diff options
| -rw-r--r-- | doc/server/plugins/probes/index.txt | 43 | ||||
| -rw-r--r-- | src/lib/Server/Plugins/Probes.py | 93 |
2 files changed, 126 insertions, 10 deletions
diff --git a/doc/server/plugins/probes/index.txt b/doc/server/plugins/probes/index.txt index b9f698a0f..d52e7bb95 100644 --- a/doc/server/plugins/probes/index.txt +++ b/doc/server/plugins/probes/index.txt @@ -85,10 +85,12 @@ file looks like:: #end if Any Probe script you run will store its output in -``$self.metadata.Probes["scriptname"]``, so we get to our `scratchlocal` -script's output as seen above. Note that we had to wrap the output in an -`int()` call; the script output is treated as a string, so it needs to -be converted before it can be tested numerically. +``$self.metadata.Probes["scriptname"]``, so we get to our +`scratchlocal` script's output as seen above. (See `Handling Probe +Output`_, below, for more information on how this is done.) Note that +we had to wrap the output in an `int()` call; the script output is +treated as a string, so it needs to be converted before it can be +tested numerically. With all of these pieces in place, the following series of events will happen when the client is run: @@ -110,8 +112,37 @@ is to add the ``/etc/auto.master`` to a Bundle: <Path name='/etc/auto.master'/> -Host and Group Specific probes -============================== +Handling Probe Output +===================== + +Bcfg2 stores output from probes in the ``Probes`` property of a +client's metadata object. To access this data in TGenshi, for +instance, you could do:: + + ${metadata.Probes['script-name']} + +This is not the full output of the probe; any lines that start with +"group:" have been stripped from the output. The data is a +string-like object that has some interesting and salient features: + +* If the data is a valid XML document, then + ``metadata.Probes['script-name'].xdata`` will be an + ``lxml.etree._Element`` object representing the XML data. +* If the data is a valid JSON document, and the Python ``json`` module + is installed (included in Python 2.6 onward), then + ``metadata.Probes['script-name'].json`` will be a data structure + representing the JSON data. +* If the data is a valid YAML document, and either the Python ``yaml`` + module or ``syck`` module is installed, then + ``metadata.Probes['script-name'].yaml`` will be a data structure + representing the YAML data. + +If these conditions are not met, then the named properties will be +``None``. In all other fashions, the probe data objects should act +like strings. + +Host- and Group-Specific probes +=============================== Bcfg2 has the ability to alter probes based on client hostname and group membership. These files work similarly to files in Cfg. diff --git a/src/lib/Server/Plugins/Probes.py b/src/lib/Server/Plugins/Probes.py index 3599f2af1..4a7171297 100644 --- a/src/lib/Server/Plugins/Probes.py +++ b/src/lib/Server/Plugins/Probes.py @@ -2,12 +2,96 @@ import lxml.etree import operator import re +try: + import json + has_json = True +except ImportError: + has_json = False + +try: + import syck + has_syck = True +except ImportError: + has_syck = False + +try: + import yaml + has_yaml = True +except ImportError: + has_yaml = False + import Bcfg2.Server.Plugin specific_probe_matcher = re.compile("(.*/)?(?P<basename>\S+)(.(?P<mode>[GH](\d\d)?)_\S+)") probe_matcher = re.compile("(.*/)?(?P<basename>\S+)") +class ProbeData (object): + """ a ProbeData object emulates a str object, but also has .xdata + and .json properties to provide convenient ways to use ProbeData + objects as XML or JSON data """ + def __init__(self, data): + self.data = data + self._xdata = None + self._json = None + self._yaml = None + + def __str__(self): + return str(self.data) + + def __repr__(self): + return repr(self.data) + + def __getattr__(self, name): + """ make ProbeData act like a str object """ + return getattr(self.data, name) + + def __complex__(self): + return complex(self.data) + + def __int__(self): + return int(self.data) + + def __long__(self): + return long(self.data) + + def __float__(self): + return float(self.data) + + @property + def xdata(self): + if self._xdata is None: + try: + self._xdata = lxml.etree.XML(self.data) + except lxml.etree.XMLSyntaxError: + pass + return self._xdata + + @property + def json(self): + if self._json is None and has_json: + try: + self._json = json.loads(self.data) + except ValueError: + pass + return self._json + + @property + def yaml(self): + if self._yaml is None: + if has_yaml: + try: + self._yaml = yaml.load(self.data) + except yaml.YAMLError: + pass + elif has_syck: + try: + self._yaml = syck.load(self.data) + except syck.error: + pass + return self._yaml + + class ProbeSet(Bcfg2.Server.Plugin.EntrySet): ignore = re.compile("^(\.#.*|.*~|\\..*\\.(tmp|sw[px])|probed\\.xml)$") @@ -106,7 +190,8 @@ class Probes(Bcfg2.Server.Plugin.Plugin, self.cgroups[client.get('name')] = [] for pdata in client: if (pdata.tag == 'Probe'): - self.probedata[client.get('name')][pdata.get('name')] = pdata.get('value') + self.probedata[client.get('name')][pdata.get('name')] = \ + ProbeData(pdata.get('value')) elif (pdata.tag == 'Group'): self.cgroups[client.get('name')].append(pdata.get('name')) @@ -142,11 +227,11 @@ class Probes(Bcfg2.Server.Plugin.Plugin, if newgroup not in self.cgroups[client.hostname]: self.cgroups[client.hostname].append(newgroup) dlines.remove(line) - dtext = "\n".join(dlines) + dobj = ProbeData("\n".join(dlines)) try: - self.probedata[client.hostname].update({data.get('name'): dtext}) + self.probedata[client.hostname].update({data.get('name'): dobj}) except KeyError: - self.probedata[client.hostname] = {data.get('name'): dtext} + self.probedata[client.hostname] = {data.get('name'): dobj} def get_additional_groups(self, meta): return self.cgroups.get(meta.hostname, list()) |