Add basic dependency processing code

 * To enable, add a Deps directory and enable the Deps plugin
 * schema validation works
 * prerequisites are automatically added to configurations


git-svn-id: https://svn.mcs.anl.gov/repos/bcfg/trunk/bcfg2@1924 ce84e21b-d406-0410-9b95-82705330c041

3 files changed, 99 insertions, 1 deletions

diff --git a/src/lib/Server/Core.py b/src/lib/Server/Core.py
index e417f9aa0..6f11e83e7 100644
--- a/src/lib/Server/Core.py
+++ b/src/lib/Server/Core.py
@@ -293,6 +293,11 @@ class Core(object):
         except:
             logger.error("error in GetStructures", exc_info=1)
             return lxml.etree.Element("error", type='structure error')
+
+        if self.plugins.has_key('Deps'):
+            # do prereq processing
+            prereqs = self.plugins['Deps'].GeneratePrereqs(structures, meta)
+            structures.append(prereqs)
         
         for astruct in structures:
             try:
diff --git a/src/lib/Server/Plugins/Deps.py b/src/lib/Server/Plugins/Deps.py
new file mode 100644
index 000000000..945c53e70
--- /dev/null
+++ b/src/lib/Server/Plugins/Deps.py
@@ -0,0 +1,92 @@
+'''This plugin provides automatic dependency handling'''
+__revision__ = '$Revision:$'
+
+import Bcfg2.Server.Plugin, lxml.etree
+
+class DNode(Bcfg2.Server.Plugin.INode):
+    '''DNode provides supports for single predicate types for dependencies'''
+    raw = {'Group':"lambda x:'%s' in x.groups and predicate(x)"}
+    containers = ['Group']
+    
+    def __init__(self, data, idict, parent=None):
+        self.data = data
+        self.contents = {}
+        if parent == None:
+            self.predicate = lambda x:True
+        else:
+            predicate = parent.predicate
+            if data.tag in self.raw.keys():
+                self.predicate = eval(self.raw[data.tag] % (data.get('name')), {'predicate':predicate})
+            else:
+                raise Exception
+        mytype = self.__class__
+        self.children = []
+        for item in data.getchildren():
+            if item.tag in self.containers:
+                self.children.append(mytype(item, idict, self))
+            else:
+                data = [(child.tag, child.get('name')) for child in item.getchildren()]
+                try:
+                    self.contents[item.tag][item.get('name')] = data
+                except KeyError:
+                    self.contents[item.tag] = {item.get('name'):data}
+
+class DepXMLSrc(Bcfg2.Server.Plugin.XMLSrc):
+    __node__ = DNode
+
+class Deps(Bcfg2.Server.Plugin.PrioDir):
+    __name__ = 'Deps'
+    __version__ = '$Id:$'
+    __author__ = 'bcfg-dev@mcs.anl.gov'
+    __child__ = DepXMLSrc
+
+    def __init__(self, core, datastore):
+        Bcfg2.Server.Plugin.PrioDir.__init__(self, core, datastore)
+        self.cache = {}
+
+    def HandleEvent(self, event):
+        self.cache = {}
+        Bcfg2.Server.Plugin.PrioDir.HandleEvent(self, event)
+        
+    def GeneratePrereqs(self, structures, metadata):
+        entries = []
+        prereqs = []
+        for structure in structures:
+            for entry in structure.getchildren():
+                if (entry.tag, entry.get('name')) not in entries:
+                    entries.append((entry.tag, entry.get('name')))
+        entries.sort()
+        entries = tuple(entries)
+        gdata = metadata.groups[:]
+        gdata.sort()
+        gdata = tuple(gdata)
+        if self.cache.has_key((entries, gdata)):
+            prereqs = self.cache[(entries, gdata)]
+        else:
+            [src.Cache(metadata) for src in self.entries.values()]
+            
+            for entry in entries:
+                matching = [src for src in self.entries.values()
+                            if src.cache and src.cache[1].has_key(entry[0])
+                            and src.cache[1][entry[0]].has_key(entry[1])]
+                if len(matching) > 1:
+                    prio = [int(src.priority) for src in matching]
+                    if prio.count(max(prio)) > 1:
+                        self.logger.error("Found conflicting %s sources with same priority for %s, pkg %s" %
+                                          (entry[0].lower(), metadata.hostname, entry[1]))
+                        raise PluginExecutionError
+                    index = prio.index(max(prio))
+                    matching = [matching[index]]
+
+                if not matching:
+                    continue
+                elif len(matching) == 1:
+                    for prq in src.cache[1][entry[0]][entry[1]]:
+                        if prq not in prereqs:
+                            prereqs.append(prq)
+            self.cache[(entries, gdata)] = prereqs
+            
+        newstruct = lxml.etree.Element("Independant")
+        for tag, name in prereqs:
+            lxml.etree.SubElement(newstruct, tag, name=name)
+        return newstruct
diff --git a/src/sbin/bcfg2-repo-validate b/src/sbin/bcfg2-repo-validate
index 2ec7a20b4..360dbf45f 100644
--- a/src/sbin/bcfg2-repo-validate
+++ b/src/sbin/bcfg2-repo-validate
@@ -31,7 +31,8 @@ if __name__ == '__main__':
                 'base':("%s/Base/*.xml", "%s/base.xsd"),
                 'base':("%s/Rules/*.xml", "%s/rules.xsd"),
                 'imageinfo':("%s/etc/reports.xml", "%s/report-configuration.xsd"),
-                'services':("%s/Svcmgr/*.xml", "%s/services.xsd")}
+                'services':("%s/Svcmgr/*.xml", "%s/services.xsd"),
+                'deps':("%s/Deps/*.xml", "%s/deps.xsd")}
 
     failures  = 0
     for k, (spec, schemaname) in filesets.iteritems():