Allow to run directly from a git checkout (#1037)

Signed-off-by: Sol Jerome <sol.jerome@gmail.com>

1 files changed, 230 insertions, 0 deletions

diff --git a/src/lib/Bcfg2/Server/Plugins/FileProbes.py b/src/lib/Bcfg2/Server/Plugins/FileProbes.py
new file mode 100644
index 000000000..5beec7be0
--- /dev/null
+++ b/src/lib/Bcfg2/Server/Plugins/FileProbes.py
@@ -0,0 +1,230 @@
+""" This module allows you to probe a client for a file, which is then
+added to the specification.  On subsequent runs, the file will be
+replaced on the client if it is missing; if it has changed on the
+client, it can either be updated in the specification or replaced on
+the client """
+
+import os
+import sys
+import errno
+import binascii
+import lxml.etree
+import Bcfg2.Options
+import Bcfg2.Server.Plugin
+
+probecode = """#!/usr/bin/env python
+
+import os
+import pwd
+import grp
+import binascii
+import lxml.etree
+
+path = "%s"
+
+if not os.path.exists(path):
+    print "%%s does not exist" %% path
+    raise SystemExit(1)
+
+stat = os.stat(path)
+data = lxml.etree.Element("ProbedFileData",
+                          name=path,
+                          owner=pwd.getpwuid(stat[4])[0],
+                          group=grp.getgrgid(stat[5])[0],
+                          perms=oct(stat[0] & 07777))
+data.text = binascii.b2a_base64(open(path).read())
+print lxml.etree.tostring(data)
+"""
+
+class FileProbesConfig(Bcfg2.Server.Plugin.SingleXMLFileBacked,
+                       Bcfg2.Server.Plugin.StructFile):
+    """ Config file handler for FileProbes """
+    def __init__(self, filename, fam):
+        Bcfg2.Server.Plugin.SingleXMLFileBacked.__init__(self, filename, fam)
+        Bcfg2.Server.Plugin.StructFile.__init__(self, filename)
+
+
+class FileProbes(Bcfg2.Server.Plugin.Plugin,
+                 Bcfg2.Server.Plugin.Probing):
+    """ This module allows you to probe a client for a file, which is then
+    added to the specification.  On subsequent runs, the file will be
+    replaced on the client if it is missing; if it has changed on the
+    client, it can either be updated in the specification or replaced on
+    the client """
+
+    name = 'FileProbes'
+    experimental = True
+    __author__ = 'chris.a.st.pierre@gmail.com'
+
+    def __init__(self, core, datastore):
+        Bcfg2.Server.Plugin.Plugin.__init__(self, core, datastore)
+        Bcfg2.Server.Plugin.Probing.__init__(self)
+        self.config = FileProbesConfig(os.path.join(self.data, 'config.xml'),
+                                       core.fam)
+        self.entries = dict()
+        self.probes = dict()
+
+    def GetProbes(self, metadata):
+        """Return a set of probes for execution on client."""
+        if metadata.hostname not in self.probes:
+            cfg = self.core.plugins['Cfg']
+            self.entries[metadata.hostname] = dict()
+            self.probes[metadata.hostname] = []
+            for entry in self.config.Match(metadata):
+                path = entry.get("name")
+                # do not probe for files that are already in Cfg and
+                # for which update is false; we can't possibly do
+                # anything with the data we get from such a probe
+                try:
+                    if (entry.get('update', 'false').lower() == "false" and
+                        cfg.entries[path].get_pertinent_entries(entry,
+                                                                metadata)):
+                        continue
+                except (KeyError, Bcfg2.Server.Plugin.PluginExecutionError):
+                    pass
+                self.entries[metadata.hostname][path] = entry
+                probe = lxml.etree.Element('probe', name=path,
+                                           source=self.name,
+                                           interpreter="/usr/bin/env python")
+                probe.text = probecode % path
+                self.probes[metadata.hostname].append(probe)
+                self.debug_log("Adding file probe for %s to %s" %
+                               (path, metadata.hostname))
+        return self.probes[metadata.hostname]
+
+    def ReceiveData(self, metadata, datalist):
+        """Receive data from probe."""
+        self.debug_log("Receiving file probe data from %s" % metadata.hostname)
+
+        for data in datalist:
+            if data.text is None:
+                self.logger.error("Got null response to %s file probe from %s" %
+                                  (data.get('name'), metadata.hostname))
+            else:
+                try:
+                    self.write_data(lxml.etree.XML(data.text), metadata)
+                except lxml.etree.XMLSyntaxError:
+                    # if we didn't get XML back from the probe, assume
+                    # it's an error message
+                    self.logger.error(data.text)
+
+    def write_data(self, data, metadata):
+        """Write the probed file data to the bcfg2 specification."""
