Source Code for Module backend.server.handlers.xmlrpc.getMethod

  1  # Retrieve action method name given queued action information. 
  2  # 
  3  # Client code for Update Agent 
  4  # 
  5  # Copyright (c) 2008--2016 Red Hat, Inc. 
  6  # 
  7  # This software is licensed to you under the GNU General Public License, 
  8  # version 2 (GPLv2). There is NO WARRANTY for this software, express or 
  9  # implied, including the implied warranties of MERCHANTABILITY or FITNESS 
 10  # FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2 
 11  # along with this software; if not, see 
 12  # http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt. 
 13  # 
 14  # Red Hat trademarks are not licensed under GPLv2. No permission is 
 15  # granted to use or replicate Red Hat trademarks that are incorporated 
 16  # in this software or its documentation. 
 17  # 
 18  # 
 19  # An allowable xmlrpc method is retrieved given a base location, a 
 20  # hierarchical route to the class/module, and method name. 
 21  # 
 22   
 23  import os 
 24  import string 
 25  import sys 
 26  from spacewalk.common.usix import ClassType 
 27  from distutils.sysconfig import get_python_lib 
 28   
 29  from spacewalk.common.usix import raise_with_tb 
 30   
 31 -class GetMethodException(Exception): 
 32   
 33      """Exception class""" 
 34      pass 
 35   
 36   
 37 -def sanity(methodNameComps): 
 38      """ Verifies if all the components have proper names.""" 
 39      # Allowed characters in each string 
 40      alpha = string.lowercase + string.uppercase 
 41      allowedChars = alpha + string.digits + '_' 
 42      for comp in methodNameComps: 
 43          if not len(comp): 
 44              raise GetMethodException("Empty method component") 
 45          for c in comp: 
 46              if c not in allowedChars: 
 47                  raise GetMethodException( 
 48                      "Invalid character '%s' in the method name" % c) 
 49          # Can only begin with a letter 
 50          if comp[0] not in alpha: 
 51              raise GetMethodException( 
 52                  "Method names should start with an alphabetic character") 
 53   
 54   
 55 -def getMethod(methodName, baseClass): 
 56      """ Retreive method given methodName, path to base of tree, and class/module 
 57          route/label. 
 58      """ 
 59      # First split the method name 
 60      methodNameComps = ['spacewalk'] + string.split(baseClass, '.') + string.split(methodName, '.') 
 61      # Sanity checks 
 62      sanity(methodNameComps) 
 63      # Build the path to the file 
 64      path = get_python_lib() 
 65      for index in range(len(methodNameComps)): 
 66          comp = methodNameComps[index] 
 67          path = "%s/%s" % (path, comp) 
 68          # If this is a directory, fine... 
 69          if os.path.isdir(path): 
 70              # Okay, go on 
 71              continue 
 72          # Try to load this as a file 
 73          for extension in ['py', 'pyc', 'pyo']: 
 74              if os.path.isfile("%s.%s" % (path, extension)): 
 75                  # Yes, this is a file 
 76                  break 
 77          else: 
 78              # No dir and no file. Die 
 79              raise GetMethodException("Action %s could not be found" % methodName) 
 80          break 
 81      else: 
 82          # Only directories. This can't happen 
 83          raise GetMethodException("Very wrong") 
 84   
 85      # The position of the file 
 86      fIndex = index + 1 
 87      # Now build the module name 
 88      modulename = string.join(methodNameComps[:fIndex], '.') 
 89      # And try to import it 
 90      try: 
 91          actions = __import__(modulename) 
 92      except ImportError: 
 93          raise_with_tb(GetMethodException("Could not import module %s" % modulename), sys.exc_info()[2]) 
 94   
 95      className = actions 
 96      # Iterate through the list of components and try to load that specific 
 97      # module/method 
 98      for index in range(1, len(methodNameComps)): 
 99          comp = methodNameComps[index] 
100          if index < fIndex: 
101              # This is a directory or a file we have to load 
102              if not hasattr(className, comp): 
103                  # Hmmm... Not there 
104                  raise GetMethodException("Class %s has no attribute %s" % ( 
105                      string.join(methodNameComps[:index], '.'), comp)) 
106              className = getattr(className, comp) 
107              # print type(className) 
108              continue 
109          # A file or method 
110          # We look for the special __rhnexport__ array 
111          if not hasattr(className, '__rhnexport__'): 
112              raise GetMethodException("Class %s is not RHN-compliant" % 
113                                       string.join(methodNameComps[:index], '.')) 
114          export = getattr(className, '__rhnexport__') 
115          if comp not in export: 
116              raise GetMethodException("Class %s does not export '%s'" % ( 
117                  string.join(methodNameComps[:index], '.'), comp)) 
118          className = getattr(className, comp) 
119          if type(className) is ClassType: 
120              # Try to instantiate it 
121              className = className() 
122          # print type(className) 
123   
124      return className 
125   
126   
127  #----------------------------------------------------------------------------- 
128  if __name__ == '__main__': 
129      # Two valid ones and a bogus one 
130      methods = [ 
131          'a.b.c.d.e.f', 
132          'a.b.c.d.e.foo.h', 
133          'a.b.c.d.e.g.h', 
134          'a.b.d.d.e.g.h', 
135          'a.b.d.d._e.g.h', 
136          'a.b.d.d.e_.g.h', 
137          'a.b.d.d.e-.g.h', 
138          'a.b.d.d..g.h', 
139      ] 
140   
141      for m in methods: 
142          print("----Running method %s: " % m) 
143          try: 
144              method = getMethod(m, 'Actions') 
145          except GetMethodException: 
146              e = sys.exc_info()[1] 
147              print("Error getting the method %s: %s" % (m, 
148                                                         string.join(map(str, e.args)))) 
149          else: 
150              method() 
151  #----------------------------------------------------------------------------- 
152