-#    1.2/<20-8-2005>: generates one file encoded in base64
-#    1.3/<06-9-2005>: cleanup some pylint and style problems
-#-------------------------------------------
-'''
-__revision__ = '$Revision$'
-
-import base64
-from copy import deepcopy
-from lxml.etree import XML, Element, SubElement
-from socket import gethostbyname
-from Bcfg2.Server.Plugin import Plugin, PluginExecutionError, SingleXMLFileBacked
-
-class VhostFile(SingleXMLFileBacked):
-    '''The Vhost file contains webserver vhost configuration elements'''
-    sitesen = "/etc/apache2/sites-enabled/"
-    sitesav = "/etc/apache2/sites-available/"
-
-    def __init__(self, name, fam):
-        self.meta = Element('dummy')
-        self.dispatch = {'ConfigFile':{'/etc/default/apache2':self.generateApacheDefault},
-                         'Service':{'apache2':self.generateApacheSvc}}
-        SingleXMLFileBacked.__init__(self, name, fam)
-        self.http = open('/disks/bcfg2/Vhost/default.httpd', 'r').readlines()
-        self.servers = []
-        self.vhosts = {}
-
-
-    def Index(self):
-        '''Build vhost data structures'''
-        self.meta = XML(self.data)
-        self.servers = [serv.get('name') for serv in self.meta.findall('server')]
-        self.vhosts = {}
-        for server in self.meta.findall("server"):
-            for vhost in server.findall("vhost"):
-                name = vhost.get('name')
-                self.dispatch[self.sitesav + name] = self.generateSiteFile
-                self.vhosts[name] = vhost
-
-    def BuildStructures(self, metadata):
-        '''Build apache+vhost bundle'''
-        if metadata.hostname not in self.servers:
-            return []
-        output = Element("Bundle", name='apache-vhost', version='2.0')
-        for server in self.meta.findall("server"):
-            if server.attrib['name'] in metadata.hostname:
-                for vhost in server.findall("vhost"):
-                    name = vhost.get('name')
-                    SubElement(output, "SymLink", name=self.sitesen+name, to=self.sitesav+name)
-                    SubElement(output, "ConfigFile", name="/etc/apache2/sites-available/" + name)
-                    SubElement(output, "ConfigFile", name='/etc/default/apache2')
-                    for software in self.meta.findall("Software"):
-                        for child in software.getchildren():
-                            output.append(deepcopy(child))
-        return [output]
-
-    def generateApacheDefault(self, entry, metadata):
-        '''Build /etc/default/apache2'''
-        if metadata.hostname in self.servers:
-            entry.text = 'NO_START=0\n'
-        else:
-            entry.text = 'NO_START=1\n'
-        perms = {'owner':'root', 'group':'root', 'perms':'0644'}
-        [entry.attrib.__setitem__(key, value) for (key, value) in perms.iteritems()]
-		
-    def generateApacheSvc(self, entry, metadata):
-        '''Enable apache service on webservices, disable on others'''
-        if metadata.hostname in self.servers:
-            entry.set('status', 'on')
-        else:
-            entry.set('status', 'off')
-
-    def generateSiteFile(self, entry, metadata):
-        '''Build site-specific config file for vhost'''
-        if metadata.hostname not in self.servers:
-            raise PluginExecutionError
-        vhostname = entry.get('name')[len(self.sitesav):]
-        if not self.vhosts.has_key(vhostname):
-            raise PluginExecutionError
-
-        if self.vhosts[vhostname].get('root') == "Hostname":
-            choice = vhostname
-        else:
-            choice = gethostbyname(vhostname) 
-
-        config = ""
-        for line in self.http:
-            line = line.replace("XXemailXX", self.vhosts[vhostname].get('email'))
-            line = line.replace("XXdomainXX", vhostname)
-            line = line.replace("XXchoiceXX", choice)
-            config += line
-        entry.text = base64.encodestring(config)
-        perms = {'owner':'root', 'group':'root', 'perms':'0644', 'encoding':'base64'}
-        [entry.attrib.__setitem__(key, value) for (key, value) in perms.iteritems()]
-
-class Vhost(Plugin):
-    '''This Structure is good for the pile of independent configs needed for most actual systems'''
-    __name__ =  'Vhost'
-    __version__ = '$Id$'
-    __author__ = 'behrens@mcs.anl.gov'
-
-    '''Vhost creates independent clauses based on client metadata'''
-    def __init__(self, core, datastore):
-        Plugin.__init__(self, core, datastore)
-        self.Vhost = VhostFile("%s/Vhost/Vhost.xml"%(datastore), self.core.fam)
-        self.BuildStructures = self.Vhost.BuildStructures
-        self.Entries = self.Vhost.dispatch
diff --git a/src/sbin/bcfg2-server b/src/sbin/bcfg2-server
index 09d2ce619..6cffd2253 100755
--- a/src/sbin/bcfg2-server
+++ b/src/sbin/bcfg2-server
@@ -100,7 +100,8 @@ class Bcfg2Serv(Bcfg2.Component.Component):
             name = self.Core.metadata.resolve_client(address)
             meta = self.Core.metadata.get_metadata(name)
             
-            for plugin in self.Core.plugins.values():
+            for plugin in [p for p in self.Core.plugins.values() \
+                           if isinstance(p, Bcfg2.Server.Plugin.ProbingPlugin)]:
                 for probe in plugin.GetProbes(meta):
                     resp.append(probe)
             return tostring(resp)