Source Code for Module ZenHub.services.ZenRender

  1  ########################################################################### 
  2  # 
  3  # This program is part of Zenoss Core, an open source monitoring platform. 
  4  # Copyright (C) 2007, Zenoss Inc. 
  5  # 
  6  # This program is free software; you can redistribute it and/or modify it 
  7  # under the terms of the GNU General Public License version 2 as published by 
  8  # the Free Software Foundation. 
  9  # 
 10  # For complete information please visit: http://www.zenoss.com/oss/ 
 11  # 
 12  ########################################################################### 
 13   
 14  from Products.ZenHub.HubService import HubService 
 15  from twisted.web import resource, server 
 16  from twisted.internet import reactor 
 17   
 18  import xmlrpclib 
 19   
 20  import mimetypes 
 21   
 22  htmlResource = None 
 23   
 24  import logging 
 25  log = logging.getLogger("zenrender") 
 26   
 27  __doc__ = "Provide a simple web server to forward render requests" 
 28   
 29 -class Render(resource.Resource): 
 30   
 31      isLeaf = True 
 32   
 33 -    def __init__(self): 
 34          resource.Resource.__init__(self) 
 35          self.renderers = {} 
 36   
 37   
 38 -    def render_GET(self, request): 
 39          "Deal with http requests" 
 40          args = request.args.copy() 
 41          for k, v in args.items(): 
 42              if len(v) == 1: 
 43                  args[k] = v[0] 
 44   
 45          listener = request.postpath[-2] 
 46          command = request.postpath[-1] 
 47          args.setdefault('ftype', 'PNG') 
 48          ftype = args['ftype'] 
 49          del args['ftype'] 
 50          mimetype = mimetypes.guess_type('.%s'%ftype)[0] 
 51          if not mimetype: mimetype = 'image/%s'%ftype 
 52          request.setHeader('Content-type', mimetype) 
 53          def write(result): 
 54              if result: 
 55                  request.write(result) 
 56              request.finish() 
 57          def error(reason): 
 58              log.error("Unable to fetch graph: %s", reason) 
 59              request.finish() 
 60          renderer = self.renderers.get(listener, False) 
 61          if not renderer or not renderer.listeners: 
 62              raise Exception("Renderer %s unavailable" % listener) 
 63          d = renderer.listeners[0].callRemote(command, **args) 
 64          d.addCallbacks(write, error) 
 65          return server.NOT_DONE_YET 
 66   
 67 -    def render_POST(self, request): 
 68          "Deal with XML-RPC requests" 
 69          content = request.content.read() 
 70          for instance, renderer in self.renderers.items(): 
 71              if instance != request.postpath[-1]: continue 
 72              for listener in renderer.listeners: 
 73                  try: 
 74                      args, command = xmlrpclib.loads(content) 
 75                      request.setHeader('Content-type', 'text/xml') 
 76                      d = listener.callRemote(str(command), *args) 
 77                      def write(result): 
 78                          try: 
 79                              response = xmlrpclib.dumps((result,), 
 80                                                         methodresponse=True, 
 81                                                         allow_none=True) 
 82                              request.write(response) 
 83                          except Exception, ex: 
 84                              log.error("Unable to %s: %s", command, ex) 
 85                          request.finish() 
 86                      def error(reason): 
 87                          log.error("Unable to %s: %s", command, reason) 
 88                          request.finish() 
 89                      d.addCallbacks(write, error) 
 90                      return server.NOT_DONE_YET 
 91                  except Exception, ex: 
 92                      log.exception(ex) 
 93                      log.warning("Skipping renderer %s" % instance) 
 94          raise Exception("No renderer registered") 
 95   
 96 -    def getChild(self, unused, ignored): 
 97          "Handle all paths" 
 98          return self, () 
 99   
100   
101 -    def addRenderer(self, renderer): 
102          self.renderers[renderer.instance] = renderer 
103   
104 -class ZenRender(HubService): 
105   
106 -    def __init__(self, *args, **kw): 
107          HubService.__init__(self, *args, **kw) 
108          global htmlResource 
109          if not htmlResource: 
110              htmlResource = Render() 
111              reactor.listenTCP(8090, server.Site(htmlResource)) 
112          htmlResource.addRenderer(self) 
113