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  #! /usr/bin/env python  
 14   
 15  from Products.ZenHub.HubService import HubService 
 16  from twisted.web import resource, server 
 17  from twisted.internet import reactor 
 18   
 19  import xmlrpclib 
 20   
 21  import mimetypes 
 22   
 23  htmlResource = None 
 24   
 25  import logging 
 26  log = logging.getLogger("zenrender") 
 27   
 28  __doc__ = "Provide a simple web server to forward render requests" 
 29   
 30 -class Render(resource.Resource): 
 31   
 32      isLeaf = True 
 33   
 34 -    def __init__(self): 
 35          resource.Resource.__init__(self) 
 36          self.renderers = {} 
 37   
 38   
 39 -    def render_GET(self, request): 
 40          "Deal with http requests" 
 41          args = request.args.copy() 
 42          for k, v in args.items(): 
 43              if len(v) == 1: 
 44                  args[k] = v[0] 
 45   
 46          listener = request.postpath[-2] 
 47          command = request.postpath[-1] 
 48          args.setdefault('ftype', 'PNG') 
 49          ftype = args['ftype'] 
 50          del args['ftype'] 
 51          mimetype = mimetypes.guess_type('.%s'%ftype)[0] 
 52          if not mimetype: mimetype = 'image/%s'%ftype 
 53          request.setHeader('Content-type', mimetype) 
 54          def write(result): 
 55              if result: 
 56                  request.write(result) 
 57              request.finish() 
 58          def error(reason): 
 59              log.error("Unable to fetch graph: %s", reason) 
 60              request.finish() 
 61          renderer = self.renderers.get(listener, False) 
 62          if not renderer or not renderer.listeners: 
 63              raise Exception("Renderer %s unavailable" % listener) 
 64          d = renderer.listeners[0].callRemote(command, **args) 
 65          d.addCallbacks(write, error) 
 66          return server.NOT_DONE_YET 
 67   
 68 -    def render_POST(self, request): 
 69          "Deal with XML-RPC requests" 
 70          for instance, renderer in self.renderers.items(): 
 71              for listener in renderer.listeners: 
 72                  try: 
 73                      args, command = xmlrpclib.loads(request.content.read()) 
 74                      request.setHeader('Content-type', 'text/xml') 
 75                      d = listener.callRemote(str(command), *args) 
 76                      def write(result): 
 77                          response = xmlrpclib.dumps((result,), 
 78                                                     methodresponse=True) 
 79                          request.write(response) 
 80                          request.finish() 
 81                      def error(reason): 
 82                          log.error("Unable to fetch graph: %s", reason) 
 83                          request.finish() 
 84                      d.addCallbacks(write, error) 
 85                      return server.NOT_DONE_YET 
 86                  except Exception, ex: 
 87                      log.exception(ex) 
 88                      log.warning("Skipping renderer %s" % instance) 
 89          raise Exception("No renderer registered") 
 90   
 91 -    def getChild(self, path, request): 
 92          "Handle all paths" 
 93          return self, () 
 94   
 95   
 96 -    def addRenderer(self, renderer): 
 97          self.renderers[renderer.instance] = renderer 
 98   
 99 -class ZenRender(HubService): 
100   
101 -    def __init__(self, *args, **kw): 
102          HubService.__init__(self, *args, **kw) 
103          global htmlResource 
104          if not htmlResource: 
105              htmlResource = Render() 
106              reactor.listenTCP(8090, server.Site(htmlResource)) 
107          htmlResource.addRenderer(self) 
108