ifupdown2/ifupdown/template.py

   1 #!/usr/bin/python
   2 #
   3 # Copyright 2014-2017 Cumulus Networks, Inc. All rights reserved.
   4 # Author: Roopa Prabhu, roopa@cumulusnetworks.com
   5 #
   6 # template --
   7 #    helper class to render templates
   8 #
   9
  10 try:
  11     from ifupdown2.ifupdown.utils import *
  12 except ImportError:
  13     from ifupdown.utils import *
  14
  15
  16 class templateEngine():
  17     """ provides template rendering methods """
  18
  19     def __init__(self, template_engine, template_enable='0',
  20                  template_lookuppath=None):
  21         self.logger = logging.getLogger('ifupdown.' +
  22                     self.__class__.__name__)
  23         self.tclass = None
  24         self.tclassargs = {}
  25         self.render = self._render_default
  26         if template_enable == '0':
  27             return
  28         if template_engine == 'mako':
  29             try:
  30                 self.tclass = utils.importName('mako.template', 'Template')
  31             except Exception, e:
  32                 self.logger.warn('unable to load template engine %s (%s)'
  33                         %(template_engine, str(e)))
  34                 pass
  35             if template_lookuppath:
  36                 try:
  37                     self.logger.debug('setting template lookuppath to %s'
  38                             %template_lookuppath)
  39                     lc = utils.importName('mako.lookup', 'TemplateLookup')
  40                     self.tclassargs['lookup'] = lc(
  41                                 directories=template_lookuppath.split(':'))
  42                 except Exception, e:
  43                     self.logger.warn('unable to set template lookup path'
  44                                      ' %s (%s): are you sure \'python-mako\''
  45                                      'is installed?'
  46                                      % (template_lookuppath, str(e)))
  47             self.render = self._render_mako
  48         else:
  49             self.logger.info('skip template processing.., ' +
  50                     'template engine not found')
  51
  52     def _render_default(self, textdata):
  53         return textdata
  54
  55     def _render_mako(self, textdata):
  56         """ render textdata passed as argument using mako
  57
  58         Returns rendered textdata """
  59
  60         if not self.tclass:
  61             return textdata
  62         self.logger.info('template processing on interfaces file ...')
  63         t = self.tclass(text=textdata, output_encoding='utf-8',
  64                      lookup=self.tclassargs.get('lookup'))
  65         return t.render()