plugins/omf_resctl.py

   1 #
   2 # NodeManager plugin - first step of handling omf_controlled slices
   3 #
   4
   5 """
   6 Overwrites the 'resctl' tag of slivers controlled by OMF so slivermanager.py does the right thing
   7 """
   8
   9 import os, os.path
  10 import glob
  11 import subprocess
  12
  13 import tools
  14 import logger
  15
  16 # we need this to run after sliverauth
  17 priority = 150
  18
  19 def start():
  20     pass
  21
  22 ### the new template for OMF v6
  23 # hard-wire this for now
  24 # once the variables are expanded, this is expected to go into
  25 config_ple_template="""---
  26 # we extract expires time here, even in a comment so that the
  27 # trigger script gets called whenever this changes
  28 # expires: _expires_
  29
  30 # these are not actual OMF parameters, they are only used by the trigger script
  31 :hostname: _hostname_
  32 :slicename: _slicename_
  33
  34 # OMF configuration
  35 :uid: _slicename_%_hostname_
  36 :uri: xmpp://_slicename_-_hostname_-<%= "#{Process.pid}" %>:_slicename_-_hostname_-<%= "#{Process.pid}" %>@_xmpp_server_
  37 :environment: production
  38 :debug: false
  39
  40 :auth:
  41   :root_cert_dir: /home/_slicename_/root_certs
  42   :entity_cert: /home/_slicename_/entity.crt
  43   :entity_key: /home/_slicename_/.ssh/id_rsa
  44 """
  45
  46 # the path where the config is expected from within the sliver
  47 yaml_slice_path="/etc/omf_rc/config.yml"
  48 # the path for the script that we call when a change occurs
  49 # given that we're now responsible for fetching this one, I have to
  50 # decide on an actual path - not jsut a name to search for in PATH
  51 omf_rc_trigger_script="/usr/bin/plc_trigger_omf_rc"
  52
  53 # hopefully temporary: when trigger script is missing, fetch it at the url here
  54 omf_rc_trigger_url="http://git.mytestbed.net/?p=omf.git;a=blob_plain;f=omf_rc/bin/plc_trigger_omf_rc;hb=HEAD"
  55 def fetch_trigger_script_if_missing (slicename):
  56     full_path="/vservers/%s/%s"%(slicename,omf_rc_trigger_script)
  57     if not os.path.isfile (full_path):
  58         retcod=subprocess.call (['curl','--silent','-o',full_path,omf_rc_trigger_url])
  59         if retcod!=0:
  60             logger.log("Could not fetch %s"%omf_rc_trigger_url)
  61         else:
  62             subprocess.call(['chmod','+x',full_path])
  63             logger.log("omf_resctl: fetched %s"%(full_path))
  64             logger.log("omf_resctl: from %s"%(omf_rc_trigger_url))
  65
  66 def GetSlivers(data, conf = None, plc = None):
  67     logger.log("omf_resctl.GetSlivers")
  68     if 'accounts' not in data:
  69         logger.log_missing_data("omf_resctl.GetSlivers",'accounts')
  70         return
  71
  72     try:
  73         xmpp_server=data['xmpp']['server']
  74         if not xmpp_server:
  75             # we have the key but no value, just as bad
  76             raise Exception
  77     except:
  78         # disabled feature - bailing out
  79         logger.log("omf_resctl: PLC_OMF config unsufficient (not enabled, or no server set), -- plugin exiting")
  80         return
  81
  82     hostname = data['hostname']
  83
  84     def is_omf_friendly (sliver):
  85         for chunk in sliver['attributes']:
  86             if chunk['tagname']=='omf_control': return True
  87
  88     for sliver in data['slivers']:
  89         # skip non OMF-friendly slices
  90         if not is_omf_friendly (sliver): continue
  91         slicename=sliver['name']
  92         expires=str(sliver['expires'])
  93         yaml_template = config_ple_template
  94         yaml_contents = yaml_template\
  95             .replace('_xmpp_server_',xmpp_server)\
  96             .replace('_slicename_',slicename)\
  97             .replace('_hostname_',hostname)\
  98             .replace('_expires_',expires)
  99         yaml_full_path="/vservers/%s/%s"%(slicename,yaml_slice_path)
 100         yaml_full_dir=os.path.dirname(yaml_full_path)
 101         if not os.path.isdir(yaml_full_dir):
 102             try: os.makedirs(yaml_full_dir)
 103             except OSError: pass
 104
 105         config_changes=tools.replace_file_with_string(yaml_full_path,yaml_contents)
 106         logger.log("yaml_contents length=%d, config_changes=%r"%(len(yaml_contents),config_changes))
 107         # would make sense to also check for changes to authorized_keys
 108         # would require saving a copy of that some place for comparison
 109         # xxx todo
 110         keys_changes = False
 111         if config_changes or keys_changes:
 112             # instead of restarting the service we call a companion script
 113             try:
 114                 fetch_trigger_script_if_missing (slicename)
 115                 # the trigger script actually needs to be run in the slice context of course
 116                 # in addition there is a requirement to pretend we run as a login shell
 117                 # hence sudo -i
 118                 slice_command = [ "sudo", "-i",  omf_rc_trigger_script ]
 119                 to_run = tools.command_in_slice (slicename, slice_command)
 120                 log_filename = "/vservers/%s/var/log/%s.log"%(slicename,omf_rc_trigger_script)
 121                 logger.log("omf_resctl: starting %s"%to_run)
 122                 logger.log("redirected into %s"%log_filename)
 123                 logger.log("*not* waiting for completion..")
 124                 with open(log_filename,"a") as log_file:
 125                     subprocess.Popen(to_run, stdout=log_file,stderr=subprocess.STDOUT)
 126                 # a first version tried to 'communicate' on that subprocess instance
 127                 # but that tended to create deadlocks in some cases
 128                 # causing nodemanager to stall...
 129                 # we're only losing the child's retcod, no big deal
 130             except:
 131                 import traceback
 132                 traceback.print_exc()
 133                 logger.log_exc("omf_resctl: WARNING: Could not call trigger script %s"%\
 134                                    omf_rc_trigger_script, name=slicename)
 135         else:
 136             logger.log("omf_resctl: %s: omf_control'ed sliver has no change" % slicename)