diff options
Diffstat (limited to 'src/lib/Bcfg2/Server/Plugins/Cfg/CfgJinja2Generator.py')
-rw-r--r-- | src/lib/Bcfg2/Server/Plugins/Cfg/CfgJinja2Generator.py | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/src/lib/Bcfg2/Server/Plugins/Cfg/CfgJinja2Generator.py b/src/lib/Bcfg2/Server/Plugins/Cfg/CfgJinja2Generator.py new file mode 100644 index 000000000..cff9ff61e --- /dev/null +++ b/src/lib/Bcfg2/Server/Plugins/Cfg/CfgJinja2Generator.py @@ -0,0 +1,91 @@ +""" The CfgJinja2Generator allows you to use the `Jinja2 +<http://jinja.pocoo.org/>`_ templating system to generate +:ref:`server-plugins-generators-cfg` files. """ + +import os +import sys +import Bcfg2.Options +from Bcfg2.Server.Plugin import PluginExecutionError, \ + DefaultTemplateDataProvider, get_template_data +from Bcfg2.Server.Plugins.Cfg import CfgGenerator + +try: + from jinja2 import Environment, FileSystemLoader + HAS_JINJA2 = True +except ImportError: + HAS_JINJA2 = False + + +class RelEnvironment(Environment): + """Override join_path() to enable relative template paths.""" + def join_path(self, template, parent): + return os.path.join(os.path.dirname(parent), template) + + +class DefaultJinja2DataProvider(DefaultTemplateDataProvider): + """ Template data provider for Jinja2 templates. Jinja2 and + Genshi currently differ over the value of the ``path`` variable, + which is why this is necessary. """ + + def get_template_data(self, entry, metadata, template): + rv = DefaultTemplateDataProvider.get_template_data(self, entry, + metadata, template) + rv['path'] = rv['name'] + return rv + + +class CfgJinja2Generator(CfgGenerator): + """ The CfgJinja2Generator allows you to use the `Jinja2 + <http://jinja.pocoo.org/>`_ templating system to generate + :ref:`server-plugins-generators-cfg` files. """ + + #: Handle .jinja2 files + __extensions__ = ['jinja2'] + + #: ``__loader_cls__`` is the class that will be instantiated to + #: load the template files. It must implement one public function, + #: ``load()``, as :class:`genshi.template.TemplateLoader`. + __loader_cls__ = FileSystemLoader + + #: ``__environment_cls__`` is the class that will be instantiated to + #: store the jinja2 environment. It must implement one public function, + #: ``get_template()``, as :class:`jinja2.Environment`. + __environment_cls__ = RelEnvironment + + #: Ignore ``.jinja2_include`` files so they can be used with the + #: Jinja2 ``{% include ... %}`` directive without raising warnings. + __ignore__ = ["jinja2_include"] + + #: Low priority to avoid matching host- or group-specific + #: .crypt.jinja2 files + __priority__ = 50 + + def __init__(self, fname, spec): + CfgGenerator.__init__(self, fname, spec) + if not HAS_JINJA2: + raise PluginExecutionError("Jinja2 is not available") + self.template = None + encoding = Bcfg2.Options.setup.encoding + self.loader = self.__loader_cls__('/', + encoding=encoding) + self.environment = self.__environment_cls__(loader=self.loader) + __init__.__doc__ = CfgGenerator.__init__.__doc__ + + def get_data(self, entry, metadata): + if self.template is None: + raise PluginExecutionError("Failed to load template %s" % + self.name) + return self.template.render( + get_template_data(entry, metadata, self.name, + default=DefaultJinja2DataProvider())) + get_data.__doc__ = CfgGenerator.get_data.__doc__ + + def handle_event(self, event): + CfgGenerator.handle_event(self, event) + try: + self.template = \ + self.environment.get_template(self.name) + except: + raise PluginExecutionError("Failed to load template: %s" % + sys.exc_info()[1]) + handle_event.__doc__ = CfgGenerator.handle_event.__doc__ |