+        filename = data.get("name")
+        contents = binascii.a2b_base64(data.text)
+        entry = self.entries[metadata.hostname][filename]
+        cfg = self.core.plugins['Cfg']
+        specific = "%s.H_%s" % (os.path.basename(filename), metadata.hostname)
+        # we can't use os.path.join() for this because specific
+        # already has a leading /, which confuses os.path.join()
+        fileloc = "%s%s" % (cfg.data, os.path.join(filename, specific))
+
+        create = False
+        try:
+            cfg.entries[filename].bind_entry(entry, metadata)
+        except Bcfg2.Server.Plugin.PluginExecutionError:
+            create = True
+
+        # get current entry data
+        if entry.text and entry.get("encoding") == "base64":
+            entrydata = binascii.a2b_base64(entry.text)
+        else:
+            entrydata = entry.text
+
+        if create:
+            self.logger.info("Writing new probed file %s" % fileloc)
+            self.write_file(fileloc, contents)
+            self.verify_file(filename, contents, metadata)
+            infoxml = os.path.join("%s%s" % (cfg.data, filename), "info.xml")
+            self.write_infoxml(infoxml, entry, data)
+        elif entrydata == contents:
+            self.debug_log("Existing %s contents match probed contents" %
+                           filename)
+            return
+        elif (entry.get('update', 'false').lower() == "true"):
+            self.logger.info("Writing updated probed file %s" % fileloc)
+            self.write_file(fileloc, contents)
+            self.verify_file(filename, contents, metadata)
+        else:
+            self.logger.info("Skipping updated probed file %s" % fileloc)
+            return
+
+    def write_file(self, fileloc, contents):
+        try:
+            os.makedirs(os.path.dirname(fileloc))
+        except OSError:
+            err = sys.exc_info()[1]
+            if err.errno == errno.EEXIST:
+                pass
+            else:
+                self.logger.error("Could not create parent directories for %s: "
+                                  "%s" % (fileloc, err))
+                return
+
+        try:
+            open(fileloc, 'wb').write(contents)
+        except IOError:
+            err = sys.exc_info()[1]
+            self.logger.error("Could not write %s: %s" % (fileloc, err))
+            return
+
+    def verify_file(self, filename, contents, metadata):
+        # Service the FAM events queued up by the key generation so
+        # the data structure entries will be available for binding.
+        #
+        # NOTE: We wait for up to ten seconds. There is some potential
+        # for race condition, because if the file monitor doesn't get
+        # notified about the new key files in time, those entries
+        # won't be available for binding. In practice, this seems
+        # "good enough".
+        entry = self.entries[metadata.hostname][filename]
+        cfg = self.core.plugins['Cfg']
+        tries = 0
+        updated = False
+        while not updated:
+            if tries >= 10:
+                self.logger.error("%s still not registered" % filename)
+                return
+            self.core.fam.handle_events_in_interval(1)
+            try:
+                cfg.entries[filename].bind_entry(entry, metadata)
+            except Bcfg2.Server.Plugin.PluginExecutionError:
+                tries += 1
+                continue
+
+            # get current entry data
+            if entry.get("encoding") == "base64":
+                entrydata = binascii.a2b_base64(entry.text)
+            else:
+                entrydata = entry.text
+            if entrydata == contents:
+                updated = True
+            tries += 1
+
+    def write_infoxml(self, infoxml, entry, data):
+        """ write an info.xml for the file """
+        if os.path.exists(infoxml):
+            return
+
+        self.logger.info("Writing info.xml at %s for %s" %
+                         (infoxml, data.get("name")))
+        info = \
+            lxml.etree.Element("Info",
+                               owner=data.get("owner",
+                                              Bcfg2.Options.MDATA_OWNER.value),
+                               group=data.get("group",
+                                              Bcfg2.Options.MDATA_GROUP.value),
+                               perms=data.get("perms",
+                                              Bcfg2.Options.MDATA_PERMS.value),
+                               encoding=entry.get("encoding",
+                                                  Bcfg2.Options.ENCODING.value))
+
+        root = lxml.etree.Element("FileInfo")
+        root.append(info)
+        try:
+            open(infoxml, "w").write(lxml.etree.tostring(root,
+                                                         pretty_print=True))
+        except IOError:
+            err = sys.exc_info()[1]
+            self.logger.error("Could not write %s: %s" % (fileloc, err))
+            return