summaryrefslogtreecommitdiffstats
path: root/src/lib/Server/Core.py
blob: e25bec4b280855f8bf521e652f97bb037e0bb187 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
'''Bcfg2.Server.Core provides the runtime support for bcfg2 modules'''
__revision__ = '$Revision$'

from time import time

from Bcfg2.Server.Plugin import PluginInitError, PluginExecutionError
import Bcfg2.Server.FileMonitor

import logging, lxml.etree, os
import Bcfg2.Server.Plugins.Metadata

logger = logging.getLogger('Bcfg2.Core')

try:
    import psyco
    psyco.full()
except:
    pass

class CoreInitError(Exception):
    '''This error is raised when the core cannot be initialized'''
    pass

class Core(object):
    '''The Core object is the container for all Bcfg2 Server logic, and modules'''

    def __init__(self, repo, plugins, structures, generators, password, svn,
                 encoding, filemonitor='default'):
        object.__init__(self)
        self.datastore = repo
        if filemonitor not in Bcfg2.Server.FileMonitor.available:
            logger.error("File monitor driver %s not available; forcing to default" % filemonitor)
            filemonitor = 'default'
        try:
            self.fam = Bcfg2.Server.FileMonitor.available[filemonitor]()
        except IOError:
            raise CoreInitError, "failed to instantiate fam driver (used %s)" % \
                  filemonitor
        self.pubspace = {}
        self.generators = []
        self.structures = []
        self.cron = {}
        self.plugins = {}
        self.revision = '-1'
        self.password = password
        self.svn = svn
        self.encoding = encoding
        try:
            if self.svn:
                self.read_svn_revision()
        except:
            self.svn = False

        [data.remove('') for data in [plugins, structures, generators] if '' in data]
        
        
        for plugin in structures + generators + plugins:
                if not plugin in self.plugins:
                    self.init_plugins(plugin)    

        chk_plugins = self.plugins.values()
        while True:
            try:
                plugin = chk_plugins.pop()
                if isinstance(plugin, Bcfg2.Server.Plugin.MetadataPlugin):
                    self.metadata = plugin
                    break
            except:
                pass
            if not chk_plugins:
                self.init_plugins("Metadata")
                self.metadata = self.plugins["Metadata"]
                break

        chk_plugins = self.plugins.values()
        while True:
            try:
                plugin = chk_plugins.pop()
                if isinstance(plugin, Bcfg2.Server.Plugin.StatisticsPlugin):
                    self.stats = plugin
                    break
            except:
                pass
            if not chk_plugins:
                self.init_plugins("Statistics")
                self.stats = self.plugins["Statistics"]
                break

        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:
                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 init_plugins(self, plugin):
        try:
            mod = getattr(__import__("Bcfg2.Server.Plugins.%s" %
                                (plugin)).Server.Plugins, plugin)
        except ImportError, e:
            logger.error("Failed to load plugin %s: %s" % (plugin, e))
            return
        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] = 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)    
            
    def GetStructures(self, metadata):
        '''Get all structures for client specified by metadata'''
        return reduce(lambda x, y:x+y,
                      [struct.BuildStructures(metadata) for struct in self.structures], [])

    def BindStructure(self, structure, metadata):
        '''Bind a complete structure'''
        for entry in structure.getchildren():
            if entry.tag.startswith("Bound"):
                entry.tag = entry.tag[5:]
                continue
            try:
                self.Bind(entry, metadata)
            except PluginExecutionError:
                logger.error("Failed to bind entry: %s %s" %  (entry.tag, entry.get('name')))
            except:
                logger.error("Unexpected failure in BindStructure: %s %s" % (entry.tag, entry.get('name')),
                             exc_info=1)

    def Bind(self, entry, metadata):
        '''Bind an entry using the appropriate generator'''
        if 'altsrc' in entry.attrib:
            oldname = entry.get('name')
            entry.set('name', entry.get('altsrc'))
            entry.set('realname', oldname)
            del entry.attrib['altsrc']
            try:
                ret = self.Bind(entry, metadata)
                entry.set('name', oldname)
                del entry.attrib['realname']
                return ret
            except:
                entry.set('name', oldname)
                logger.error("Failed binding entry %s:%s with altsrc %s" \
                             % (entry.tag, entry.get('name'),
                                entry.get('altsrc')))
                logger.error("Falling back to %s:%s" % (entry.tag,
                                                        entry.get('name')))

        glist = [gen for gen in self.generators if
                 entry.get('name') in gen.Entries.get(entry.tag, {})]
        if len(glist) == 1:
            return glist[0].Entries[entry.tag][entry.get('name')](entry, metadata)
        elif len(glist) > 1:
            generators = ", ".join([gen.__name__ for gen in glist])
            logger.error("%s %s served by multiple generators: %s" % \
                         (entry.tag, entry.get('name'), generators))
        g2list = [gen for gen in self.generators if gen.HandlesEntry(entry)]
        if len(g2list) == 1:
            return g2list[0].HandleEntry(entry, metadata)
        raise PluginExecutionError, (entry.tag, entry.get('name'))
                
    def BuildConfiguration(self, client):
        '''Build Configuration for client'''
        start = time()
        config = lxml.etree.Element("Configuration", version='2.0', revision=self.revision)
        try:
            meta = self.metadata.get_metadata(client)
        except Bcfg2.Server.Plugins.Metadata.MetadataConsistencyError:
            logger.error("Metadata consistency error for client %s" % client)
            return lxml.etree.Element("error", type='metadata error')

        try:
            structures = self.GetStructures(meta)
        except:
            logger.error("error in GetStructures", exc_info=1)
            return lxml.etree.Element("error", type='structure error')

        if 'Deps' in self.plugins:
            # do prereq processing
            prereqs = self.plugins['Deps'].GeneratePrereqs(structures, meta)
            structures.append(prereqs)

        # Perform altsrc consistency checking
        esrcs = {}
        for struct in structures:
            for entry in struct:
                key = (entry.tag, entry.get('name'))
                if key in esrcs:
                    if esrcs[key] != entry.get('altsrc'):
                        logger.error("Found inconsistent altsrc mapping for entry %s:%s" % key)
                else:
                    esrcs[key] = entry.get('altsrc', None)
        del esrcs
        
        for astruct in structures:
            try:
                self.BindStructure(astruct, meta)
                config.append(astruct)
            except:
                logger.error("error in BindStructure", exc_info=1)
        logger.info("Generated config for %s in %s seconds"%(client, time() - start))
        return config

    def Service(self):
        '''Perform periodic update tasks'''
        count = self.fam.Service()
        if count and self.svn:
            self.read_svn_revision()
        try:
            self.stats.WriteBack()
        except:
            logger.error("error in Statistics", exc_info=1)
            
    def read_svn_revision(self):
        '''Read svn revision information for the bcfg2 repository'''
        try:
            data = os.popen("env LC_ALL=C svn info %s" % (self.datastore)).readlines()
            revline = [line.split(': ')[1].strip() for line in data if line[:9] == 'Revision:'][-1]
            self.revision = revline
        except IndexError:
            logger.error("Failed to read svn info; disabling svn support")
            logger.error('''Ran command "svn info %s"''' % (self.datastore))
            logger.error("Got output: %s" % data)
            self.svn = False

    def GetDecisions(self, metadata, mode):
        result = []
        for plugin in self.plugins.values():
            try:
                if isinstance(plugin, Bcfg2.Server.Plugin.DecisionPlugin):
                    result += plugin.GetDecisions(metadata, mode)
            except:
                logger.error("Plugin: %s failed to generate decision list" % plugin.__name__, exc_info=1)
        return result